Búsqueda avanzada


Área de conocimiento




90 resultados, página 3 de 9

Appraisal of complementarity of subsurface drip fertigation and conservation agriculture for physiological performance and water economy of maize

C.M. Parihar Hari Sankar Nayak Dipaka Ranjan Sena Renu Pandey Mahesh Gathala ML JAT (2023, [Artículo])

The Indo-Gangetic Plains (IGP) in north-west (NW) India are facing a severe decline in ground water due to prevalent rice-based cropping systems. To combat this issue, conservation agriculture (CA) with an alternative crop/s, such as maize, is being promoted. Recently, surface drip fertigation has also been evaluated as a viable option to address low-nutrient use efficiency and water scarcity problems for cereals. While the individual benefits of CA and sub-surface drip (SSD) irrigation on water economy are well-established, information regarding their combined effect in cereal-based systems is lacking. Therefore, we conducted a two-year field experiment in maize, under an ongoing CA-based maize-wheat system, to evaluate the complementarity of CA with SSD irrigation through two technological interventions–– CA+ (residue retained CA + SSD), PCA+ (partial CA without residue + SSD) – at different N rates (0, 120 and 150 kg N ha-1) in comparison to traditional furrow irrigated (FI) CA and conventional tillage (CT) at 120 kg N ha-1. Our results showed that CA+ had the highest grain yield (8.2 t ha-1), followed by PCA+ (8.1 t ha-1). The grain yield under CA+ at 150 kg N ha-1 was 27% and 30% higher than CA and CT, respectively. Even at the same N level (120 kg N ha-1), CA+ outperformed CA and CT by 16% and 18%, respectively. The physiological performance of maize also revealed that CA+ based plots with 120 kg N ha-1 had 12% and 3% higher photosynthesis rate at knee-high and silking, respectively compared to FI-CA and CT. Overall, compared to the FI-CA and CT, SSD-based CA+ and PCA+ saved 54% irrigation water and increased water productivity (WP) by more than twice. Similarly, a greater number of split N application through fertigation in PCA+ and CA+ increased agronomic nitrogen use efficiency (NUE) and recover efficiency by 8–19% and 14–25%, respectively. Net returns from PCA+ and CA+ at 150 kg N ha-1 were significantly higher by US$ 491 and 456, respectively than the FI-CA and CT treatments. Therefore, CA coupled with SSD provided tangible benefits in terms of yield, irrigation water saving, WP, NUE and profitability. Efforts should be directed towards increasing farmers’ awareness of the benefits of such promising technology for the cultivating food grains and commercial crops such as maize. Concurrently, government support and strict policies are required to enhance the system adaptability.

Net Returns Subsurface Drip Irrigation Subsurface Drip Fertigation CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA EFFICIENCY GRAIN NITROGEN PHOTOSYNTHESIS PHYSIOLOGY WATER SUPPLY CONSERVATION AGRICULTURE CONVENTIONAL TILLAGE FERTIGATION GROUNDWATER NITROGEN-USE EFFICIENCY WATER PRODUCTIVITY

The social responsibility of tobacco production in Nayarit. Who pays the price?

Dagoberto De Dios Hernández Jesús Antonio Madera Pacheco (2023, [Artículo, Artículo])

In Nayarit, Mexico, there is an Integrated System of Tobacco Production (SIPT) which operates mainly with the participation of campesino families. However, for some preparatory work and to guarantee the harvest, local jornaleros and indigenous migrant families from the mountainous regions of Nayarit, Jalisco, Durango, and Zacatecas are hired, manly on a temporarily basis. They live for several months in precarious conditions in the houses and yards of the growers and on the agricultural plots. Since the Marco’s Convention and the General Law on Tobacco Control, the companies that control the SIPT have adopted new narratives and strategies for managing and sustaining their businesses, mainly emphasizing the so-called Corporate Social Responsibility (CSR). The objective of this article is to analyze the CSR actions of the tobacco companies from an approach of accumulation by dispossession, understanding CSR as a capitalist tool for the extraction of surplus value. With the support of a qualitative methodology, based on bibliographic and hemerographic review, direct observation, field diaries and interviews, also corporate actions comprised between 2018 and 2023 have also been documented. British American Tobacco and Tabacos del Pacífico Norte have "sponsored" the operation of the Florece centers and the Sustenta program in the tobacco fields of Nayarit, even though, in the tobacco reality of the tobacco industry the operation of such programs and their costs are assumed and absorbed by the growers, while the companies disseminate an image of sustainable business management.

Tobacco Social Responsibility Tobacco companies Indigenous families CMCT Tabaco Responsabilidad social Empresas tabacaleras Familias indígenas CIENCIAS SOCIALESCIENCIAS SOCIALES CIENCIAS SOCIALES

The social responsibility of tobacco production in Nayarit. Who pays the price?

Dagoberto De Dios Hernández Jesús Antonio Madera Pacheco (2023, [Artículo, Artículo])

In Nayarit, Mexico, there is an Integrated System of Tobacco Production (SIPT) which operates mainly with the participation of campesino families. However, for some preparatory work and to guarantee the harvest, local jornaleros and indigenous migrant families from the mountainous regions of Nayarit, Jalisco, Durango, and Zacatecas are hired, manly on a temporarily basis. They live for several months in precarious conditions in the houses and yards of the growers and on the agricultural plots. Since the Marco’s Convention and the General Law on Tobacco Control, the companies that control the SIPT have adopted new narratives and strategies for managing and sustaining their businesses, mainly emphasizing the so-called Corporate Social Responsibility (CSR). The objective of this article is to analyze the CSR actions of the tobacco companies from an approach of accumulation by dispossession, understanding CSR as a capitalist tool for the extraction of surplus value. With the support of a qualitative methodology, based on bibliographic and hemerographic review, direct observation, field diaries and interviews, also corporate actions comprised between 2018 and 2023 have also been documented. British American Tobacco and Tabacos del Pacífico Norte have "sponsored" the operation of the Florece centers and the Sustenta program in the tobacco fields of Nayarit, even though, in the tobacco reality of the tobacco industry the operation of such programs and their costs are assumed and absorbed by the growers, while the companies disseminate an image of sustainable business management.

Tobacco Social Responsibility Tobacco companies Indigenous families CMCT Tabaco Responsabilidad social Empresas tabacaleras Familias indígenas CIENCIAS SOCIALESCIENCIAS SOCIALES CIENCIAS SOCIALES

Bundling subsurface drip irrigation with no-till provides a window to integrate mung bean with intensive cereal systems for improving resource use efficiency

Manish Kakraliya madhu choudhary Mahesh Gathala Parbodh Chander Sharma ML JAT (2024, [Artículo])

The future of South Asia’s major production system (rice–wheat rotation) is at stake due to continuously aggravating pressure on groundwater aquifers and other natural resources which will further intensify with climate change. Traditional practices, conventional tillage (CT) residue burning, and indiscriminate use of groundwater with flood irrigation are the major drivers of the non-sustainability of rice–wheat (RW) system in northwest (NW) India. For designing sustainable practices in intensive cereal systems, we conducted a study on bundled practices (zero tillage, residue mulch, precise irrigation, and mung bean integration) based on multi-indicator (system productivity, profitability, and efficiency of water, nitrogen, and energy) analysis in RW system. The study showed that bundling conservation agriculture (CA) practices with subsurface drip irrigation (SDI) saved ~70 and 45% (3-year mean) of irrigation water in rice and wheat, respectively, compared to farmers’ practice/CT practice (pooled data of Sc1 and Sc2; 1,035 and 318 mm ha−1). On a 3-year system basis, CA with SDI scenarios (mean of Sc5–Sc8) saved 35.4% irrigation water under RW systems compared to their respective CA with flood irrigation (FI) scenarios (mean of Sc3 and Sc4) during the investigation irrespective of residue management. CA with FI system increased the water productivity (WPi) and its use efficiency (WUE) by ~52 and 12.3% (3-year mean), whereas SDI improved by 221.2 and 39.2% compared to farmers practice (Sc1; 0.69 kg grain m−3 and 21.39 kg grain ha−1 cm−1), respectively. Based on the 3-year mean, CA with SDI (mean of Sc5–Sc8) recorded −2.5% rice yield, whereas wheat yield was +25% compared to farmers practice (Sc1; 5.44 and 3.79 Mg ha−1) and rice and wheat yield under CA with flood irrigation were increased by +7 and + 11%, compared to their respective CT practices. Mung bean integration in Sc7 and Sc8 contributed to ~26% in crop productivity and profitability compared to farmers’ practice (Sc1) as SDI facilitated advancing the sowing time by 1 week. On a system basis, CA with SDI improved energy use efficiency (EUE) by ~70% and partial factor productivity of N by 18.4% compared to CT practices. In the RW system of NW India, CA with SDI for precise water and N management proved to be a profitable solution to address the problems of groundwater, residue burning, sustainable intensification, and input (water and energy) use with the potential for replication in large areas in NW India.

Direct Seeded Rice Subsurface Drip Irrigation Economic Profitability Energy and Nitrogen Efficiency CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CONSERVATION AGRICULTURE RICE SUBSURFACE IRRIGATION IRRIGATION SYSTEMS WATER PRODUCTIVITY ECONOMIC VIABILITY ENERGY EFFICIENCY NITROGEN-USE EFFICIENCY

Expanding the WOFOST crop model to explore options for sustainable nitrogen management: A study for winter wheat in the Netherlands

João Vasco Silva Pytrik Reidsma (2024, [Artículo])

Nitrogen (N) management is essential to ensure crop growth and to balance production, economic, and environmental objectives from farm to regional levels. This study aimed to extend the WOFOST crop model with N limited production and use the model to explore options for sustainable N management for winter wheat in the Netherlands. The extensions consisted of the simulation of crop and soil N processes, stress responses to N deficiencies, and the maximum gross CO2 assimilation rate being computed from the leaf N concentration. A new soil N module, abbreviated as SNOMIN (Soil Nitrogen for Organic and Mineral Nitrogen module) was developed. The model was calibrated and evaluated against field data. The model reproduced the measured grain dry matter in all treatments in both the calibration and evaluation data sets with a RMSE of 1.2 Mg ha−1 and the measured aboveground N uptake with a RMSE of 39 kg N ha−1. Subsequently, the model was applied in a scenario analysis exploring different pathways for sustainable N use on farmers' wheat fields in the Netherlands. Farmers' reported yield and N fertilization management practices were obtained for 141 fields in Flevoland between 2015 and 2017, representing the baseline. Actual N input and N output (amount of N in grains at harvest) were estimated for each field from these data. Water and N-limited yields and N outputs were simulated for these fields to estimate the maximum attainable yield and N output under the reported N management. The investigated scenarios included (1) closing efficiency yield gaps, (2) adjusting N input to the minimum level possible without incurring yield losses, and (3) achieving 90% of the simulated water-limited yield. Scenarios 2 and 3 were devised to allow for soil N mining (2a and 3a) and to not allow for soil N mining (2b and 3b). The results of the scenario analysis show that the largest N surplus reductions without soil N mining, relative to the baseline, can be obtained in scenario 1, with an average of 75%. Accepting negative N surpluses (while maintaining yield) would allow maximum N input reductions of 84 kg N ha−1 (39%) on average (scenario 2a). However, the adjustment in N input for these pathways, and the resulting N surplus, varied strongly across fields, with some fields requiring greater N input than used by farmers.

Crop Growth Models WOFOST CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CROPS NITROGEN-USE EFFICIENCY WINTER WHEAT SOIL WATER

Gobernanza de múltiple escala para la gestión local del agua de consumo humano en América Latina: estudios de caso en Costa Rica, Honduras y México

Multilevel governance for local management of drinking water in Latin America: case studies from Costa Rica, Honduras and Mexico

FERNANDO GUMETA GOMEZ ELVIRA DURAN MEDINA David Brayden (2017, [Artículo])

El abastecimiento del agua para consumo humano a escala local puede depender de la participación social. Se compararon tres regímenes de gobernanza para gestión del agua basado en acción colectiva y en entidades anidadas: 1) Asociaciones Administradoras de Sistemas de Acueductos y Alcantarillados Sanitario (ASADAS) en Costa Rica, 2) Juntas Ad-ministradoras del Agua (JAA) en Honduras y 3) Comités de Agua (CA) en Oaxaca, México. Se analizaron el marco legal, la estructura y operatividad y la eficiencia en la provisión y conservación de los recursos hídricos mediante revisión documental, observación partici-pativa y entrevistas informales.ASADAS y JAA son reconocidas legalmente, mientras que los CA no tienen soporte en el marco legal mexicano. Los regímenes mostraron estructuras y operatividad análoga, así como tendencias similares hacia eficiencia en la provisión del agua y en asegurar la recarga hídrica, pero capacidades económicas diferentes. Reconocer y empoderar los CA en México podría aumentar y garantizar el abastecimiento de agua a el largo plazo

Adequate supply of drinking water at local level depends, in many cases on community participation. We compare three governance regimes for drinking water management based on multilevel collective action: 1) ASADAS in Costa Rica, 2) Water Boards (JAA, for its acronym in spanish) in Honduras and 3) Water User Committees (CA, for its acronym in spanish) in Mexico. Our data is based on participant observation, and formal and informal interviews. Legal framework, structure and operation, and efficiency for provision and conservation of water resources are analyzed. ASADAS and Water Boards are legal entities with recog-nized community participation and collective action, while Water Committees have no legal support by the Mexican Government. Regimens showed similar structures and operation, but different economic capabilities and efficiencies in the provision of water and in ensur-ing water recharge. Recognition and empowerment of the Water Committees in Mexico could increase and ensure water provision in the long- term

HUMANIDADES Y CIENCIAS DE LA CONDUCTA Abasto de agua Gobernanza local Comités de agua Oaxaca Sustentabilidad de agua Water supply Local governance Water committees Oaxaca Sustainability of water

Physiological ecology of Mexican CAM plants: history, progress, and opportunities

Joel David Flores Rivas Oscar Briones Villareal JOSE LUIS ANDRADE (2022, [Artículo])

"In Mexico, plants with crassulacean acid metabolism (CAM) are part of the Mexican culture, have different uses and are even emblematic. Unfortunately, only a small fraction of the Mexican CAM plants has been studied physiologically. For this review, the following questions were considered: What ecophysiological studies have been conducted with CAM species native to Mexico? What ecophysiological processes in Mexican CAM plants are the most studied? What type of ecophysiological studies with CAM plants are still needed? A database of scientific studies on CAM plant species from Mexico was documented, including field and laboratory works for species widely distributed, and those studies made outside Mexico with Mexican species. Physiological processes were grouped as germination, photosynthesis, and water relations. Most studies were done for CAM species of Cactaceae, Bromeliaceae, Asparagaceae and Orchidaceae, andmost ecophysiological studies have been done on germination of cacti. Field and laboratory studies on photosynthesis and water relations were mostly for terrestrial cacti and epiphytic bromeliads. There were few physiological studies with CAM seedlings in Mexico and few studies using stable isotopes of water and carbon of CAM plants in the field. More field and laboratory studies of physiological responses and plasticity of CAM plants to multiple stress factors are required to model plant responses to global climate change. In general, more physiological studies are essential for all CAM species and for species of the genus Clusia, with C3-CAM and CAM members, which can become ecologically important under some climate change scenarios."

Asparagaceae Bromeliaceae Cactaceae Germination Photosynthesis Water relations Orchidaceae BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) BIOLOGÍA VEGETAL (BOTÁNICA)