Closing the yield gap of soybean (Glycine max (L.) Merril) in Southern Africa: a case of Malawi, Zambia, and Mozambique

Siyabusa Mkuhlani Isaiah Nyagumbo (2023, [Artículo])

Introduction: Smallholder farmers in Sub-Saharan Africa (SSA) are increasingly producing soybean for food, feed, cash, and soil fertility improvement. Yet, the difference between the smallholder farmers’ yield and either the attainable in research fields or the potential from crop models is wide. Reasons for the yield gap include low to nonapplication of appropriate fertilizers and inoculants, late planting, low plant populations, recycling seeds, etc. Methods: Here, we reviewed the literature on the yield gap and the technologies for narrowing it and modelled yields through the right sowing dates and suitable high-yielding varieties in APSIM. Results and Discussion: Results highlighted that between 2010 and 2020 in SSA, soybean production increased; however, it was through an expansion in the cropped area rather than a yield increase per hectare. Also, the actual smallholder farmers’ yield was 3.8, 2.2, and 2.3 times lower than the attainable yield in Malawi, Zambia, and Mozambique, respectively. Through inoculants, soybean yield increased by 23.8%. Coupling this with either 40 kg ha−1 of P or 60 kg ha−1 of K boosted the yields by 89.1% and 26.0%, respectively. Overall, application of 21–30 kg ha-1 of P to soybean in SSA could increase yields by about 48.2%. Furthermore, sowing at the right time increased soybean yield by 300%. Although these technologies enhance soybean yields, they are not fully embraced by smallholder farmers. Hence, refining and bundling them in a digital advisory tool will enhance the availability of the correct information to smallholder farmers at the right time and improve soybean yields per unit area.

Decision Support Tools Digital Tools Site-Specific Recommendations CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA DECISION SUPPORT SYSTEMS LEGUMES YIELDS SOYBEANS

Metals pollution in El Limón lagoon, Chiapas, Mexico

MARIA TERESA LEAL ASCENCIO SAUL MIRANDA ALONSO Elena María Otazo Sanchez Francisco Prieto García (2009, [Artículo])

La laguna El Limón, en el municipio de Reforma, Chiapas, México, ha presentado mortandad masiva de peces, lo que llevó a realizar un estudio más profundo que determinara el grado de contaminación de la laguna, así como las causas posibles de los eventos. Los resultados muestran que en los sedimentos de la laguna las concentraciones promedio de Zn, Ni, Cr, Cd y Cu rebasan los límites recomendados en Canadá y Estados Unidos para evitar la aparición de efectos biológicos nocivos en especies acuáticas. Es de especial mención la acumulación de Zn, que presenta una concentración máxima de 1360 mg/kg, presumiblemente asociada al uso de este metal como catalizador en una planta procesadora de gas. Si bien las descargas industriales que vierten a la laguna cumplen con los estándares establecidos en México para metales, esto no ha sido suficiente para evitar su acumulación en los sedimentos, lo cual demuestra que las normas existentes para las descargas de aguas residual industrial deben aumentar sus restricciones y tomar en cuenta el tipo de cuerpo receptor al que vierten. En el caso del uso de agua residual o contaminada para riego, la acumulación puede darse en los suelos agrícolas, pasando eventualmente a los cultivos, lo que tampoco es deseable.

Lagunas Contaminación del agua Metales Zinc INGENIERÍA Y TECNOLOGÍA

La construcción del sujeto leproso

Yaminel Bernal Astorga (2008, [Tesis de doctorado])

La lepra es una enfermedad que hasta el día de hoy continúa entre nosotros, irrumpe en la vida de las personas transformando su existencia de manera significativa, pues en cada una ellas delinean marcas que trascienden en el cuerpo, en las relaciones, en lo que hacen y en lo que piensan. Pero, sobre todo, cuando los individuos son identificados como “enfermos de lepra”, de entrada, quedan sujetos a los significados que anteceden a este padecimiento y que, generalmente, están vinculados con las expresiones de horror y miedo debido a la deformidad, la putrefacción, la discapacidad y el contagio que puede causar. De este modo, formular que el “enfermo de lepra” es objeto del dolor, las transformaciones en el cuerpo, los señalamientos, las exclusiones… son percepciones que, prácticamente, pueden vislumbrarse de antemano. Sin embargo, me interesa ir más allá de lo que hasta ahora se tiene por sentado en relación con el “enfermo de lepra”, e incluso la forma en la que puede ser problematizado.

Lepra Piel -- Enfermedades CIENCIAS SOCIALES SOCIOLOGÍA PROBLEMAS SOCIALES ENFERMEDAD ENFERMEDAD

Hacia Sistemas Sustentables Agrícola Ganaderos en el Altiplano Sur de Bolivia 2022

Santiago Lopez-Ridaura Ravi Gopal Singh (2022, [Libro])

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA GANADERÍA AGRICULTURA DE CONSERVACIÓN CAMBIO CLIMÁTICO LLUVIA SUELO FERTILIDAD DEL SUELO SEQUÍA

Estimating lime requirements for tropical soils: Model comparison and development

Fernando Aramburu Merlos João Vasco Silva Frédéric Baudron Robert Hijmans (2023, [Artículo])

Acid tropical soils may become more productive when treated with agricultural lime, but optimal lime rates have yet to be determined in many tropical regions. In these regions, lime rates can be estimated with lime requirement models based on widely available soil data. We reviewed seven of these models and introduced a new model (LiTAS). We evaluated the models’ ability to predict the amount of lime needed to reach a target change in soil chemical properties with data from four soil incubation studies covering 31 soil types. Two foundational models, one targeting acidity saturation and the other targeting base saturation, were more accurate than the five models that were derived from them, while the LiTAS model was the most accurate. The models were used to estimate lime requirements for 303 African soil samples. We found large differences in the estimated lime rates depending on the target soil chemical property of the model. Therefore, an important first step in formulating liming recommendations is to clearly identify the soil property of interest and the target value that needs to be reached. While the LiTAS model can be useful for strategic research, more information on acidity-related problems other than aluminum toxicity is needed to comprehensively assess the benefits of liming.

Exchangeable Acidity Aluminum Saturation Calcium Carbonate Equivalent CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CHEMICOPHYSICAL PROPERTIES LIMES TROPICAL ZONES ACID SOILS ALUMINIUM BASE SATURATION CALCIUM CARBONATE

Diversifying with grain legumes amplifies carbon in management-sensitive soil organic carbon pools on smallholder farms

Regis Chikowo Sieglinde Snapp (2023, [Artículo])

Crop diversification with grain legumes has been advocated as a means to increase agroecological resilience, diversify livelihoods, boost household nutrition, and enhance soil health and fertility in cereal-based cropping systems in sub-Saharan Africa and around the world. Soil organic carbon (SOC) is a primary indicator of soil health and there is limited data regarding SOC pools and grain legume diversification on smallholder farms where soils are often marginal. In Malawi, a range of legume diversification options are under investigation, including rotations and a doubled-up legume rotation (DLR) system in which two compatible legumes are intercropped and then rotated with a cereal. The impact of the DLR system on SOC has not yet been determined, and there is a lack of evidence regarding SOC status over a gradient of simple to complex grain legume diversified systems. We address this knowledge gap by evaluating these systems in comparison to continuous sole maize (Zea mays L.) at three on-farm trial sites in central Malawi. After six years of trial establishment, we measured SOC in bulk soils and aggregate fractions and in faster cycling SOC pools that respond more rapidly to management practices, including water extractable organic carbon (WEOC), particulate organic matter carbon (POM-C), potentially mineralizable carbon (C), and macroaggregate C. Cropping treatment differences were not seen in bulk SOC or total N, but they were apparent in SOC pools with a shorter turnover time. The DLR system of intercropped pigeonpea (Cajanus cajan (L.) Millsp.) and groundnut (Arachis hypogaea L.) rotated with maize had higher WEOC, POM-C, potentially mineralizable C, macroaggregate and microaggregate C values than continuous maize. Of the single legume rotations, the pigeonpea-maize rotation had more mineralizable C and microaggregate C compared to continuous maize, while the groundnut-maize rotation had similar C values to the maize system. Overall, this study shows the potential for crop rotations diversified with grain legumes to enhance C in management sensitive SOC pools, and it is one of the first reports to show this effect on smallholder farm sites.

Crop Diversification Water Extractable Organic Carbon CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA DIVERSIFICATION LEGUMES PARTICULATE ORGANIC MATTER SOIL ORGANIC CARBON

Institutionalization of leftist utopias in Latin America: a case study

Guillem Compte Nunes (2023, [Artículo, Artículo])

Faced with popular dissatisfaction with liberal-capitalist democracy, at the beginning of the 21st century there is a governmental shift to the left in Latin America, in which Mexico is recently participating, with the arrival of the Morena party to power. The social movements that promote these political projects convey leftist utopias that seek to institutionalize themselves in political systems and public policies. However, this process of utopian institutionalization presents tensions and contradictions within the so-called party-movements. In this paper I present a methodological proposal for utopian analysis, which I apply to the “Colectivo La Calle”, a group that is part of the lopezobradorista movement in Mexico. I analyze three utopias mediated by this group and find that indeed the Colectivo is mobilizing against Morena’s pragmatism. This result adds to previous literature, which, given contemporary governmental experiences, questions the ability of the Latin American institutional left to overcome conservative hegemony.

utopía lopezobradorismo México acción colectiva Morena CIENCIAS SOCIALES CIENCIAS SOCIALES Utopia Mexico collective action

El proceso lluvia-escurrimiento-erosión en laderas y microcuencas instrumentadas

PEDRO RIVERA RUIZ JOSE LUIS OROPEZA MOTA ENRIQUE MEJIA SAENZ LUIS MARIO TAPIA VARGAS EUSEBIO JR. VENTURA RAMOS (2012, [Artículo])

Se evaluó el proceso lluvia-escurrimiento-erosión en diferentes prácticas de manejo con cultivos de escarda y de cobertera en lotes de escurrimiento, así como también en una parcela con cultivo de maíz, establecidos en laderas de suelos andosoles de la cuenca Villa Victoria del Sistema Cutzamala durante 2007. Se presentaron 168 eventos de lluvia de los cuales sólo 14 generaron escurrimiento superficial y erosión del suelo. Los resultados mostraron que en pendientes de 30%, los cultivos de escarda en surcos al contorno tuvieron una eficiencia promedio del 40% para el control de los escurrimientos y la erosión del suelo; por otro lado, en los cultivos de cobertera, su eficiencia fue del 62%.

Lluvias Erosión del suelo Agricultura Escurrimiento natural INGENIERÍA Y TECNOLOGÍA

Análisis de cuatro variables del período de lluvias asociadas al cultivo de maíz temporal

Analysis of four variables associated with rainy seasonal in maize cultivation

MAURO IÑIGUEZ COVARRUBIAS WALDO OJEDA BUSTAMANTE CARLOS DIAZ DELGADO (2013, [Artículo])

Caracterizar y conocer las variables: inicio, duración, terminación de la estación lluviosa y la cantidad de precipitación con fines de precisar su magnitud y relacionarlas con la agricultura bajo condiciones de temporal, es y ha sido una preocupación importante para los agricultores y estudiosos de las ciencias agrícolas. En la región centro norte de México este problema se acentúa por la alta variabilidad de la estación lluviosa y la gran dependencia climática de la agricultura de temporal. La metodología indicada recrea cuatro variables climáticas de la estación lluviosa, analizadas por métodos reconocidos, y con base en un análisis probabilístico se asocian a la agricultura del cultivo del maíz de temporal. El estudio fue realizado para la región ubicada en el sur del estado de Zacatecas, México, sobre la estación climatológica Tlaltenango.

Agricultura de temporal Lluvias Cultivos alimenticios INGENIERÍA Y TECNOLOGÍA

Influence of novel coconut oil and beeswax edible coating and MAP on postharvest shelf life and quality attributes of lemon at low temperature

Mohammad Mainuddin Molla Ashfak Ahmed Sabuz Md Abdul Matin (2023, [Artículo])

Weight loss, turning of peel colour from green to yellow and microbial infections are the major postharvest problems of lemon. Lipid-based edible coatings and modified atmospheric packaging (MAP) are effective techniques in maintaining postharvest quality of fruits for long-term storage. With this view, an investigation was conducted for the preservation of green lemon using coconut oil and beeswax edible coating and MAP during storage at low temperature. Physiologically matured lemons were collected and washed with potable water; fruit surface water was removed and then coated with coconut oil-beeswax (90:10) or only coconut oil. After coating, lemons were packaged in MAP or kept in open crates and stored at 12±1 °C and 85±5% relative humidity (RH) for 8 weeks and a week interval, the sampling was conducted. The results revealed that coconut oil-beeswax coating had immense effect on retaining shiny green colour, reducing respiration, weight loss, shrivelling and preserving firmness and ascorbic acid of lemon throughout the storage. On the other hand, MAP mainly helped to retain moisture & firmness and reduce shrivelling. Uncoated lemons kept open lost the highest amount of ascorbic acid and retained only 13.7 mg/100 g that is significantly (p < 0.05) less than the lemons of all other treatments at 8th week of storage period. While lemons coated with coconut oil-beeswax and packaged in MAP was preserved the highest amount (24.2 mg/100 g) of ascorbic acid and there was no significant difference (p < 0.05) with the amount of ascorbic acid content of lemons coated with only coconut oil and packaged in MAP at the last week (8th week) of storage. Hue angle value was 93.4 in uncoated lemons packaged in MAP while it was 113.67 in coconut oil-beeswax coated lemon kept open and 112.64 in lemon coated with coconut oil-beeswax and packaged in MAP at 8th week of storage. Based on all sensory, physical and chemical parameters uncoated lemons kept open was acceptable up to 1 week, coconut oil-beeswax coated lemon kept open was 6 weeks and coconut oil-beeswax coated lemon packaged in MAP was 8 weeks with good quality and shiny green colour.

Edible Coating Sensory Quality Hue Angle Yellowing CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA EDIBLE FILMS RESPIRATION RATE LEMONS MODIFIED ATMOSPHERE PACKAGING COLD