REVISTA TERRA LATINOAMERICANA <h4><span style="float: right; color: #111111; font-family: 'helvetica neue',helvetica,arial,verdana,sans-serif; font-size: 14.4px; font-style: normal; font-variant: normal; letter-spacing: normal; line-height: 18.72px; text-align: justify; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; display: inline ! important; background-color: #ffffff;">ISSN Electrónico 2395 - 8030.</span></h4> en-US (Dr. Bernardo Murillo Amador) (Cristopher Escalera de la Rosa) Mon, 18 Jan 2021 13:36:53 +0000 OJS 60 Portada Interna 39 Rosa Maria López-Atilano Copyright (c) Mon, 18 Jan 2021 00:00:00 +0000 Editorial Committee 39 Rosa Maria López-Atilano Copyright (c) Mon, 18 Jan 2021 00:00:00 +0000 Index 39 Rosa Maria López-Atilano Copyright (c) Mon, 18 Jan 2021 00:00:00 +0000 Evaluation of sugar cane biochar in the development of Pinus greggii Engelm. ex Parl in forest nursery <p>There is a need to replace components of substrates for the development of seedlings in forest nursery, with low-cost products and especially with local and renewable materials. Sugarcane bagasse biochar is lightweight, porous and has a high-water retention capacity. Therefore, the objective of this study was to evaluate the response of biochar based on sugarcane bagasse to produce white pine (Pinus greggii Engelm. ex Parl) plants under nursery conditions. Four treatments were evaluated: (a) biochar with forest soil, (b) forest substrate (composed of 12.5% peat moss, 12.5% agrolite, 25% vermiculite, 50% pine bark), (c) biochar with forest substrate, both in a 1:9 ratio (biochar:soil, biochar:substrate), and (d) forest soil. The effect of fertilization (N, P and K) and biochar on the performance of treatments in soil and forest substrate was evaluated. The growth variables evaluated were plant height, stem diameter, total aerial biomass, total root biomass, aerial/root biomass ratio, and the concentration of accumulated nutrients (N, P, Ca, K, Na and Mg) in the aerial and root parts. The results obtained indicate that as a consequence of the addition of biochar to the soil and fertilization, the height, diameter, biomass (aerial and total) of Pinus greggii were similar to obtained in forest substrate, alone or combined with biochar. These results were associated with the addition of biochar to the soil that increased the absorption of N and its concentration in the aerial biomass, and favored the availability of Mg, Ca, K and P, these last two elements added in fertilization. It is concluded that the combination of biochar and soil in a ratio (1: 9) (p/p) with the addition of fertilizer (N, P and K) can be used in the development of Pinus greggii Engelm ex Parl in the nursery.</p> Guadalupe Pérez-González, Claudia Hidalgo-Moreno, Jorge D. Etchevers-Barra, Ben de Jong, Sergio Salgado-García, Esteban Valtierra-Pacheco, Miguel Ángel López-López Copyright (c) 2022 REVISTA TERRA LATINOAMERICANA Wed, 05 Jan 2022 16:47:20 +0000 Distribution of soil aggregates and associated organic carbon in relation to different types of land uses and depths <p>The aggregates distribution (masses) in different land uses and depths allows characterizing their structural stability and understanding the changes in the dynamics of carbon and mass distribution depending on the aggregates size. To model the distribution and mass of aggregates related to depth for different land uses, seven land uses were analyzed: Abies forest (BAr), Cupressus forest (BCr), Quercus forest (BQr), Abies forest with forest f ire (BAq), Quercus secondary forest (Bs), grassland (Pz) and agriculture with traditional tillage (Agt), all located on Mount Tlaloc in Texcoco, State of Mexico. Additionally, a conservation agriculture site (Agc) was selected in the lower part of Mount Tlaloc. To develop a general model, we started from the analysis of the patterns of the distribution of the accumulated mass (M acum) and accumulated carbon (C acum) in relation to the size of the aggregates, for different soil depths in each land use. Based on the adjusted mathematical models, a general model of n order kinetics was proposed as a cause for the observed solutions. The statistical adjustments were excellent (R2 &gt; 0.99, generally).</p> Edgar Barrales-Brito, Fernando Paz-Pellat, Alma S. Velázquez-Rodríguez, Claudia Hidalgo-Moreno, Jorge D. Etchevers-Barra Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Thu, 23 Dec 2021 17:30:16 +0000 Controlling factors of ecosystem and soil respiration in a xeric shrubland in the Chihuahuan Desert, Mexico <p>In the terrestrial carbon cycle is very relevant to identify the influence of soil in the CO2 released to the atmosphere, which is linked to multiple biotic and abiotic drivers. Arid ecosystems dominate the trend and interannual variability of the land CO2 sink. This pattern is mainly controlled by temperature, precipitation, and shortwave radiation. Thus, these environments are characterized by a wide variability of water availability, which causes the CO2 efflux to be highly variable in time, challenging our model capacities. This study aims to understand the ecosystem CO2 fluxes and their controlling mechanisms from the Chihuahuan Desert in Northeast Mexico. We explore the average contribution of the Rsoil (1.30 mmol m-2&nbsp;s‑1) to Reco (1.76 mmol m-2&nbsp;s‑1), while identifying the controlling mechanisms of both on an annual scale. The structural equation model constructed showed a good f it for the data, explaining 50% and 93% of the annual variance of Rsoil and Reco, respectively. According to this model, Rsoil was mainly controlled by the air temperature, and Reco by soil water content. Unexpectedly, vapor pressure def icit was the most weight variable with a direct negative effect on Reco, supporting the idea that the vegetation component has a crucial role in the CO2 efflux of this ecosystem. This study highlights the&nbsp;importance of include multiple factors in the models of the C cycle.</p> Emmanuel F. Campuzano-Granados, Josué Delgado-Balbuena, Dulce Yaahid Flores-Rentería Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Thu, 23 Dec 2021 17:25:29 +0000 Soil organic carbon and particulate carbon in water in riparian systems under different land use <p>Overexploitation of hydric resources and lack knowledge of interactions between riparian vegetation, water and soil, generates loss of environmental services and ecological degradation in many mountainous riparian environments. In order to characterizing riparian-soils and non-riparian soils, soil organic carbon content and particulate carbon was evaluated as ecological degradation indicators and also degree of association between physical and chemical water properties with those of riparian soils. Twenty sites were selected in lotic systems between 1900-3900&nbsp;m on slopes Western in Iztaccíhuatl-Popocatépetl National-Park and influence zone. Also variability soil organic carbon content was evaluated at 1 and 5&nbsp;m from stream (riparian soils) and also at more than 5 m from river (non-riparian soils) in different types of land use. Results showed signif icant relationships between soil organic carbon, electrical conductivity, pH, total nitrogen and available phosphorus with water properties (temperature, pH, conductivity, nitrates, ammonia, total phosphorus, dissolved oxygen, biochemical oxygen demand and particulate organic carbon). An inverse relationship was observed between soil organic carbon content of with particulate organic carbon, nitrates and nitrites, conductivity and dissolved oxygen. No signif icant differences were found in riparian-soils organic carbon (1 and 5 m), but there were signif icant differences in non-riparian soils organic carbon. Both soil organic carbon and water organic carbon particulate contents showed signif icant differences with respect to land use. Organic carbon contents in preserved riparian soils were higher than 240 Mg SOC ha-1 but in riparian-soils of degraded sites almost f ifty times smaller (5 Mg SOC ha-1).</p> Eloísa A. Guerra-Hernández, Gerardo Cruz-Flores, Jorge D. Etchevers-Barra Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Thu, 23 Dec 2021 16:56:18 +0000 Soil organic carbon predictions across Mexico at 1 m of soil depth and 90 m of spatial resolution (1999-2009) <p>Studies of spatial variation of soil organic carbon (SOC) are essential to improve knowledge about the global carbon cycle. This work documents the development of a digital SOC map for Mexico at 1 m of soil depth and at 90 m of spatial resolution representative of the period 1991-2009. A model ensemble of regression trees with a recursive elimination of variables explains 54% of the total variability using a cross-validation technique of independent samples. The predictive model produces an average error of 0.54 kg m2 of SOC at 1 m depth. The limitations of the proposed map and the research opportunities to improve the accuracy in future work are discussed. A total of 16.03±4.24 Pg of SOC is estimated in the f irst meter of mineral soil for the Mexican territory. This result is conservative compared to previous works (global and national). In this study we provide a reference framework on digital soil mapping useful for enabling state and municipal SOC monitoring programs with low computational cost.</p> Mario Guevara, Rodrigo Vargas Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Thu, 23 Dec 2021 16:49:43 +0000 Production of habanero pepper seedlings with organic and biological fertilization <p>Chemical fertilization needs to be replaced in cultivation systems. Thus, this study proposes the alternative of combining compost with liquid organic fertilizers and biofertilizers to obtain habanero pepper seedling quality. The objective is to evaluate two liquid organic fertilizers in combination with Purpureocillium lilacinum and Beauveria brongniartii in growth, nutritional concentration and quality of habanero pepper seedlings grown in peat moss/compost substrate to substitute chemistry fertilization. A completely randomized experimental design was used with a bifactorial arrangement: (1) liquid organic fertilizers (vermicompost leachate and the commercial product Pez Terra®, diluted in water in a 1:200 ratio); (2) biofertilizers (B. brongniartii and P. lilacinum) and a control (25% Steiner’s nutrient solution) group were also evaluated. The seedlings treated with the commercial product increased their growth, Soil Plant Analysis Development (SPAD) units, N, P and K concentrations, and quality with P. lilacinum inoculation; seedling height, stem diameter, leaf area, N concentration and slenderness index increased, with respect to B. brongniartii. The interaction of the commercial fertilizer and P. lilacinum, and use of peat moss/compost substrate 1:1 (v/v) increased seedling height by 10%, leaf area by 35%, N and P concentrations by 57% and 35%, respectively, and slenderness index by 8% compared to the seedlings that were produced with Steiner’s 25% nutrient solution and peat moss. Therefore, this combination was considered viable for the production of habanero pepper seedlings and may substitute chemistry fertilization.</p> Jonás Alan Luna-Fletes, Elia Cruz-Crespo, Álvaro Can-Chulim, Wilberth Chan-Cupul, Gregorio Luna-Esquivel, Juan Diego García-Paredes, Oscar Raúl Mancilla-Villa Copyright (c) 2021 TERRA LATINOAMERICANA Tue, 30 Nov 2021 16:56:12 +0000 Nutrient supply curves and critical nutrient concentrations for Pinus patula Schl. et Cham. at the nursery stage <p>Monitoring of the nutrient status of forest seedlings during the nursery stage is critical to ensure plant quality and increase its probability of survival after transplantation. At present, there are no nutritional standards that allow monitoring of the nutrient status of Pinus patula seedlings in the nursery. The objective of the present study was to derive nutrient supply curves as well as a set of foliar critical nutrient concentrations for seedlings of this species. Using the hydroponics sub-irrigation technique, an experiment was set up to provide five increasing concentrations of nitrogen, five of phosphorus, and five of potassium within the nutrient solution for growing Pinus patula seedlings. The Hewitt and Smith formula was used as the base nutrient solution to implement the concentrations of the mentioned elements in the nutrient solution. A complete randomized experimental design was adopted, which had five treatments for each nutrient studied. Each treatment was fourfold replicated, and the experimental unit was a set of eight plants. Results indicate that P. patula plants react according to a sigmoidal pattern to increasing concentrations of an individual nutrient. Based on the sigmoidal models for the seedlings, the concentrations of each nutrient in the nutrient solution, which maximized growth in terms of the several morphological seedling features were derived. The critical foliar concentrations of nitrogen, phosphorus, potassium, calcium, magnesium, iron, copper, zinc, manganese, and boron were also obtained for seedlings of the studied species, whose values were: 2.273% for N, and 2762, 4889, 3287, 981, 86, 4.14, 13.7, 437, and 62 mg kg-1 for P, K, Ca, Mg, Fe, Cu, Zn, Mn, and B, respectively. Nutrient management of seedlings in the nursery influences plant morphology, so that a detailed knowledge of the effects of each nutrient on seedlings can help produce morphologically predesigned plants.</p> Ferman Juárez-Mirón, Miguel Ángel López-López, Elizabeth Estañol-Botello Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 12 Nov 2021 18:37:18 +0000 Biological indicators of lacustrine and alluvial soils in Venezuela under different land use. Part 1. Microbial activity and ecophysiological coefficient <p>Land use can affect the activities of microorganisms and alter their biochemical transformations. This study examined basal respiration and ecophysiological coefficients in Venezuelan soils in Valencia Lake basin, under three different uses: natural vegetation, sugar cane monoculture and banana monoculture with the aim of determining the influence of land use on soil biological properties. Total organic carbon (Corg), water soluble carbon and basal respiration or microbiological activity showed a significant decrease, both in alluvial and lacustrine soils, when agricultural soils were compared with those of native vegetation. The metabolic quotient (qCO2) showed differences with relation to land use with higher values in the agroecosystems under banana trees according to the sequence in decreasing order: banana &gt; natural vegetation &gt; sugar cane. Nevertheless, the metabolic efficiency quotient (qCO2 /Corg) was significantly lower (P &lt; 0.05) in soils under natural vegetation and showed the relationship between the most efficient carbon use and the nature of the available organic matter in these soils. These results reveal that both type of crop and agricultural practices exert an important influence on soil biological activity.</p> Magaly Ruiz-Dager, Jorge Emilio Paolini-Gomez Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 29 Oct 2021 02:23:00 +0000 Effect of chitosan on the vegetative propagation of cacao (Theobroma cacao L.) by stem cuttings <p>It is estimated that the world production of cacao (Theobroma cacao L.) in the future will not meet its demand due to factors such as losses derived from pests and diseases, aging trees, limited yields, and effects of climate change. The biostimulant Quitomax®, whose main bioactive ingredient is chitosan, is a growth and resistance inducer, and an antimicrobial agent with promising results in agricultural crops. However, since its effect on the rooting, establishment and growth of cacao has not been investigated, the objective of this work was to evaluate the effect of Quitomax® on two commercial varieties of cacao, and compare it with Raizyner GNS commercial product. The experimental design was a factorial arrangement with the two cacao clones (A) and three chitosan concentrations (100, 500 and 1000 mg L-1) (B), with three replicates per treatment. Untreated plants and plants treated with Raizyner GNS (5000 mg L-1) were used as controls. The biostimulant Quitomax® promoted a significant increase in the vegetative growth variables evaluated in the cacao clones compared with the controls. In regards to plant regeneration, Quitomax® decreased the levels of the unrooted stem cuttings by 18% to 50%. In addition, Quitomax® favored the growth promotion and biostimulation of cacao plants during clonal reproduction by cuttings with better results than those obtained with other commercial products such as Raizyner GNS.</p> Juan José Reyes-Pérez, Luis Tarquino Llerena-Ramos, Rommel Arturo Ramos-Remache, Miguel Angel Ramírez-Arrebato, Alejandro Bernardo Falcón-Rodríguez, Roger Alexander Pincay-Ganchozo, Tomás Rivas-García Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 24 Sep 2021 15:15:03 +0000 Pecan production improvement by zinc under drip irrigation in calcareous soils <p>Pecan trees demand a considerable amount of zinc (Zn) for the activity of Zn-dependent enzymes involved in the metabolism of proteins, sugars, carbohydrates, and auxins. Thus, the aim of this study was to evaluate the production of pecan trees with an edaphic contribution of 12 to 15 kg ha-1 of chelated zinc through drip irrigation, including the addition of a commercial microbial consortium, throughout a three-year study. The control treatment was the conventional fertilization management using foliar zinc. The methodology proposed in this study allowed to obtain an additional kg of nut per tree after three years. With the control treatment, the shoot (21 vs. 20.1 cm) and leaf (39 vs. 36.8 cm2) grew slightly better than the foliar zinc treatment, and promoted the enrichment of microbial communities in the rhizospheric soil, as well as an ectomycorrhizal colonization of 69.9%. In addition, the chelated zinc treatment applied in drip irrigation avoided night-time spraying, therefore, this management in pecan orchards offers producers an economic, ecological and sustainable option that allows them to improve yield.</p> Ana Luisa Olivas-Tarango, Socorro Héctor Tarango-Rivero, Graciela Dolores Ávila-Quezada Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 24 Sep 2021 15:08:09 +0000 Effect of different levels of evapotranspiration on leaf area, temperature, water potential and yield of forage sorghum <p>By the year 2050 the world population will have reached 9.7 billion people at a slow growth rate, which represents a serious scenario in terms of water supply and food production. Thus, the objective of this research was to determine the effect of different evapotranspiration levels on leaf area index (LAI), surface temperature (St), water potential (Yw) and yield in forage sorghum (Sorghum vulgare Pers.) under drip irrigation. The study was carried out in the summer of 2019 at the facilities of Campo Experimental la Laguna in Matamoros, Coahuila, México. Three evapotranspiration levels (ET) (60, 80 and 100%) were evaluated to indicate the laminar water flow to apply with the drip irrigation treatments and a control treatment (flood irrigation), using two varieties of sorghum tolerant to drought and high yield, Super Sorgo (SS) and Sorgo Silo Miel (SSM). The randomized block experimental design was divided in plots with four replicates. A statistically significant difference (P&nbsp;≤&nbsp;0.05, Tukey) was observed in green and dry yield between irrigation treatments and varieties. The highest yields were observed in treatments of 80 and 100% ET, in the SSM variety. The SS variety had its best yields in drip irrigation treatments (80 and 100% ET), but with flood irrigation, yield decreased by 26%. In general, the different laminar irrigation flow affected the LAI, ST, Yw and yield with the treatment of 60%, which was the most affected reducing its yield by 25%. The volume of water applied in drip irrigation treatments was 24 to 39% less than that applied in flood irrigation.</p> Felipe Zavala-Borrego, Arturo Reyes-González, Vicente De Paul Álvarez-Reyna, Mario García-Carrillo, Víctor M. Rodríguez-Moreno, Pablo Preciado-Rangel Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 27 Aug 2021 20:45:41 +0000 Vermicompost extract as a basal medium in the in vitro multiplication and rooting stage of Dasylirion cedrosanum <p>Dasylirion cedrosanum is a native species of the Chihuahuan Desert that is economically important for alcohol production, which has caused its looting and deforestation. In the micropropagation technique, the Murashige and Skoog (MS) basal medium is the most widely used, this basal medium increases costs at the commercial level. The objective of this work was to compare the MS medium with an organic basal medium made from a vermicompost extract (EV) in the multiplication and rooting stages of D. cedrosanum. Seeds were established in MS medium for germination. Then, the seedlings obtained were used as secondary explants for the multiplication stage. In the multiplication stage, seven treatments were evaluated under a completely randomized design with 10 replications. A control (MS medium) and six EV concentrations (30, 25, 20, 15, 10 and 5 mL L-1) were compared. Our results showed the highest sprout formation in the control treatment (8.25 sprouts per explant). Whereas in the EV base treatments, the 25 ml L‑1 concentration exhibited the highest number of sprouts (3 sprouts per explant). It is worth noting that no significant differences were found between the control and the 25 ml L-1 concentration treatments in terms of the number of variables and leaf length. In the rooting stage, there was no significant difference between treatments in the root number. The MS medium and 10 ml L-1 of EV was not statistically different according to root length (6.53 and 5.99 cm, respectively), the 10 ml L-1 concentration of EV surpassed the MS in root width (1.13 mm). The EV based medium at a concentration of 10 ml L-1 can be used to completely to replace the MS medium in the rooting stage of D. cedrosanum.</p> Ricardo Israel Ramírez-Gottfried , Cristo Omar Puente-Valenzuela , Jorge Armando Chávez-Simental, Bernardo Espinosa-Palomeque, Mario García-Carrillo, Reyna Roxana Guillén-Enríquez, Guillermo González-Cervantes Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 27 Aug 2021 20:45:29 +0000 Substrates and indole-3-butyric acid in raspberry propagation <p>In order to contribute to the knowledge concerning the asexual spread of Rubus idaeus L., we established an experiment where the objective was to evaluate, in two consecutive years (2017 and 2018), the effects of different concentrations of indole-3-butyric acid (IBA) and types of substrates over the propagation efficiency from root cuttings with different raspberry varieties under greenhouse conditions. Compost materials with a high content of organic matter, sand and a clay-loamy substrate were used as rooting medium, with concentrations of 1, 5 and 10 mEq L-1 of IBA. The variables evaluated were: production of new plants over time, percentage of survival of transplanted plants with IBA treatments and substrate efficiency. The results showed statistical differences in the dynamic production of new shoots in the varieties studied. The Heritage variety exhibited the greatest emission of new shoots from the root in the two years of study. The concentrations of IBA (1, 5 and 10 mEq L-1) affected the survival rate of the transplanted plants, where the control treatment showed the greatest survival efficiency. The substrate with a high content of organic matter was the most suitable depending on the rooting efficiency of transplanted plants in individual pots. We conclude that IBA applications affect the rooting efficiency in raspberry plants, this is due to the fact that these are very succulent plants, which limits the effect of the rooting hormone.</p> María Noemí Frías-Moreno, Guadalupe Isela Olivas-Orozco, Gustavo Adolfo González-Aguilar, Juan Luis Jacobo-Cuellar, Ofelia Adriana Hernández-Rodríguez, Damaris Leopoldina Ojeda-Barrios, Verónica Ordóñez-Beltrán, Rafael Ángel Parra-Quezada Copyright (c) 2021 Terra Latinoamericana Fri, 27 Aug 2021 20:45:16 +0000 Infiltration control in a volcanic regolith with different sealing techniques <p>In the upper part of the municipality of Huasca de Ocampo, Hidalgo, the soil (regolith) derives from weathering of volcanic materials and is characterized by high rates of water infiltration (13.25 mm day-1), which causes critical difficulties to store water. Our study aimed at evaluating –in terms their permeability and economic cost– different sealing techniques to reduce infiltration in a reservoir area excavated over residual volcanic soil. The physical, chemical, and mechanical features of the soil were measured. Different treatments (46) to seal the soil were tested. The soil permeability coefficient was measured in two stages in a constant load permeameter to compare the effect through time. The permeability data were subjected to an analysis of variance (ANOVA) and the comparison of means with the least significant difference (LSD) in R Software at a significance level of α = 0.05. An economic analysis was conducted using the permeability results, comparing the unitary cost of treatments against the geomembrane cost. According to our results, in terms of economic costs and infiltration control, treatments with particle dispersants (sodium carbonate, sodium tripolyphosphate and sodium phosphate) are recommended, although maintenance applications must be considered every two or three years. The use of sand-cement and sodium bentonite were highly effective, and while these are costly materials, they constitute a long-lasting alternative.</p> Magdalena Francisco-Catarina, Demetrio Salvador Fernández-Reynoso, Rogelio Carrillo-González, Daniel Hernández-Díaz, José Donaldo Ríos-Berber, Patricio Sánchez-Guzmán Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 30 Jul 2021 01:45:31 +0000 Biofortification with selenium increases bioactive compounds and antioxidant capacity in tomato fruits <p>The objective of biofortification is the human consumption of high nutritional quality food, rich in micronutrients. Selenium (Se) is an essential micronutrient in human nutrition, and its essentiality has not been evidenced in plants. However, its application in crops and subsequent consumption can mitigate the deficiency of this micronutrient in the diet of human populations. This work analyzes the capacity of sodium selenite (Na2SeO3) to increase yield, biosynthesis of bioactive compounds and their accumulation in tomato fruits. For this, five treatments were applied via nutrient solution: 0, 2, 4, 6, and 8 mg L-1. At harvest, the nutraceutical quality and the accumulation of Se in fruits were quantified, as well as the productivity of tomato plant. Biofortification was positively affected by the biosynthesis of phytochemical compounds and their concentration in fruit, although tomato yield decreased. The incorporation of Se in nutritive solution is an alternative to increase both the biosynthesis of phytochemical compounds and the concentration of this element in tomato fruits with the possibility of improving public health through its consumption.</p> Pablo Preciado-Rangel, Luis Guillermo Hernández-Montiel, Ricardo David Valdez-Cepeda, Efraín de la Cruz-Lázaro, Liliana Lara-Capistrán, Bilagi Morales-Morales, Jazmín Monserrat Gaucin-Delgado Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Wed, 28 Jul 2021 23:23:57 +0000 Kinematic and stress analysis of three blade designs for soil aeration roller <p>In the present study, the kinematic and stress analysis of an aerator roller with blades was performed. The trajectories of the aerator roller blades were obtained, which included the rotational and translational movements on the ground. Longitudinal underground areas and volumes of the cracks were calculated for rectangular blades (Type A), symmetric triangular (Type 1) and asymmetric triangular (Type 2) blades. The results of the kinematic analysis reported that type A blades significantly modified soil with respect to the other two. Normal forces were calculated numerically and per finite element, obtaining for blade type 1 numerically calculated forces of 4.52 MPa in the upper zone of the element and -7.06 MPa in its lower zone. The normal stress calculated per finite element were found in the range from 3.66 to 6.52 MPa for the upper part of the element and -7.8 MPa for its lower part. For type 2 design, a normal stress was obtained numerically of 8.83 MPa. The normal stress calculated per finite element was found in the range from 3.95 to 12.86 MPa.</p> José Antonio Yam-Tzec, Miguel Ángel Peña-Peralta, Eugenio Romantchik-Kriuchkova, Álvaro Morelos-Moreno Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 23 Jul 2021 19:13:06 +0000 Phosphorus forms and distribution in Andisol under contrasting land-use systems in central Mexico <p>Conversion of forest to conventional farming systems may affect phosphorus (P) distributions and availability, particularly in P-limited soils. The objective of this study was to evaluate the effect of land use (native forest and avocado farming systems) on forms, distribution, and availability of P in soil. Soil samples (Andisol) from three sites cultivated with conventional farming and others from a contiguous native pine forest area were included. Soil Po and Pi fractions and microbial P were sequentially extracted after seven and 28-days (d) of incubation, respectively. In cultivated soil, total P was mostly represented by inorganic fractions (66 to 78%). Pi was mainly composed of easily mineralized P (Bic-Pi), moderately stable (NaOH0.1-Pi) and relatively insoluble fractions (Residual-Pi). However, Po proportion (29%) decreased under cropped soil due to depletion of soil organic matter. In contrast, in native forest soils, more than 48% of P was extracted in microbial biomass, Bic-Po, and NaOH0.1-Po fractions. The distribution of soil P fractions was associated with soil use type. Conventional farming systems stimulated P retention in Fe-Al oxides (NaOH0.1-Pi and Residual-Pi) and decreased P availability. Compared to cultivated soil, the higher organic P proportion under forest corresponded to higher organic matter (OM) and microbial P, which highlights the potential relevance of SOM and microbial P in sustaining P availability in P-limited acidic soils. Sustainability in cropped systems could be enhanced by promoting adequate management practices aimed at increasing soil organic P storage and reducing soil chemical reactions that absorb, occlude or precipitate applied inorganic P.</p> Daniel Tinoco-Varela, Jeannette S. Bayuelo-Jiménez Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 23 Jul 2021 18:23:38 +0000 Chemical and physical characterization of substrates enriched with minerals and compost <p>Substrates are an important component in hydroponic systems, and hence, the objective of our study was to evaluate the addition of compost and mineral mixture of zeolite-dolomite to improve the chemical and physical characteristics of substrates required to produce Capsicum pubescens. Two substrate combinations were used (tezontle and sawdust, and tezontle, sawdust and compost), as well as two concentrations of K in Steiner Solution (50 and 100%), and three levels of mineral mixture (0, 40 y 80 cm3 L-1), generating a set of 12 treatments in subdivided plots: the large plot corresponded to the concentration of K, the median plot comprised the two substrate combination and the small plot comprised the mineral blending inputs. The effect of the different treatments on the properties of bulk density, humidity, particle diameter, porosities, pH, EC, OM and OC content, C/N ratio, CEC and foliar nutrition content was assessed. Bulk density, humidity and porosities were not significantly affected. In regard to granulometry, although there were differences between treatments, diameters were fitted to &lt;2.50 mm. The pH was not affected by treatments, while EC increased significantly (1 dS m-1) by the compost; and OM content was &lt;30% on the substrates with the mineral mixture. The C/N ratio of substrates to compost was &lt;19% due to N degradation and release. CEC was &gt;8 in treatments with compost, favoring nutrient retention in the substrate and their increase in plant tissue. Our results indicate that in substrates without compost, EC and bulk density decreased when 50% K was applied, however, the physical properties resembled the optimal, where the control treatment showed the lowest quality. The addition of compost increased the content of N, P, Ca and CEC in the substrates.</p> Víctor Manuel Montoya-Jasso, Víctor Manuel Ordaz-Chaparro, Gerardo Sergio Benedicto-Valdés, Alejandrina Ruiz-Bello, Jesús Manuel Arreola-Tostado Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Tue, 20 Jul 2021 22:10:27 +0000 An improved method for extraction of microbial DNA from alkaline-saline soil <p>A modified method for the direct extraction of DNA from alkaline-saline soils with minimum DNA fragmentation and a possible reduction in chimera formation during polymerase chain reaction (PCR) was developed. The commercial extraction kit Power Soil DNA (Mo Bio™ Laboratories, Inc.) was used as a reference technique. The method reported here was based on cell lysis employing ethylenediaminetetraacetic acid (EDTA), sodium dodecyl sulfate (SDS), and cell disruption with mechanical force with FastPrep-24™ equip followed by one cycle of freezing at -40 °C for 60 min and thawing at 65 °C for 20 min. The extraction method was tested for allophonic soils with large concentrations of organic matter, fulvic and humic acids, electrolytic conductivity (EC) ranging between 2.6 dS m-1 and 39.9 dS m-1, and pH between 8.8 and 10.9. The yield of DNA extracted depended on soil type, i.e., DNA extracted from soil varied between 2.35 (Texcoco-2) to 3.66 (Texcoco-1) μg DNA g-1 soil. The proposed method in this study produced enough DNA with yield and quality for PCR amplification of 16S rDNA when bovine serum albumin (BSA) was added to the reaction buffer. The DNA obtained had sufficient quality and yield for later use for 16S sequencing or possible use in other sequencing technologies, e.g. whole metagenome shotgun sequencing.</p> Valentín Pérez-Hernández, Mario Hernández-Guzmán, César Valenzuela-Encinas, Rocío Alcántara-Hernández, Isabel Estrada-Alvarado, Luc Dendooven, Rodolfo Marsch, Federico Gutiérrez-Miceli, Víctor M. Ruíz-Valdiviezo, Joaquín A. Montes-Molina Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Tue, 29 Jun 2021 21:49:23 +0000 Response of wheat flour varieties in three types of soils in northern Mexico <p>It is necessary to update the technology on the agronomic response of new wheat varieties in relation to agro climatic conditions in order to provide alternatives with higher yields and grain quality. The objective of the study was to test three types of soil in the northwest of the state of Chihuahua for the following wheat seeds: Rayon-F89, Roelfs-F2007, Norteña-F2007, Cachanilla-F2000, Delicias-F81, Kronstad-F2004 and Luminaire-F2012. The experimental design was completely randomized with five replications; where the experimental unit was one m2 and the means were separated with the multiple comparison by Tukey test at 0.05. The agronomic practices were in accordance with those of the farmer's management. The data registered of the following variables were protein content in grain, plant height, grain moisture, test weight, ear length, and grains per ear, grain yield and total biomass. Relevant results regarding grain yield by soil type were the Rayón F-89 variety with 9.32 Mg ha-1 at El Camello site (Calcisol soil); the Kronstad variety with 7.9 Mg ha-1 at the El Capulin site (Vertisol soil); and the Roelfs variety with 11.3 Mg ha-1 at the Placitas site (Fluvisol soil). No significant effect was detected between varieties for test weight. Grain protein content varied from 10.4 to 16.7%, where the Delicias variety had the highest content in Fluvisol soil, that is, the effect of the variety was more important than the locality for protein, while for humidity the locality influenced more. The Kronstad, Roelfs and Rayon varieties are suggested for the production areas in the northwestern part of the state of Chihuahua.</p> Juan Pedro Flores-Márgez, Baltazar Corral-Díaz, Pedro Osuna-Ávila, Joel A. Hernández-Escamilla Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Tue, 29 Jun 2021 21:22:49 +0000 The backyard of Tlaxcala. An approach to its composition <p>The backyard is an agroecosystem located near the home and fulf ills several functions and provides various services; in addition, one third of the Rural Production Units in Tlaxcala have this agroecosystem. In the mexican state of Tlaxcala, México, the primary sector is the one that contributes the least to the gross domestic product; it is divided into 60 municipalities and 66% of its territory is used for agricultural, livestock and forestry activities and little is known about this agroecosystem. The objective of the research was to make an approximation of its composition with respect to the plant and animal species found in the backyard. The Registry of Agricultural Producers of the State of Tlaxcala, Mexico, carried out by the National Institute of Statistics and Geography (INEGI) was used; as a member of the work team, a copy of the original database was obtained informally, which consisted of a total of 53 968 basic information cards; of that total, 17&nbsp;236 reported backyard activities. The information was analyzed using frequency tables of data grouped and sorted into classes for both plant and animal species. Regarding the composition of the main vegetable species produced in the backyard, fruit trees such as peaches and corn stand out. Of the animal species produced, cattle and poultry are the most produced. On average, 91.15% of what is produced in the backyard is for self-consumption; the average area of the backyard was 215 m2. The composition of the Tlaxcala backyard was determined in terms of plant and animal species of certain economic importance; the results reported here can be useful for other research that continues with the characterization of the structure, composition and functioning of the backyard in the state of Tlaxcala.</p> Andrés María-Ramírez Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Mon, 28 Jun 2021 17:20:03 +0000 Effect of the disposal of coffee wet milling residues on the physical and chemical characteristics of natural flowing water <p>Coffee wet milling is a process that demands large quantities of water, and produces mucilage and pulp that are discharged into surface water. The objective of this study was to analyze the physical and chemical properties of the water in Cuxtepec and Cabañas rivers in the municipality of Concordia, Chiapas, Mexico. In these water masses, coffee wet milling subproducts are discharged during the harvest. Sampling sites were San Pedro stream, Cabañas river, rancheria 30 de Agosto and Cuxtepec river. Water samples were obtained in October and December, 2016, and January, April and June, 2017. The following parameters were determined: pH, electrical conductivity (EC), total dissolved solids (TDS), total suspended solids (TSS), sedimentable solids (SS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), total nitrogen (TN), ammonia (NH4), total phosphorus (TP), water hardness (WH), water temperature (WT), and air temperature (AT). COD and BOD content varied from site to site, with maximum values of 7.7 and 1.25 mg L-1, respectively. This low concentration allowed for high oxygen level (7.99 mg L-1). The TDS load was 149.7 mg L-1 and pH was 8.9, indicating favorable conditions for aquatic life. In general, the values measured in groundwater under traditional coffee wet milling plants did not show levels that indicate risks for agricultural use or for consumption by animals and people inhabiting areas close to the water bodies in the region. These findings suggest a need to establish a contaminant monitoring system for the coffee-producing regions of Chiapas, and improve ecological management of residual waters produced by coffee wet milling according to pollutant concentrations.</p> Ramiro Eleazar Ruiz-Nájera, José Alfredo Medina-Meléndez, Jesús Carmona-de la Torre, Gabriel Rincón-Enriquez, Juan Manuel Sánchez-Yáñez, Deb Raj-Aryal Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 18 Jun 2021 21:53:14 +0000 Effect of the application of biochar in the corn yield in Michoacan, Mexico <p>Biochar is the product resulting from the thermo-chemical transformation of plant biomass by pyrolysis. It acts as soil enhancer and benefits agricultural production. The objective of the present study was to evaluate the effect of biochar on the corn yield and the response of agronomic variables of a commercial corn in Maravatio, Michoacan. The biochar was obtained from dry corncob biomass using a pyrolysis reactor. Finely crushed biochar was applied to clay soils at 1% (T1), 2% (T2) and control 0% (T0) rates. Doses were calculated based on topsoil (10 cm) weight. The fertilization dose was 200N-80P-150K-30S for the treatments and the control. The design was in randomized blocks with four repetitions of 9 m2 each. The comparison of means was carried out with the Tukey-Kramer technique. The results indicate an increase in the yield of 1.2 Mg ha-1 (T1) and 1 Mg ha-1 (T2), compared to the control (T0). The weight of the ear, grain per plant, cob and ear length, showed the following trend: T1 &gt; T2 &gt; T0. The stem diameter and dry weight of the plant was greater in T1. Plant height and stem diameter were higher in T2. The root depth did not show significant differences between the treatments. However, the trend in lateral root development was T2 &gt; T1 &gt; T0, which suggests a positive effect for root development and exploration that could explain the increase in yield. It is concluded that biochar is a viable alternative to increase corn production and favors the vegetative development of the plant in the eastern region of the state of Michoacan.</p> Alfredo Mondragón-Sánchez, Lenin Ejecatl Medina-Orozco, Alexander Sánchez-Duque, Verónica Núñez-Oregel Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Thu, 17 Jun 2021 21:11:14 +0000 Morphometric analysis of El Salto watershed, Durango, México <p>The integral watershed management requires an adequate characterization to identify related environmental problems and, consequently, to establish the pertinent solution guidelines. This study describes in detail the morphometric and hypsometric characteristics of El Salto watershed, Durango. This research was conducted by using a “Geographical Information System” which was strengthened with field data, shape parameters, relief and the hydrographic network were analyzed. In addition, the hypsometric curve was performed, and the hypsometric integral was calculated to determine the evolutionary phase of the watershed. The results suggest that the watershed is elongated; in addition, the relief shows a low slope (303 m) with an average slope of 2.23%, it considered moderately inclined. The drainage network is considered as fourth order; it is formed by 94 channels with a 90.53 km total length. Density and intensity drainage showed values of 2.02 km/km2 and 1.04 km, respectively, with a current frequency of 2.09 channels/km2; these are considered low values for watersheds with these dimensions. According to the value of the hypsometric integral (0.5), the watershed is in an equilibrium or maturity phase. The prevailing order of currents is 1, thus, the watershed is more susceptible to water erosion during rain events. On the other hand, due to the elongated shape of the watershed, it should be less susceptible to flooding, however, low values in density and intensity of drainage and frequency of currents were observed, it suggest that the runoff is not efficient. This study will be useful for the development of projects focused on management and conservation of natural resources, especially those aiming to reduce the loss of soil by erosion and to prescribe actions to water catchment.</p> América Guadalupe Méndez-Gutiérrez, Sacramento Corral-Rivas, Juan Abel Nájera-Luna, Francisco Cruz-Cobos, Marín Pompa-García Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Mon, 31 May 2021 22:40:39 +0000 Chemical characterization of biochar from sugarcane tips produced by hydrothermal carbonization and addition of organic catalysts <p>Biochar is a carbon-rich material obtained by thermochemical conversion produced from organic materials in an oxygen-limited environment, which can be used as a soil enhancer. The objective of the research was to evaluate the yield of converted biochar, nutrient concentration and structure of sugarcane tips biochar produced by hydrothermal carbonization and addition of organic catalysts. The experimental design was completely randomized with six replicates. Treatments were three catalysts: citric, maleic and propionic acid in 5 and 10% concentrations each, which were added during biochar production. The respective control was biochar without addition of any catalyst, for a total of seven treatments. The biomass to biochar conversion yield and the total nutrient concentration of N, P, Ca, Mg and Na were determined. The extractable concentration of the same nutrients except for Na was also determined, as well as the pH and the electrical conductivity and structure of the biochar. The highest yields of biochar made from sugarcane tips by hydrothermal carbonization were 37.8% with the addition of citric acid at 10% as catalyst, as well as 34.9 and 36.1% with the addition of maleic acid at 5 and 10%, respectively. In general, due to the total and extractable nutrient concentration of biochar, its electrical conductivity (0.30-0.46 dS m-1), as well as its microsphere structure, sugarcane tips biochar could act as a soil enhancer, especially in alkaline soils due to the acid pH of the biochar produced.</p> Carlos Alberto Pérez-Cabrera, Porfirio Juárez-López, José Anzaldo-Hernández, Irán Alia-Tejacal, Eduardo Salcedo-Pérez, Dagoberto Guillén-Sánchez, Rosendo Balois-Morales, Víctor López-Martínez, Rogelio Castro-Brindis Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Mon, 31 May 2021 22:36:19 +0000 Potato minituber production in aeroponics compared to soil and coir dust <p>Potato (Solanum tuberosum L.) is one of the main food crops for feeding the world’s population. Due to the accumulation of parasitological problems, potato growers have been forced to make a greater application of pesticides, affecting the environment and prof itability. A strategy to reduce plant health problems in potato is to start the growing season with disease-free minitubers, which are grown from certif ied plants in pathogen-free soil; however, in aeroponics or in a soilless cultivation system, a higher yield and quality of mini tubers might be obtained. Therefore, the objective of this study was to determine the effect of aeroponics on minituber production compared to the production in soil or in a substrate based on coconut coir dust. In aeroponics, a mini tuber production resulted 4.4 times higher than that obtained by plants on soil, while plants on coir dust also outperformed production on soil by 40%. Higher production of minitubers in aeroponics was associated with higher stolon production, since 2.4 times more stolons were produced than those by plants in soil. In aeroponics, 96.6% of the minitubers weighed less than 50 g and only 3.4% was greater than 50 g; in contrast, 19.8% and 24.3% of minitubers were greater than 50.1 g in plants grown in coir dust or in soil, respectively. In general, the vegetative growth of plants in aeroponics was greater than that obtained in coconut coir dust and soil.</p> David Rogelio García-Segura, Luis Alonso Valdez-Aguilar, Homero Ramírez-Rodríguez, Alejandro Zermeño-González, Martín Cadena-Zapata Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Wed, 19 May 2021 22:47:24 +0000 Biological, organic and reduced mineral fertilization in soybean (Glycine max L.) <p>Chemical mineral fertilization (CF) in soybean (Glycine max L.) is a regular practice and depends on the availability of moisture in soil. The increase in cost of agricultural inputs and loss of soil fertility drive the search for sustainable strategies. The objective of this experiment was to use biological fertilization alternatives (FB) in this crop with the Huasteca 400 variety. Treatments were (1) control, 18-46-00 (100% CF); (2) arbuscular mycorrhizal Biogea® + 50% CF; (3) arbuscular mycorrhizal INIFAP + 50% CF; (4)&nbsp;Biogea + poultry manure (1 Mg ha-1) + 50% CF; (5) Biogea + gypsum (0.5 Mg ha-1) + 50% CF; and (6)&nbsp;Bradyrhizobium japonicum (Cel Tech®) + arbuscular mycorrhiza INIFAP (Rhizophagus intraradices). Soil plant analysis development (SPAD) index was measured in stages V1, V5, and R2, and plant height in V5 and R5. Yield, grain protein, and oil percentage were quantified at harvest. The economic production analysis was determined by profitability. No statistical differences were recorded between alternative treatments and the control group. The combination between B. japonicum and R. intraradices showed the best profitability with a benefit-cost ratio of 2.6 and a profit of USD 11 890 per hectare. This alternative management of soybean nutrition can promote greater profitability and decrease due to contamination in the agroecological environment.</p> Arturo Díaz-Franco, Florencia Alejandro-Allende, Ma. Eugenia Cisneros-López, Martín Espinosa-Ramírez, Flor Elena Ortiz-Cháirez Copyright (c) 2021 Terra Latinoamericana Wed, 19 May 2021 22:39:14 +0000 Characterization of biofertilizers used in the agricultural valley of Guasave, Sinaloa, Mexico <p>The environmental imbalance that chemical fertilizers cause in soils and the need to preserve organic matter for the sustainability and productivity of agricultural systems, has resumed the use of organic fertilizers. The objective of the present study was to determine the physicochemical and microbiological characteristics as indicators of quality in organic fertilizers. The experiment was carried out in a randomized block design, four replications and seven treatments¸ T1: calcium leachate, T2: calcium humus liquid extract, T3: banana humus, T4: concentrated calcium humus, T5: vermicompost, T6: vermicompost liquid extract and control T7: fertilizer of commercial origin (control). (4) The vermicompost, banana humus and commercial fertilizers showed high values of nitrogen and phosphate. The fertilizers had lower pH and electric conductivity (EC) levels than those indicated in NOM-021-RECNAT-2000. The correlation coefficient was positive between EC and nutrients. The commercial fertilizer presented high concentrations of Cr and Pb, without exceeding the maximum permissible limits for the NOM-052-SEMARNAT-2005. As a biological response, lettuce and radish seeds had the lowest GI in banana humus, concentrated calcium humus and commercial fertilizer. The microbiological analyzes showed an absence of the Salmonella indicator and results greater than the maximum allowable limit for use in agriculture in fecal and total coliforms. Organic fertilizers are made with residues of plant, animal or both, some without adequate control, so they become a contamination problem. Due to the increasing demand for organic fertilizers, its study is important since there is no Mexican regulation that defines technical norms to establish quality characteristics in organic fertilizers to be used in agriculture. The physicochemical and biological characteristics vary depending on the material used in the elaboration, since it is a factor that must be considered to obtain a final product that provides available nutrients to the plants.</p> Luis Carlos González-Márquez, Rubén Félix-Gastélum, Jorge Antonio Sandoval-Romero, Diana Cecilia Escobedo-Urías, Rosa María Longoria-Espinoza Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Wed, 19 May 2021 22:33:56 +0000 Nutrient requirement and potassium nutrition in Persian cucumber with pruning to a single stem <p>In fertigation systems, proper management of potassium nutrition in Persian cucumber crop increases fruit quality. Similarly, nutrient extraction indexes are needed to establish mineral nutrition programs during the crop cycle. The aim of this research was to evaluate the effect of potassium nutrition and quantify the nutritional extraction in two varieties of Persian cucumber (Reehan and Khassib). The experimental design was factorial 2 × 4, the first factor was the two varieties of cucumber and the second factor the concentration of K+ in the nutrient solution, with concentrations of 5, 7, 9 and 11 meq L-1. The variables were: Cumulative fruit production (PAF), fruit number (NF), individual fruit weight (PIF), fruit diameter and total soluble solids (TSS). The analysis of variance indicated that there was an effect of factor interaction in PAF and NF (P ≤ 0.05). In both varieties, there were significant differences in all the quantified response variables, where Khassib showed the highest values (Tukey, P ≤ 0.05). For the nutritive solution factor, there were only significant differences in PAF and PIF. The highest PAF (Tukey, P ≤ 0.05) was obtained with nutrient solutions containing 9 and 11 meq K L-1; while the highest PIF occurred with 5, 7 and 9 meq K L-1. The potassium concentration in the nutrient solution showed a positive correlation with the content of total soluble solids in fruits of the Reehan variety (r = 0.999), but not in the Khassib variety (r = -0.6829). The nutritional requirement (kg) per ton of fresh fruit in Reehan was N 3.93, P 0.46, K 3.11, Ca 0.79 and Mg 1.30; while in Khassib N 5.87, P 0.49, K 3.11, Ca 0.85 and Mg 1.54.</p> Gelacio Alejo-Santiago, Sergio Guadalupe Becerra-Venegas, Rubén Bugarín-Montoya, Circe Aidín Aburto-González, Evangelina Esmeralda Quiñones-Aguilar, Gabriel Rincón-Enríquez, Cecilia Rocío Juárez-Rosete Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 14 May 2021 04:32:20 +0000 Effect of sugary substances on organic substrates degradation for compost elaboration <p>Compost is the main degradation channel for organic waste, however, the whole process requires long maturation times, which is why the search for quick ways to decompose and transform these wastes into by-products with high agronomic value is essential. The objective of this study was to determine the effect of sugary substances on the degradation of organic substrates to elaborate compost. The substances investigated were sugar, molasse and cane juice (Saccharum officinarum), mixed with an organic substrate composed of 30% manure, 50% corn pancake, 10% legume remains, 9% soil and 1% ash. The experimental design was completely random, with 16 experimental units, one absolute control and four repetitions. The variables evaluated were the following: days for decomposition, temperature, humidity, substrate weight and nutriment content. Molasses mixed with organic waste decreased the decomposition period by 6 days (9.68%), relative to the control (62 days). The treatment added with molasses showed the greatest temperature decline (8.7 °C), although no significant differences were found between treatments, at the beginning and end of the trial. The moisture content among treatments ranged from 56.5 to 59.0%, however, differences were not significant. The molasses treatment showed the greatest weight loss (10.8 kg) during the organic substrate degradation; however, there were no differences in pH and nutrient content (B, Ca, Cu, K, Mg, N, P, S, Zn, and MO). The treatment with the highest concentration of nutrients was the conformed by organic substances and molasses, thus, its use or integration is recommended to accelerate the degradation process in compost.</p> Ana Ruth Álvarez-Sánchez, Luis Tarquino Llerena-Ramos, Juan José Reyes-Pérez Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 30 Apr 2021 00:00:00 +0000 Effect of organic and inorganic sources of nutrition mixed with biofertilizers on melon fruit production and quality <p>The current demand for food means that large quantities of chemical fertilizers are used in horticultural production systems, leaving soils deteriorated with little fertility in the long term. Thus, the objective of this research was to evaluate organic and inorganic sources of nutrition combined with biofertilizers in their ability to provide nutritional elements to melon crop and in yield and quality responses compared to chemical fertilization. The evaluated treatments were T1 = 140 UNE; T2 = 120 UNE; T3 = 80 UNE+B; T4 = 60 UNE+B; T5 = 80 UNQ+B; T6 = 60 UNQ+B and T7 = 120-80-00 based on chemical fertilizer. A completely randomized blocks design with three repetitions was used, finding that T3 and T5 reduced the application of chemical fertilizer by 33% with respect to the recommended dose used in the Lagunera Region and improved yield by 11 and 9% respectively. Therefore, organic or chemical fertilizers mixed with biofertilizers can be a viable alternative to maintain and/or increase melon yield and reduce the use of chemical fertilizers in vegetable production systems at the same time.</p> Uriel González-Salas, Miguel Ángel Gallegos-Robles, Pablo Preciado-Rangel, Mario García-Carrillo, Martha Georgina Rodríguez-Hernández, José Luis García-Hernández, Tania Lizzeth Guzmán-Silos Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 30 Apr 2021 00:00:00 +0000 Relation between soil solution composition and petiole cellular extract of crops in western Mexico <p>Crop fertilization greatly impacts food production. However, insufficient applications can lead to poor yields. On the other hand, an excessive application leads to soil and aquifers pollution. In this paper, field studies were carried out to determine the ranges of mineral concentration and the interaction of the ions in the soil solution (SS) and the petiole cellular extract (PCE) in several cultures established in the states of Guanajuato, Colima and Jalisco, Mexico. The hypothesis states that there is a causal relationship between the mineral composition of the soil solution (SS) and the minerals and total soluble solids (TSS) in petiole cellular extract (PCE). The following cultures were studied in this research: avocado, blueberry, broccoli, cauliflower, raspberry, strawberry, lettuce, cantaloupe, papaya, and pepper. For each culture, PCE samples and SS samples using a press to break tissue and ceramic tip lysimeters were obtained. The results were processed to obtain ranges of variation within 50% of the closest values to the median. Correlations between the several ion concentrations were analyzed using analysis of variance. The results showed values (mg L-1) of NO3- (40-620), PO43- (17-66), K+ (3-377), Ca2+ (27-582), Na+ (15.3-500), Mg2+ (10-53), Fe3+ (0.6‑1.8), and Zn2+ (2.8-7.4) in soil solution, which allowed obtaining values of NO3- (27-9225), K+ (820-9375), Ca2+ (1.0-650), Na+ (25-620) and TSS (2-13 °Brix) in petiole cellular extract of petiole. Statistically significant correlations were observed between the concentrations of the SS ions regarding the concentrations in PCE in crops suggesting a relationship between the plant nutritive assimilation and cations or anions present in soil solution. The conclusion derived from this study is that ionic concentration ranges registered in the SS and in the PCE provide an approximation to the ranges of nutritional sufficiency for the horticultural crops established in the summer-winter in western Mexico.</p> Adalberto Benavides-Mendoza; Karim de Alba-Romenus, Nazario Francisco-Francisco Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 30 Apr 2021 00:00:00 +0000 Application of humic acids, chitosan and mycorrhizal fungus influence pepper growth and development <p>The application of biofertilizers and biostimulants influence numerous physiological crop responses, with which potentiated production can be achieved and crop quality improved. The use of these products can reduce synthetic fertilization besides improving plant tolerance to stress. Therefore, research was performed with the objective of evaluating the effect of chitosan, mycorrhizal fungi and humic acids on growth and development of pepper varieties under protected conditions. A completely randomized design with a 2 × 4 factorial arrangement was used with three replications, where the first factor was varieties (Magaly and Lycal) and the second one biostimulants: humic acids (1:30 v/v), chitosan (3 g L-1 of water) and mycorrhizal fungi (20 g of spores ml-1), and one control (control) for each variety (without bioactive application). The results showed that the three bioactive agents studied increased seed germination from 11.66 to 16.67% while emergence was enhanced by humic acids and chitosan. On the other hand, humic acids produced plants of higher height at 25 and 45 days after sowing (dap), and stems of higher diameter, which in turn increased seedling fresh and dry biomass (339.38 and 106.72 g). In the same way, they influenced fruit increase per plant (15.33 fruit), length, diameter and weight (12.22 cm, 43.33 mm and 92.22 g), which is why higher values were generated in the Magaly variety yield with 29.16 Mg ha-1. The Magaly variety significantly outperformed Lycal variety in terms of germination (96.67%), emergence (95%), plant height, and stem diameter (25 and 45 dap).</p> Juan José Reyes-Pérez, Marisol Rivero-Herrada, Arturo Enedicto Solórzano-Cedeño, Fernando de Jesús Carballo-Méndez, Gregorio Lucero-Vega, Francisco Higinio Ruiz-Espinoza Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 30 Apr 2021 00:00:00 +0000 Organic versus conventional fertilization on yield, morphological attributes and fruit quality of grape tomato in a non-recirculating subirrigation system <p>In the context of sustainable agriculture, the use of organic fertilizers is a viable option given the environmental impact caused by conventional fertilizers. The objective of this work was to evaluate the effect of organic fertilizers as a source of N on growth, yield, quality, and morphological traits in grape tomato fruits. Seven fertilization treatments were evaluated, which consisted of an inorganic nutrient solution (Steiner solution) and different mixtures of various OMRI certified nitrogen fertilizers of animal origin at a concentration ranging 100 to 120%. The results showed that T5 and T6 organic treatments showed a growth similar to the conventional treatment (T7). The SPAD index was 13.8% higher in organic treatments compared to T7 inorganic treatment. In the fruit production parameters, the T5 organic treatment was similar to the conventional treatment in the number of fruits per cluster, although in fresh fruit weight, yield, and longitudinal diameter, the conventional treatment surpassed the organic treatments by 21, 31.6, and 5.8%; whereas, the transverse diameter was similar in treatments T1 and T7. The fruit firmness was higher in T1 and T4 organic treatments, surpassing the inorganic treatment by 10.3 and 6%, respectively. Total soluble solids were higher in T4 organic treatment, surpassing the T7 inorganic treatment by 18%. The T7 inorganic treatment had higher values in most of the morphological attributes, although the effects were statistically similar to those of T3, T5, and T6.</p> José Antonio González-Fuentes, Carlos Javier Lozano-Cavazos, Pablo Preciado-Rangel, Enrique Troyo-Diéguez, Alfonso Rojas-Duarte, Juan Carlos Rodríguez-Ortiz Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 30 Apr 2021 00:00:00 +0000 Mineral content of landraces maize from Yucatán: analysis by µ-Fluorescence X-ray <p>In Yucatán, maize (Zea mays L.) is considered the main crop in the maize field, followed by squash, beans and pepper. Maize is found in the basic diet because of its contribution of active compounds, vitamins and essential minerals. Thus, the objective of this work is to characterize different maize landraces in terms of mineral composition cultivated in different regions of Yucatan for the selection of maize populations, which could have a potential use for biofortification and genetic improvement. Mineral analysis was performed by μ-X-Ray Fluorescence (μ-XRF, M4 Tornado 100) for the detection of macro- (P, K, S, Ca, Mg and Na) and micro-(Mn, Fe, Zn, Cu and Se) nutrients in 20 maize genotypes from five Yucatán regions (R1: Tixmehuac, R2: Chacsinkin, R3: Peto, R4: Motul and R5: Maní) of the races Nal t’eel (5), Ts´íit bakal (2), Xmejen-nal (5) and Xnuuk-nal (8). An analysis of variance of the quantified minerals was performed, together with Tukey’s comparison test and honestly significant difference. A dispersion in the total content of macronutrients and micronutrients in each genotype was established. With the average of minerals obtained, a principal component analysis (ACP) was performed. The results indicated significant differences (P ≤ 0.05) in mineral content among the maize genotypes. The mineral dispersion analysis showed that three genotypes of R2 and one of R3 exceeded their own content. The conglomerate analysis showed five groups with different characteristics in their coloration and region. The races Xnuuk-nal and Xmejen-nal cultivated in R2 had the highest mineral content with lilac, orange-red and orange coloration, which could be exploited for maize genetic improvement and biofortification.</p> Francisco Alberto, Carlos Juan Alvarado-López, Jairo Cristóbal-Alejo, Alejandra González-Moreno, Arturo Reyes-Ramírez Copyright (c) 2021 Terra Latinoamericana Fri, 23 Apr 2021 23:44:42 +0000 Field diagnostic techniques to determine nitrogen in maize <p>Few technologies are available to quantify crop's nutritional status during their vegetative cycle, such as in maize. Semiquantitative alternatives could replace the laboratory foliar analysis's classical approach for measuring nitrogen (N) in maize (Zea mays L.) in the field, although they require regional calibration against standard laboratory tests. In this work, we have calibrated four semi quantitative and two quantitative methods for diagnosing maize nutritional status in the El Bajio region, Guanajuato, Mexico. An experiment to test the effect of increasing N rates application on plant sap (cell extract) N was set up during the 2019 agricultural cycle. Five N treatments (0, 120, 240, 360, and 480 kg of N·ha-1) were tested, and each treatment was replicated five times. We have tested the following semi quantitative N methods: plant sap nitrate concentration (N-NO3) of the central midrib of the recently mature leaf (RML), plant sap N-NO3 of the base stem (in both cases measured by the ion selective method, using the portable LAQUAtwin® model NO3-11 nitrate ion meter, single-photon avalanche diode (SPAD) unit record, and the Normalized Difference Vegetation Index (NDVI). Additionally, a quantitative laboratory method for determining N-NO3 in the lower part of the maize plant's stem and total N in the RML was used. Data were acquired at different plant phenological stages: V7, V12, R1, and N-NO3 in the dry matter of the stem's base at R5. These results were correlated with the relative grain yield and those with a correlation coefficient (r) greater than 0.7 were accepted. Later, a critical concentration (CC) was estimated using an arithmetic-graphic technique for the crop to reach a relative yield of 90% for each method. The proposed CC results require further validation before being used in a commercial application. In synthesis, this work proposes a procedure for diagnosing N nutrition of maize in the field that might improve the current methods used for this purpose.</p> Eduhin Roacho-Cortés, Javier Z. Castellanos-Ramos, Jorge D. Etchevers-Barra Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 23 Apr 2021 23:54:03 +0000 Biochar effect, mycorrhizae and Guazuma ulmifolia, in early mining soil rehabilitation stages <p>Coal mining is one of the predominant activities in the department of Cesar, Colombia, and drives the country's economic growth. After the mineral extraction process, layers of collected soils and sterile material are usually used to form artificial soils, also called mining soils; these, due to their edaphic conditions, possess a certain toxicity and infertility degree, which restricts the growth and survival of organisms in the environment, leading to the formation of desert areas. Mining soil rehabilitation encourages the restoration of adequate conditions, allowing it to once more, offer some environmental goods and services. In this study, the objective was to evaluate the biochar, arbuscular mycorrhizal fungi (AMF) and NPK effect on the rehabilitation of mining soils, and on Guazuma ulmifolia seedling growth which were evaluated from three trials: initially a germination trial was carried out, using Guazuma ulmifolia seeds, mining soils and biochar in concentrations of 0, 1, 5 and 10%; Then, a nursery scale trial was established where four treatments containing the seedling, biochar, AMF and NPK were applied. Later, a field scale trial was carried out using four treatments with the seedling, biochar and AMF. Results show that biochar in concentrations of 1 and 5% significantly increased the germination percentage, leaf length and plant biomass; in addition, a 60% infection rate was found in plant roots by AMF; likewise, there was a significant increase in pH, phosphorus, organic carbon, glomalin and enzymatic activity in soils, also as well as a significant reduction in electrical conductivity. The use of biochar and mycorrhizae improved the properties of the soils and stimulated growth in the seedling, thus promoting the rehabilitation process.</p> Laura Janeth Quiroz-Mojica, María Margarita Daza-Mendoza, Luis Carlos Díaz-Muegue, Aslenis Emidia Melo-Rios, Gustavo Antonio Peñuela-Mesa Copyright (c) 2021 Terra Latinoamericana Thu, 15 Apr 2021 22:54:12 +0000 Sprouting induction in yam tubers (Dioscorea rotundata Poir) with the application of growth regulators <p>Natural dormancy of yam tubers can last several months, which makes storage mandatory in this crop before starting a new planting. This situation implies additional risks and costs for the farmers, which sometimes a forced to sow using tubers that have not yet completed their natural dormancy period. Consequently, irregular sprouting and uneven crops occur in the field. Therefore, the objective of this research was to evaluate the effect of applying plant growth regulators (PGR), such as thiourea, mepiquat chloride and ethephon on the induction of early sprouting of yam tubers in two varieties (cv. 0307‑49SB and 0307-50CB), harvested at 149, 179, 269 and 326 days after sowing (DAS). The results showed that growth regulators influence sprouting in tubers harvested at 179, 269, and 326 DAS, ethephon (1 g L‑1), being more effective in tubers of 179 DAS, thiourea (10-20 g L-1), those of 269 DAS, and mepiquat chloride (1-2 g L-1), in tubers of 326 DAS with similar effects on the two yam varieties. No effects of growth regulators were observed on sprouting in tubers of 149 DAS, which was attributed to immaturity of developing tissues. The study concludes that the application of growth regulators may induce early sprouting of yam tubers.</p> Diana Beatriz Sánchez-López, Lily Lorena Luna-Castellano, Sol Mara Regino-Hernández, Jorge Cadena-Torres Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Thu, 15 Apr 2021 23:05:41 +0000 Pumice, tezontle and nutritive solutions in cherry tomato crop <p>The use of low cost local mineral substrates and nutrient solutions with the suitable chemical composition may be the alternative to maximize the production potential of cherry tomato (Solanum lycopersicum L.). The objective of this study was to evaluate substrates from the area of the State of Nayarit, Mexico in combination with nutritional solutions, on growth, nutritional content and cherry tomato production. The experimental design was completely randomized with two-factor arrangement. The factors were pumice and tezontle substrates and Steiner and Castellanos nutrient solutions, which originated four treatments with 11 repetitions where one of them was a plant with two stems. The variables plant height, stem diameter, leaf area, dry aerial part biomass, dry root biomass, fruit production per plant, soil plant analysis development (SPAD) units and leaf nutrient content (N, P and K) were determined. The results showed that Steiner nutritive solution increased fruit production and also growth evaluated in plant height, stem diameter and dry root biomass. The nutritional content of N, P and K was higher with Castellanos solution. In the pumice substrate, fruit production, plant growth and nutrient content were higher in relation to tezontle plants. The study concluded that pumice substrate in combination with Steiner nutritive solution was the most viable for cherry tomato, since it favored plant growth and fruit production.</p> Jonás Alán Luna-Fletes, Elia Cruz-Crespo, Álvaro Can-Chulim Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Wed, 31 Mar 2021 04:14:32 +0000 Fertility and soil quality index of the San Pedro river basin in Nayarit <p>The agricultural area of the San Pedro River basin in Nayarit is a coastal plain with alluvial soils, subjected to flooding, deposition and different processes that control nutrient input and soil fertility. The objective of this investigation was to evaluate soil properties to diagnose fertility and determine the soil quality index considering the parameters pH, MO, N, P, K, CIC, Ca and Mg. Samples were carried out at 30 cm in depth in 38 sites in June 2017 and 45 in 2018; pH, EC, texture, Da, CO, MO, inorganic N, P, CIC and interchangeable bases were measured. The mean, maximum and minimum values were pH 5.78, 8.15 and 3.28; MO 1.58, 3.02 and 0.65%; inorganic N 22.5, 43.6 and 3.5 mg kg‑1; P Olsen 32.5, 67.4 and 1.4 mg kg‑1; K 0.45, 0.80 and 0.10 cmolc kg-1, respectively. The average EC was 1.39 dS m-1 and indicate that no salinity problems existed; 73% of the sites were from sandy to loamy texture. The Soil Quality Index (SQI) indicated that the basin had a medium fertility level; average SQI was 0.64; 17% of the sites had low fertility with pH from 3.28‑5.40, MO 0.81-1.20%, N 10-20 and P 5-10 mg kg‑1; 42% medium, pH 6.41-7.30, MO 2.01‑2.50, N 40-60 and P 15-20 mg kg-1; 36% moderately high, and 5% high with pH 8.20-8.80, MO 3.01-4.00, N 100-150 and P 25‑35 mg kg-1. The SQI distribution showed that in the upper plain, soils were from low to medium fertility; in the intermediate and low plains from medium to high fertility, and in lower elevation parts, fertility was limited by the interaction between the continental and marine systems that salinize soils.</p> Óscar Germán Martínez-Rodríguez, Álvaro Can-Chulim, Héctor Manuel Ortega-Escobar, José Irán Bojórquez-Serrano, Elia Cruz-Crespo, Juan Diego García-Paredes, Alberto Madueño-Molina Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Wed, 31 Mar 2021 03:59:35 +0000 Estimation of fractional vegetation cover and canopy nitrogen content in corn by remote sensing <p>Nitrogen use efficiency of nitrogen use in agriculture is very low, causing environmental problems and low crop productivity, therefore, knowing the spatial and temporal distribution of biophysical variables such as the fractional vegetation cover (FVC) and the canopy nitrogen content (CNC) of the crops will provide valuable information to improve this condition. The use of freely accessible satellite imagery, such as Sentinel-2 (S-2) images, can facilitate this task. Due to the above, a study was carried out in six corn plots grown by producers in Texcoco de Mora, Estado de Mexico. The first objective was to investigate the relationship between spectral indices, estimated from the reflectance measured with a multispectral radiometer at surface level and S-2 images, with FVC, estimated by digital photographs through the Canopeo mobile application. The second objective was to obtain a linear model that estimated the CNC from the analysis of different spectral indices. Two models were generated to estimate FVC, from the radiometric information at surface level, their validation yielded a high value of R2 = 0.92 and a RMSE = 7.3% between measured and estimated FVC data; however, in the case of the data estimated with S-2 images, lower values of R2 = 0.67 and RMSE = 17.6% were obtained, which was attributed to a possible effect of the atmosphere, since the study period coincided with the rainy season. Finally, to estimate the CNC, the best results were obtained with the model generated from ClGreen, in which an R2 of 0.91 and a RMSE of 0.63 g m-2 were obtained, when comparing the CNC measured in relation to the estimate.</p> José Manuel Salvador-Castillo , Martín Alejandro Bolaños-González, Enrique Palacios-Vélez, Luis Alberto Palacios-Sánchez, Adolfo López-Pérez, José Miguel Muñoz-Pérez Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Wed, 31 Mar 2021 04:09:29 +0000 Patterns for estimating soil fertility using Pfeiffer´s chromatography technique <p>Pfeiffer´s chromatography is based on paper chromatography principles, which could be considered as a useful and cheap alternative for estimating the soil fertility. However, there is a lag in the interpretation of the resulting chromatograms, entangling their use. The objective of this study was to generate prediction models for interpreting the chromatograms obtained from Pfeiffer´s chromatography technique. Physical, chemical, and biological characteristics of soil samples from an apple tree orchard with different agronomic management were evaluated by means of Pfeiffer chromatography and conventional laboratory analyzes. The results were statistically correlated for obtaining the components of the chromatogram with the highest interaction to estimate soil fertility. Eventually, through regression models, numerical patterns were established to estimate and interpret the contents of available P, K+, Cu2+ and organic matter, as well as the categorization to find trends for sand contents, Ca2+, Mg2+, Fe2+, Mn2+ and Zn2+. Results show that, under the conditions in which this research was conducted, the soil fertility can be estimated through Pfeiffer´s chromatography, and that the patterns generated in this study contribute to its interpretation.</p> Adriana Hernández-Rodríguez, Brisany Ochoa-Rodríguez, Dámaris Ojeda-Barrios, Jorge Jiménez-Castro, Rocío Sánchez-Rosales, María Janeth Rodríguez-Roque, Esteban Sánchez-Chávez Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Wed, 24 Mar 2021 18:52:08 +0000 Ethnoedaphological study of land use types associated with productive chains in the Ejido Santa Cruz Durango <p>The signing of the Treaty Mexico-United States-Canada (T-MEC) is intended to improve regional productive chains to promote the creation of a high number of merchandise and build economies of greater scale. However, on a regional scale, the productive chains have limitations, for example, not appreciating the structure in detail, capacities or articulations between them, which are key to taking the product from its origin to the final market. Ethnoedaphology analyses in a holistic and detailed way the knowledge that producers have of their lands. Therefore, the objective of this research is to determine the types of land use related to agricultural production chains through an ethnoedaphological study. This investigation was performed in the common land Ejido Santa Cruz de Guadalupe, Nombre de Dios, Durango. The producers were interviewed about their lands, management, yields and knowledge of productive chains. For each soil class, a modal profile and its edaphic properties were determined in the field and laboratory for its characterization and scientif ic classif ication with the World Reference Base (WRB). The producers recognized 14 land types, which were integrated into f ive reference groups (Kastañozems, Phaeozems, Calcisols, Solonetz and Regosols). The ejido has 48 types of land use that are described by the variables of major use (livestock, dry farming and irrigation); type of producer (owner or lessee); types of tillage (conventional, vertical or a combination of both); cropping system (mono- and polyculture and crop rotation), and the product obtained. In the ejido 11 crops are managed, of which only maize-silo and barley correspond to 100% of the productive chains, leaving aside other products such as beans and alfalfa. The ethnoedaphological study allows integrating knowledge from the beginning of production through the different types of land use to the f inal market, identifying in detail all the articulations of the productive chains of the study area.</p> Iris del Carmen Morales-Espinoza, Carlos Alberto Ortiz-Solorio, Ma. Del Carmen Gutiérrez-Castorena, Edgar Vladimir Gutiérrez-Castorena Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 12 Mar 2021 22:42:39 +0000 Fodder productivity in corn hybrids under different plant densities and fertilization rates <p>Fertilization and plant density are some essential technological components in modern agriculture. The aims of this research was to define the effect of plant density and fertilization rates on fodder productivity of three commercial corn hybrids. In the spring-summer 2017 season, an experiment was established in the Cotaxtla Experimental Field of the National Institute for Forestry, Agriculture and Livestock Research (INIFAP in Spanish), under a completely randomized block design arranged in subdivided plots with three replicates. Three factors were studied, fertilization rates (207-69-60 and 253-69-60), corn hybrids (H-564C, H-567 and HE-3B) and plant densities (62 500, 83 000 and 100 000 plants ha-1). During the study period, the accumulated monthly precipitation was 1003.6 mm and average temperature was 26.7 °C; the maximum temperature occurred in August (28.7 °C) and the minimum in November (25.3 °C) 2017. Duncan’s test (P ≤ 0.05) showed that the fertilization rates integrated by the formula 253‑69‑60 increased green fodder yield, 15.06% more than in the formula 207-69-60. Hybrids H-564C and HE-3B expressed the best green fodder yields with 53 105 and 51 937 kg ha-1, respectively. Increasing plant density (62 500 to 100 000 plants&nbsp;ha‑1) and green fodder yield when high units of N were applied (253-69-60). Likewise, the increase in plant density did not affect the agronomic characteristics of the evaluated hybrids. The commercial H-564C hybrid expressed the highest green and dry fodder yields, followed by the experimental HE-3B hybrid. This last material is a candidate to be released and commercialized for fodder purposes in the tropical area of the state of Veracruz.</p> Flavio Antonio Rodríguez-Montalvo, Mauro Sierra-Macías, Alejandro Espinosa-Calderón, Marcos Ventura Vázquez-Hernández, Sabel Barrón-Freyre, Pablo Andrés-Meza, José Luis Del Rosario-Arellano Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 12 Mar 2021 22:55:40 +0000 Groundwater quality for agricultural use in Zacoalco de Torres and Autlan de Navarro, Mexico <p>In Mexico, one of the main sources of agricultural&nbsp;irrigation supply is groundwater, irrigating approximately two million hectares of land and also&nbsp;providing 75% of water volume in rural and urban areas nationwide. However, these water resources have been largely affected by pollutants from industrial waste, as well as leaching of chemical substances in agricultural soils. To assess the physicochemical characteristics of groundwater, this study was performed in Zacoalco de Torres and Autlan de Navarro, which are located in areas of the agricultural valley and thus influenced by agricultural and urban activities. Samples were collected in the dry and rainy seasons in 2017. The sampling sites were deep wells and water wheels. In total 48 samples were obtained corresponding to the two stations. In each sample, the following parameters were analyzed: pH, anions and cations, electric conductivity (EC), residual sodium carbonate (RSC), sodium adsorption ratio (SAR), as well as hydrogeochemical classif ication. The underground waters of Zacoalco are mostly chlorinated-magnesium waters and in Autlan bicarbonate-magnesium with medium and low concentrations, so they are recommended for irrigation; with respect to salinity Zacoalco has 40% high salinity waters in dry and 66% medium salinity waters in rains; Autlan has 75% high salinity waters in dry and 75% medium salinity waters, so its use shows moderate restrictions.</p> Oscar Raúl Mancilla-Villa, Blanca Noemy Anzaldo-Cortes , Rubén Darío Guevara‑Gutiérrez, Omar Hernández-Vargas, Carlos Palomera-García , Yerena Figueroa-González , Héctor Manuel Ortega-Escobar , Héctor Flores-Magdaleno, Álvaro Can-Chulim, Elia Cruz-Crespo, Edgar Iván Sánchez-Bernal , José Luis Olguín-López, Isabel Mendoza-Saldivar Copyright (c) 2021 Terra Latinoamericana Fri, 12 Mar 2021 23:13:42 +0000 Changes in restored soils subject to weathering and their implication in Mexican environmental regulations <p>An overview of current Mexican legislation regarding soil restoration and updating needs is made through the analysis of three case studies located in the southeastern México: a) soil affected by spillage of congenital waters (Zone 1), b) soil contaminated by hydrocarbons (Zone 2) and, c) a site adjacent to urban infrastructure (Zone 3). It was performed a comparative analysis of the soils conditions in the short and long term after the anthropogenic impact and restoration process that were carried out in each studied location. It was found that important properties of the soils do not recover after the weathering process, for instance in Zone 1, DR and DA as well as %Po did not reach equivalent values to the control sample and the soil texture is different even after a long recovery period. For Zone 2, it was detected important variations in the concentration of Ca, Na and K in both the impacted and recovered soils which affect the growth of plantations. In Zone 3, there were found signif icative differences in DA, %Po; %L, %R, %MO and CEC parameters. The current normative considers general aspects, but does not contemplate the actual site situation, there is an information gap due to this, although it was observed achievement of physical and chemical properties for the&nbsp;recovery soil use in each site, it was also noticed that the evaluations do not consider if these properties can change over time due to weather conditions, therefore, they could influence the success of each restoration process in the long term. The information generated can be used to make decisions about government rescue programs for the primary sector or as a starting point in the implementation of Environmental Bases Lines (LBA) for the hydrocarbon sector.</p> José del C. Méndez-Moreno, Iliana M. De la Garza-Rodríguez, Sonia A. Torres-Sánchez, Nelly del C. Jiménez-Pérez, Irma Sánchez-Lombardo, Sugey López-Martínez, Carlos E. Lobato-García, Carlos M. Morales-Bautista Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 12 Feb 2021 23:48:45 +0000 Effect of imbibition treatments on the germination of Stenocereus zopilotensis (Cactaceae) native from Guerrero, Mexico <p>The prickly pear cactus “tuna pelona” (Stenocereus zopilotensis), is an endemic cactus species from the state of Guerrero, Mexico, it develops in semi-arid areas and has great ecological importance as it houses and forms part of the diet of multiple species in its niche. There is a constant threat to natural populations of this species due to the overexploitation of seedling collections in the f ield by unregulated trade. In order to design an alternative for the conservation management of these species, the objective of the work was to evaluate treatments for the imbibition of “hairless tuna” seeds to promote germination and the successful establishment of seedlings with economic technologies for the farmers of the area. Fruits of "tuna pelona" (S.&nbsp;zopilotensis) were collected, near the community of Xalitla, municipality of Tepecoacuilco de Trujano, Guerrero; the seeds were stored for 70 and 273 days after collection (dac) at room temperature in order to maintain adequate conditions for the conservation of&nbsp;viability until reaching dormancy. In the stored seeds, the effect of soaking treatments was evaluated: 0, 6, 12, 24 and 12 hours in water plus another treatment that consisted of immersion in a plant-based hormonal stimulant. The germination percentage per treatment was evaluated, it was found that the control treatment (zero hours in water) of seeds stored at 70 dac only obtained 2.4% of germination. The treatment of soaking in water and in the hormonal stimulant both for 6 h presented the highest germination values with 48.6 and 44.4% respectively when using seeds of 273&nbsp;dac at 14 days after the application of the treatments. These results will allow the massive production of seedlings of the species for reforestation and regional marketing purposes.</p> Abraham Monteon-Ojeda, Betsabe Piedragil-Ocampo, Paul García-Escamilla, Yuridia Durán-Trujillo, Teolincacihuatl Romero-Rosales Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Fri, 12 Feb 2021 23:57:51 +0000 Effect of seed treatment with QuitoMax® on the yield and quality of ESEN and L-43 varieties of tomato seedlings <p>The research work was developed in the basic unit of cooperative production UBPC "Antonio Maceo Grajales" during the 2017-2018 and 2018‑2019 seasons, on a Fluvisol soil, with the objective of evaluating the influence of the QuitoMax® on the seedlings obtained in tomato seedbeds. Two experiments were carried out, in the 2017-2018 season the variety ESEN was evaluated and in the season 2018-2019 the variety L-43, the seeds were soaked in a solution of QuitoMax®, with a concentration of 1 g L-1 during the four hours prior to sowing. Ten polyurethane trays were used for the treated seeds (T1) and another 10 with untreated seeds (T2). At the time of transplantation, the following parameters were evaluated: Plant height (cm), stem thickness (mm), number of leaves, root length (cm) and fresh mass (g). For the statistical analysis of the data from the seedbed, a t-student test was used for a 5% of probability of error, with the statistical package STATISTICA version 8. The results demonstrated the positive incidence of the QuitoMax® about the quality of the seedlings in both varieties.</p> Luis Gustavo-González, Irisneisy Paz-Martínez, Tony Boicet-Fabré, María Caridad Jiménez-Arteaga, Alejandro Falcón-Rodriguez, Tomás Rivas-García Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sat, 13 Feb 2021 00:04:51 +0000 Development and production of cabbage (Brassica oleracea var. Royal vantage) under different osmotic pressures and biofertilized with bacterial consortia <p>The development and production of cabbage (Brassica oleracea var. Royal vantage) in a greenhouse, under different osmotic pressures of the Steiner nutrient solution and biofertlized with bacterial consortiums, were evaluated. A 4 × 3 factorial design was established, where the factors were four levels of osmotic pressure (0.18, 0.36, 0.54 atm and a control without nutrient solution), and two bacterial consortia: Azospirillum brasilense + Acinetobacter calcoaceticus (AA) and Raoultella terrigena + Chromobacterium violaceum (RC), and an uninoculated control. Six repetitions were established for each treatment. Seeds inoculated with the consortium AA had the highest emergence percentage (100%), as well as the highest emergence rate (20.5), compared with the consortium RC and the non-inoculated plants. Inoculation with the consortium AA and the osmotic pressure of 0.54&nbsp;atm produced taller plants (60-65%), and a stem with a larger diameter (35-46%). The weight of the fresh biomass and the accumulation of dry material doubled in the inoculated plants compared to the non-inoculated ones. A higher concentration of K was observed in plants inoculated with AA and RC (20‑35% and 25-45%, respectively) compared to non-inoculated plants. The nitrate concentration in the plants increased between 200-350% and 60-230% with the inoculation of consortia AA and RC, respectively. The P concentration increased between 200-500% with the consortium AA and between 100-400% with the consortium RC. Inoculation with the consortia AA and RC, at osmotic pressure of 0.54 atm, induced the greatest development of the cabbage heads (classif ied as 5 and 4, respectively). It is concluded that cabbage, under moderate mineral fertilization in a greenhouse, responds favorably to the inoculation of plant growth promoting bacteria.</p> Iris Margarita Aguilar-Flores, David Espinosa-Victoria, Moisés Carcaño-Montiel, María de las Nieves Rodríguez-Mendoza Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sat, 13 Feb 2021 00:18:34 +0000 Diversity of arbuscular mycorrhizal fungi associated with field-grown zucchini pumpkin (Cucurbita pepo L.) using plastic padding <p>Microbial communities have effects on crop growth and productivity. However, these communities can be affected by various agricultural practices. The aim of this work was to determine the diversity of arbuscular mycorrhizal fungi (AMF) associated with the cultivation of zucchini pumpkin established in the f ield under plastic padding. The abundance, richness and index of mycorrhizal diversity in the padded cultivation of zucchini pumpkin were evaluated under three colors (white, black and red) of padding plastic during the summer-fall (S‑F) and winter-spring (W‑S) cycles established with the following treatments: C (control), V (vermicompost), WPP (white plastic padding), WPP+V, RPP (red plastic padding), RPP+V, BPP (black plastic padding) and BPP+V. A randomized experimental block design with 10 replicates was used. The ANOVA showed signif icant differences (P&nbsp;≤ 0.05) in mycorrhizal colonization, abundance and diversity index in both culture cycles. In addition, 21 morphospecies were identif ied in S-A and 12 in W-S. The BPP affected the AMF in all the variables evaluated. Seasonality conditioned mycorrhizal colonization, and the black padding affected the endophyte-host symbiosis, in addition to affecting the mycorrhization, abundance, richness and diversity index of AMF. Knowledge on the diversity of AMFs is important to select the morphospecies with potential as biofertilizers.</p> Liliana Lara-Capistrán, Ramón Zulueta-Rodríguez, Juan José Reyes-Pérez, Bernardo Murillo-Amador, José Leonardo Ledea-Rodríguez, Luis Guillermo Hernández-Montiel Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sat, 13 Feb 2021 00:36:10 +0000 Economic value of water in the Alfajayucan (100) district of irrigation, Hidalgo <p>Water for human consumption is supplied for different demanded uses: domestic, agriculture and industry. According to what has been reported by FAO and UNESCO, agriculture consumes 69% of water; domestic purposes consume 10% and industry 21%. Given the importance of water in agriculture and crop pattern, knowledge on the optimal allocation and economic value of the resource is required. The objective of our study was to obtain an optimal crop pattern in the Irrigation District 100 (ID 100) Alfajayucan Hidalgo, as well as to estimate the economical price of water under different scenarios. The hypothesis states that the fees paid by farmers in ID 100 do not reflect their true scarcity value. A&nbsp;linear programming model was implemented to maximize the net income of farmers with 17 cyclical and perennial agricultural activities, subject to 57 surface restrictions, water, labor and machinery. The results indicate that the net income of ID 100 would increase by $273 million if the optimal crop pattern is established, compared to that obtained in the 2015‑2016 agricultural cycle. The economical price of the water according to the model was $1.44&nbsp;m-3, much higher than that currently paid (irrigation fees = $0.02&nbsp;m-3), conf irming the existence of a strong subsidy to the water supply. Thus, in light our results, the water fees paid by farmers should increase.</p> Domingo Martínez-Luna, José S. Mora-Flores , Adolfo A. Exebio-García, Oscar A. Arana-Coronado, Enrique Arjona-Suárez Copyright (c) 2021 JOURNAL TERRA LATINOAMERICANA Sat, 13 Feb 2021 00:37:43 +0000 Actinobacteria from avocado rhizosphere: antagonistic activity against Colletotrichum gloeosporioides and Xanthomonas sp. <p>Actinobacteria from the rhizosphere of agricultural crops are a potential source of antagonists against phytopathogenic microorganisms. Thus, the objective of this study was to characterize the antagonistic activity in vitro of actinobacteria from the rhizosphere of avocado trees (Persea americana) against Colletotrichum gloeosporioides and Xanthomonas sp. Actinobacteria were isolated from rhizosphere soil samples of avocado trees var. Hass collected from an orchard from Ziracuaretiro, Michoacán. The isolated strains were assessed against C. gloeosporioides and Xanthomonas sp. by means of in vitro confrontation tests. The antagonistic activity was determined by measuring the radius and diameter of the growth inhibition zone of C.&nbsp;gloeosporioides and Xanthomonas sp., respectively. A total of 41 actinobacterial strains were isolated, of which 44% inhibited growth of at least one of the two plant pathogens. Specif ically, 15% of the isolates inhibited growth of C. gloeosporioides, 22% of Xanthomonas sp. and 7% of both phytopathogens. The mycelial growth inhibition radius of C. gloeosporioides fluctuated from 6.6 to 15.5&nbsp;mm, while in Xanthomonas&nbsp;sp., the inhibition zone was from 15.5 to 62.7 mm. These results indicated the importance of rhizosphere actinobacteria as antagonists of phytopathogenic microorganisms, some of which could be used as potential biological control agents against anthracnose and bacterial leaf spot.</p> Jesús Rafael Trinidad-Cruz, Gabriel Rincón-Enríquez, Zahaed Evangelista-Martínez, Cecilia Guízar-González, Jhony Navat Enríquez-Vara, Luis López-Pérez, Evangelina Esmeralda Quiñones-Aguilar Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Mon, 18 Jan 2021 00:00:00 +0000 Tolerance to heavy metals of plants from arid zones <p>In Mexico, arid areas represent more than half of the territory where erosion is due to pollution, so the level of tolerance of representative plant species should be studied to restore or reforest. This study evaluated six species from arid zones – Agave funkiana, A. obscura, A. salmiana of the Asparagaceae family and Opuntia cochenillifera, O. ficus-indica, Pereskia sacharosa of the Cactaceae family. The plants were propagated in vitro to obtain shoots that were established at different cadmium (Cd2+) and lead (Pb2+) concentrations during the rooting stage to determine their tolerance. The Probit Analysis was used to calculate the mean lethal concentration (LC50) at the different doses, which produced different effects in the six species of arid zone plants evaluated in this investigation. The species A. salmiana and P. sacharosa obtained a mortality of 55% with 0.009 mM of Cd and 77% with 0.8 mM for Pb. These concentrations were the highest. Thus, ecotoxicological bioassays are useful for evaluating contaminants, such as heavy metals in tolerant plants as A. obscura, O. cochenillifera, and O. ficus-indica.</p> Lucila Perales-Aguilar, José Antonio Esquivel-Rivera, Héctor Silos-Espino, José Cruz Carrillo-Rodríguez, Catarino Perales-Segovia Copyright (c) 2021 Terra Latinoamericana Sun, 17 Jan 2021 20:37:13 +0000 Agronomic response of two tomato varieties (Solanum lycopersicum L.) to the application of the biostimulant whit chitosan <p>Chitosan has properties that promote growth and nutrition of crops. It is a biostimulant that in previous studies it demonstrated activity as growth regulator, germination and vigor promoter of plants, and yield increaser. In this work, it was evaluated the individual or combined effect of the application of chitosan by seed imbibition and foliar administration at the beginning of flowering on the agronomic response (growth, development and yield) of two varieties ESEN and L-43, established in f ield conditions with a block design at random with three replicates. The results show that the combined treatment of chitosan on the seeds in doses of 1 g L-1 and at the beginning of flowering in doses of 300&nbsp;mg ha-1 promotes the evaluated variables associated with yield, and increasing this up to 60.9&nbsp;Mg&nbsp;ha-1 in the ESEN variety and up to 27 Mg&nbsp;ha-1 in the L-43 variety, which represents an increment of 28.5 and 25% respectively, in comparison with the control treatment. It is concluded that the biostimulant chitosan applied as combined treatment during seed imbibition and foliar via at the beginning of flowering has signif icant results improving the variable number of flowers for plants, number of fruits, mass of the fruits and yield for both varieties in comparison with the treatment control, being obtained yield among 47‑60.9&nbsp;Mg ha-1 when applying chitosan for single 42‑43 Mg ha-1 in the treatment control.</p> Tomás Rivas-García, Luis Gustavo Gonzalez-Gomez, Tony Boicet-Fabré, María Caridad Jiménez-Arteaga, Alejandro Bernardo Falcón-Rodríguez, Julio César Terrero-Soler Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sun, 17 Jan 2021 20:43:41 +0000 Land use change model in Carmen-Pajonal-Machona lagoon system, Mexico <p>Change in land use is a dominant process with negative effects on the structure and functioning of ecosystems. The coastal area of Tabasco is very important for economic development because of the large coastal wetland areas that flow into the Gulf of Mexico. However, coastal wetlands are strongly altered by the change in land use due to their proximity to urban areas, oil extraction and agricultural activities. They are also severely threatened by climate change and sea level rise. This study analyzed the change in land use in Carmen-Pajonal-Machona lagoon system on Tabasco coast through Land Change Modeler during 2000-2015. A probabilistic-spatial scenario was generated in 2030 through Markov Chains and Cellular Automata, detecting that secondary vegetation, wetlands, and acahuales altogether decreased 14 238&nbsp;hectares from 2000-2015. These changes have affected the reduction of coastal habitats and lead to high flood risks for the population in this area. Additionally the 2030 projection shows alarming values because the ecosystems reflect a loss of 8090 hectares if no change in favor is performed in the paradigm of coastal soil management. Therefore, future trends in land use change on the coast of Tabasco can be mitigated through the implementation of sustainable development policies that involve short- and medium-term planning of the establishment of Territorial Planning programs and the creation of Protected Natural Areas.</p> Rodimiro Ramos-Reyes, Miguel Ángel Palomeque-De la Cruz, Hector Javier Megia-Vera, Daniel Pascual-Landeros Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sun, 17 Jan 2021 20:50:21 +0000 Impact of climate change on potential evapotranspiration and growing season in Mexico <p>Potential evapotranspiration (PET) and length of growth period (LGP) are essential indicators of agricultural planning. National and local agendas should consider climate change scenarios and its impact on evapotranspiration. Therefore, the objective of this study was to analyze spatial distribution of PET and LGP in current climate conditions throughout the country, and under a climate change scenario to have suff icient technical elements for recommending adaptation actions for agricultural national production. The monthly PET was estimated from the reference PET (ET0) by the Penman-Monteith method using parameter and monthly average rainfall (R), start and end date, and length of growing period were evaluated. Once this was done, 28 climate change scenarios were studied to def ine the alteration of PET and its effect on LGP in the agricultural areas of the country. PET is expected to increase practically throughout the national territory as a consequence of the general increase in temperature and the decrease in relative humidity. PET classes smaller than 1000 mm per year may decrease, while those greater than 1000 mm may increase on average 20% around the years 2040-2069, and almost 50% towards 2070-2099. When climate change in LGP was considered for each state, three of them (Baja California Sur, Coahuila, and San Luís Potosí) were considered to experience no change concerning current conditions. In the rest of states, the LGP may decrease due to a combination of changes at the beginning and end of the growing period. Cartographic studies allow spatial analysis of the results, which should be integrated into the planning of agricultural water use. At the same time, they make it possible to advance in the design of measures to adapt for climate change with a solid technical support.</p> Alejandro Ismael Monterroso-Rivas, Jesús David Gómez-Díaz Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sun, 17 Jan 2021 21:01:01 +0000 In vitro establishment of the nematophagous fungus Pochonia chlamydosporia var. catenulata in different soils <p>The edaphic conditions present in agroecosystems can influence the establishment and effectiveness of a microbial control agent for nematodes. For this reason, the objective of the present investigation was proposed to evaluate the in vitro establishment of Pochonia chlamydosporia var. catenulata in Cuban agricultural soils of the Ferralitic, Fluvisol and Brown type. For this, three types of soils were analyzed using the soil membrane technique, evaluating in each one of them the native microbial populations, the mycelial growth and the relative growth of the nematopophagous fungus of interest. A completely randomized design was used and the statistical processing of the data obtained was performed using a factorial ANOVA and linear regression. The results showed that P. chlamydosporia var. catenulata grew and produced chlamydospores in all the edaphic conditions evaluated, however, the greatest growth was registered in Fluvisol and Ferralitic soils compared to Pardo. This suggested that the higher native microbial populations and the acid pH present in the Brown soil, could affect the growth of this fungus. The results obtained conf irm that the nematophagous fungal species P. chlamydosporia var. catenulata has adaptability, persistence and multiplication capacity in different soils and its use is suggested in Fluvisol, Ferralitic and Brown soils, provided they do not present an acid pH ≤ 4.17.</p> Wilson Geobel Ceiro-Catasus, Maité Hidalgo-Viltres, Leopoldo Hidalgo-Díaz, Jersys Arévalo-Ortega, Milagro García-Bernal, José Manuel Mazón-Suástegui Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sun, 17 Jan 2021 21:01:52 +0000 Soil quality evaluation: generation and interpretation of indicators <p>Soil management practices alter its properties, especially when the energy inputs to the soil-plant system are less than the outputs, or its resilience is unable to return it to the state prior to the intervention. When the disturbances approach the tolerance limits of the soil system, factors that limit production appear. Changes can be established using quality indicators and indices. These show the direction of change over time. The objective of this work was to evaluate the current soil quality in four agricultural ejidos of Tepeaca, Puebla, Mexico, which have centuries of dedication to agricultural production. The history, the most common cropping patterns and the dominant land classes, defined with the participation of local producers, were investigated. Physical, chemical and biological properties of soils subjected to different management were analyzed and quality indicators were defined. The&nbsp;selection criteria for the sampling sites were the most frequent cultivation patterns as follows: (i) cut flower, (ii) continuous vegetables, and (iii) vegetables with resting period during the season with no rain. The same soils were used without management as reference. The properties selected as indicators were the following: pH, electrical conductivity, soil organic matter, wet aggregate stability, Olsen extractable phosphorus, DTPA extractable iron, and earthworm density. The first four were sensitive to differentiate between undisturbed (uncultivated) soils from cultivated soils. The last four were selected by showing rates of change according to cropping patterns, which indicates the need to promote agronomic management strategies. With these properties, a soil quality index was built that allows to establish the direction of change that soil quality will experience when modifying one or more indicators.</p> Ximena Castillo-Valdez, Jorge Dionisio Etchevers-Barra, Claudia María Isabel Hidalgo-Moreno, Arturo Aguirre-Gómez Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sun, 17 Jan 2021 21:02:38 +0000 Evaluation of the yield, morphological and chemicals characteristics of varieties of purple corn (Zea mays L.) in the region Cajamarca-Peru <p>Peru has a great diversity of agricultural products due to the variety of climates and geographical diversity, hence it accounts with seven main races of purple corn. Therefore, the objective of our research was to evaluate the yield, and the morphological and chemical characteristics of five varieties of purple corn, which were the following: INIA-601, MMM improved purple corn (experimental variety), UNC‑47, INIA‑615, and PM-581, plus Canteño race, which was used as control. The study was conducted at two altitudinal levels, 2770 m (Llollon) and 3140 m (Llanupacha), both belonging to the District of Ichocan, Province of San Marcos and Region Cajamarca in Peru, during 2017/18 and 2018/19 agricultural campaigns. The agronomic variables and anthocyanin content were evaluated. The results show that the best yield on average was for INIA-601, with 5.3 Mg ha-1 in Llanupacha and with 4.5 Mg ha-1 in Llollon. The varieties with the highest height of the plant and ear were MMM (2.33 and 1.2&nbsp;m) and INIA-601 (2.35 and 1.25 m) in Llollon; whereas in Llanupacha, MMM (1.93 and 0.88 m) and INIA-601 (1.9 and 0.88 m), respectively, obtained the highest values. The INIA-615 variety showed the earliest flowering for females and males in both altitudinal levels, at days101.5 and 93.3 in Llollon and at days 125.6 and 118.3 in Llanupacha, respectively. In addition, this variety obtained the lowest percentage of rot in Llanupacha (2.3%) and in Llollon (5.9%). In addition, the INIA-601 variety was highlighted for having the highest quantity of anthocyanins in both the ear and bracts, presenting (6.7 and 7.5 mg g-1) and (2.9 and 2.5 mg g-1), in Llanupacha and Llollon, respectively.</p> Melissa Rabanal-Atalaya , Alicia Medina-Hoyos Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sun, 17 Jan 2021 21:03:42 +0000 Nitrous oxide (N2O) measurements in managed soil under grazing with dairy cattle <p>Nitrous oxide (N2O) emissions measurements in livestock systems in the Dominican Republic are a priority for its government. The N2O has been responsible for 5% of total GHG (greenhouse gas) in the last 100 years. In Dominican livestock, various nitrogen fertilizers and amendments are used to increase the productivity these systems. However, if these fertilizers are not properly managed, these could generate N2O emissions. Therefore, our research was carried out with the aim of quantifying N2O emissions from grazing forage with dairy cattle. A Bermuda grass pasture (Cynodon dactylon) from Casa de Alto, Dominican Republic was used. The study was conducted during the period of June – August, 2018. A completely randomized sub-divided plot design was used with three factors, four repetitions and three treatments (urine, urea, and control). Closed-flow PVC chambers were used to obtain gas samples and determine N2O emissions. In addition, climatic factors, nitrogen (N) in urine, soil and grass were recorded. Data were analyzed with the InfoStat statistical software. The N2O emissions averaged the following values: 0.56 mg L-1 for control, 1.02 mg L-1 for urine and 1.18 mg L-1 for urea. The only treatment that showed statistical differences with the control (P&nbsp;&lt;&nbsp;0.05) was urea. Emissions were 5.6, 10.2 and 11.8&nbsp;kg ha-1 for the control, urine and urea, respectively, with high emissions compared to results obtained in other research in the country.</p> Pedro Antonio Núñez-Ramos, Gregorio García-Lagombra, Joaquín Caridad del Rosario, Víctor José Asencio-Cuello Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sun, 17 Jan 2021 21:04:27 +0000 Potentialities of oligogalacturonides and chitosaccharides on plant rooting <p>Oligogalacturonides and chitosaccharides are members of a new class of bioactive substances with plant activity known as oligosaccharins. The&nbsp;application of these substances has direct and indirect benef icial effects on plant rooting processes, which are discussed in this work. These substances have been considered second messengers of some classic plant hormones, such as auxins, cytokines and gibberellins, resulting in their much more specif ic activity in the different organs of plants. Their physicochemical and structural characteristics also have a signif icant influence on their biological activity and especially on rooting processes, both in vitro and in vivo. In our study, we discussed positive effects caused by the application of oligogalacturonides and chitosaccharides in the process of rooting, as well as indirect effects related with the&nbsp;increased interaction with symbiotic soil microorganisms such as rhizobacteria and arbuscular mycorrhizal fungi that improve root growth and function in plants.</p> Juan José Reyes-Pérez, Rommel Arturo Ramos-Remache, Luis Tarquino Llerena-Ramos, Miguel Ángel Ramírez-Arrebato, Alejandro Bernardo Falcón-Rodríguez Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sat, 13 Feb 2021 00:44:52 +0000 Analysis of anthocyanins in the purple corn (Zea mays L.) from Peru and its antioxidant properties <p>The purple corn (Zea mays L.), is an important cereal in Peru, which contains polyphenols, among which include flavonoids, being anthocyanins the most important one. The ear (cob and grain) is made up of 85% grain and 15% cob. Its high content of anthocyanin, mainly as cyanidine-3-glucoside (C3G), makes it act as a powerful natural antioxidant, anti-carcinogenic, and anti-inflammatory, it also helps lower blood pressure and high cholesterol, improves blood circulation and promotes tissue regeneration. Because of these important benefits, it arises the need to understand the mechanism of action of anthocyanins in human health. Therefore, the objective of the present review paper is to describe the chemical structure of anthocyanins, what types and factors affect not only its color but also its stability. In the second part, it was detailed the different races and varieties improved of purple corn in Peru, and the amount of anthocyanins found with the different chemical techniques used. Finally, the different biological activities of anthocyanins are described with emphasis in the most important one as a powerful antioxidant. Finding that the optimal extraction conditions of anthocyanins are with 1 g of sample and 15 mL of water with in agitation constant for 15 min at 90 ºC, highlighting the high antioxidant power in both systems in-vitro and ex-vivo.</p> Melissa Rabanal-Atalaya, Alicia Medina-Hoyos Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sun, 17 Jan 2021 21:14:42 +0000 The h index: overvaluation of its use in the assessment of the impact of scientific work in Mexico <p>To judge the impact and relevance of the results of the scientif ic work, the researchers are subjected to evaluation processes that involve records of publications and the corresponding citations. For this purpose, some index has been developed. Among them, the index proposed by Hirsch are considered in most evaluation processes. The analysis developed here concludes that the h-index does not measure the relative contribution of a researcher in publications, especially in those that are generated by groups of between 80 and 700 authors. Likewise, the aforementioned index does not consider book publications, nor the contribution of a researcher in the formation of human resources, nor the formation of scientif ic groups or societies. Nor does the h index value contributions in technological innovation, in the dissemination of scientif ic knowledge. In a relevant way, it must be emphasized that the h index does not take into account the contribution of a specif ic researcher to the establishment of public policies generated through scientif ic research, which can be strategic and of local, regional and even national relevance. Assessing the work of a researcher based primarily on its h-index is not only limited and unfair, but it is severely distorting the priorities of the new generations of scientists in Mexico. Scientists must not forget that we are subsidized with public resources, which leads to not only being widely cited at the international level, but also to contribute to the formation of human resources, to the resolution of local and national problems, to influence the generation of Public Policies and in the social appropriation of knowledge. Therefore, the need to manage a system that considers these aspects is essential in order to evaluate the possible impact of the work of each researcher.</p> Alfredo Ortega-Rubio, Bernardo Murillo-Amador, Enrique Troyo-Diéguez, Ricardo David Valdez-Cepeda Copyright (c) 2021 REVISTA TERRA LATINOAMERICANA Sun, 17 Jan 2021 21:15:29 +0000