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Mulch application as the overarching factor explaining increase in soil organic carbon stocks under conservation agriculture in two 8-year-old experiments in Zimbabwe

Regis Chikowo Christian Thierfelder Marc Corbeels (2024, [Artículo])

Conservation agriculture (CA), combining reduced or no tillage, permanent soil cover, and improved rotations, is often promoted as a climate-smart practice. However, our understanding of the impact of CA and its respective three principles on top- and subsoil organic carbon stocks in the low-input cropping systems of sub-Saharan Africa is rather limited. This study was conducted at two long-term experimental sites established in Zimbabwe in 2013. The soil types were abruptic Lixisols at Domboshava Training Centre (DTC) and xanthic Ferralsol at the University of Zimbabwe farm (UZF). The following six treatments, which were replicated four times, were investigated: conventional tillage (CT), conventional tillage with rotation (CTR), no tillage (NT), no tillage with mulch (NTM), no tillage with rotation (NTR), and no tillage with mulch and rotation (NTMR). Maize (Zea mays L.) was the main crop, and treatments with rotation included cowpea (Vigna unguiculata L. Walp.). The soil organic carbon (SOC) concentration and soil bulk density were determined for samples taken from depths of 0–5, 5–10, 10–15, 15–20, 20–30, 30–40, 40–50, 50–75 and 75–100 cm. Cumulative organic inputs to the soil were also estimated for all treatments. SOC stocks at equivalent soil mass were significantly (p<0.05) higher in the NTM, NTR and NTMR treatments compared with the NT and CT treatments in the top 5 cm and top 10 cm layers at UZF, while SOC stocks were only significantly higher in the NTM and NTMR treatments compared with the NT and CT treatments in the top 5 cm at DTC. NT alone had a slightly negative impact on the top SOC stocks. Cumulative SOC stocks were not significantly different between treatments when considering the whole 100 cm soil profile. Our results show the overarching role of crop residue mulching in CA cropping systems with respect to enhancing SOC stocks but also that this effect is limited to the topsoil. The highest cumulative organic carbon inputs to the soil were observed in NTM treatments at the two sites, and this could probably explain the positive effect on SOC stocks. Moreover, our results show that the combination of at least two CA principles including mulch is required to increase SOC stocks in these low-nitrogen-input cropping systems.

CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA SOIL ORGANIC CARBON CONSERVATION AGRICULTURE EXPERIMENTATION CROP MANAGEMENT

Socio-spatial segregation of socio-environmental assets of public green spaces in the city of Durango, Mexico

Carlos Alejandro Custodio González Tania Ortiz Patricia Catalina Medina Pérez (2024, [Artículo, Artículo])

The current development model's accumulation logic has resulted in the emergence and consolidation of social processes like segregation, leading to differentiated access and availability of urban goods and services among social groups based on socioeconomic, ethnic, or societal standing. The current development model's accumulation logic has resulted in the emergence and consolidation of social processes like segregation, leading to differentiated access and availability of urban goods and services among social groups based on socioeconomic, ethnic, or societal standing. This disparity impacts employment levels, educational performance, urban decay, and environmental degradation. In this context, the article aims to examine the socio-spatial segregation in the access to socio-environmental amenities provided by public green spaces (EVP) in a medium-sized city, specifically Durango, Mexico. The analysis utilizes spatial analysis and statistical methods that involve five variables associated with EVPs: surface area, percentage, number, density, and the socioeconomic level of the population. A spatial pattern of segregation was identified through these variables, resulting in four clusters that impact how the city of Durango is inhabited, produced, reproduced, lived, and constructed.

sociospatial exclusion public space spatial autocorrelation spatial patterns spatial justice exclusión socioespacial espacio público autocorrelación espacial patrones espaciales justicia espacial CIENCIAS SOCIALES CIENCIAS SOCIALES

Conflictos hídricos: lecciones para el presente

ADRIAN PEDROZO ACUÑA (2021, [Artículo])

doi.org/10.24850/b-imta-perspectivas-2021-02

La magnitud y el número de conflictos hídricos que se están registrando en todo el mundo señalan la necesidad de utilizar el conocimiento de punta y la capacidad tecnológica y social de las instituciones de investigación para asistir a todas las personas atrapadas en conflictos hídricos. En México, tan solo el año pasado, fuimos testigos de conflictos hídricos en la cuenca del río Bravo por los volúmenes de agua compartidos en una cuenca por diversos usuarios. Estas son tan solo unas facetas de la realidad de los conflictos hídricos que se están presentando en el mundo y, sin duda, constituyen un indicador de la necesidad de nuevos paradigmas para la gestión del agua, ya que es imposible continuar aceptando el gran impacto que estas tensiones generan sobre las vidas de millones de personas y ecosistemas que dependen de los flujos de agua. Estos conflictos tienen su origen en la desecación de ríos, la sobreexplotación de acuíferos y, desde luego, la falta de atención a dimensiones sociales, como la equidad y la justicia.

Conflictos por agua Gestión del agua Explotación de recursos naturales INGENIERÍA Y TECNOLOGÍA

Las cáscaras de naranja: ¿Desechos de la agricultura o riqueza farmacéutica?

ROLFFY RUBEN ORTIZ ANDRADE JESUS ALFREDO ARAUJO LEON Gregoreo Centeno Hoil MICHELLE SANSORES CHUC (2023, [Artículo])

México se encuentra entre los diez primeros países con la mayor producción de cítricos, siendo Yucatán uno de los principales estados productores, en particular, de naranjas. Actualmente, la producción de cítricos se utiliza para la extracción de jugo para alimentos y bebidas. Sin embargo, las cáscaras de naranjas son desechadas o subutilizadas. En este ensayo abordamos una perspectiva del potencial médico y económico que existe en las cáscaras de naranja y que podrían ser una riqueza farmacéutica por su alto contenido de flavonoides, moléculas que han sido objeto de estudio para la prevénción de la diabetes, hipertensión y la obesidad.

CITRUS SINENSIS DIABETES HESPERIDINA HIPERTENSION NARINGENINA OBESIDAD BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) EXPLOTACIÓN DE LOS CULTIVOS EXPLOTACIÓN DE LOS CULTIVOS

The water crisis in the south-central region of the Chihuahua State and the 1997 UN Convention

Jorge Arturo Salas Plata Mendoza Thelma J. Garcia (2022, [Artículo, Artículo])

The present writing focuses on the water crisis in the south-central part of Chihuahua State in the year 2020. Recent literature points to the drought, excess demand for the vital liquid and overpopulation of this region, among other issues, as the causes of the emergency. This paper argues that the reasons mentioned above are not causes, but effects of an economic policy of capital valorization and accumulation, which go far beyond the carrying capacity of the ecosystems and their capacity to regulate the polluting processes. The obsolescence of the water treaties between Mexico and the US make it necessary to consider other alternatives such as the 1997 UN Convention on water.

Chihuahua water crisis hydro-agricultural crisis carrying capacity expansive growth 1997 UN Convention Ecological Economics crisis del agua crisis hidroagrícola capacidad de carga crecimiento expansivo Convención de la ONU de 1997 Economía Ecológica CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA

On-farm assessment of yield and quality traits in durum wheat

Facundo Tabbita Iván Ortíz-Monasterios Francisco Javier Pinera-Chavez Maria Itria Ibba Carlos Guzman (2023, [Artículo])

BACKGROUND: Durum wheat is key source of calories and nutrients for many regions of the world. Demand for it is predicted to increase. Further efforts are therefore needed to develop new cultivars adapted to different future scenarios. Developing a novel cultivar takes, on average, 10 years and advanced lines are tested during the process, in general, under standardized conditions. Although evaluating candidate genotypes for commercial release under different on-farm conditions is a strategy that is strongly recommended, its application for durum wheat and particularly for quality traits has been limited. This study evaluated the grain yield and quality performance of eight different genotypes across five contrasting farmers’ fields over two seasons. Combining different analysis strategies, the most outstanding and stable genotypes were identified. RESULTS: The analyses revealed that some traits were mainly explained by the genotype effect (thousand kernel weight, flour sodium dodecyl sulfate sedimentation volume, and flour yellowness), others by the management practices (yield and grain protein content), and others (test weight) by the year effect. In general, yield showed the highest range of variation across genotypes, management practices, and years and test weight the narrowest range. Flour yellowness was the most stable trait across management conditions, while yield-related traits were the most unstable. We also determined the most representative and discriminative field conditions, which is a beneficial strategy when breeders are constrained in their ability to develop multi-environment experiments. CONCLUSIONS: We concluded that assessing genotypes in different farming systems is a valid and complementary strategy for on-station trials for determining the performance of future commercial cultivars in heterogeneous environments to improve the breeding process and resources.

Wheat Quality GGE Analysis Flour Yellowness CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA FLOURS WHEAT QUALITY YIELDS FIELD EXPERIMENTATION

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