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Tropical deltas and coastal zones Полный текст
2010
Chu, Thai Hoanh
This book with 33 chapters divided into five parts is a compendium of selected papers from the conference that can be broadly categorized as land and water management, fisheries and aquaculture and rice-based agriculture systems. Intensification of aquaculture and rice-based agriculture frequently produces negative effects that range from environmental degradation to social conflict; managing these impacts in a sustainable manner is imperative to protect the social and ecological foundations of tropical deltaic systems. New approaches to the intensification and diversification of rice-based production systems are presented in this book, which could impact positively on the livelihoods of millions who inhabit the deltaic areas of South, South East and East Asia if implemented on a large scale. More importantly, these innovations could begin to reverse man's current exploitive behaviour and ensure the preservation of critical ecosystems. A significant section of the compendium is devoted to the intensification of marine shrimp aquaculture production. Negative impacts associated with shrimp production are well recognized, and several innovative approaches to waste management are presented. Further critical questions are raised over the introduction of exotic shrimp species and the long-term impact this could have on native species, which suggests a cautionary approach to future development. A clear consensus emerged from the conference that highlighted the importance of social mobilization and the role of communities in decision making.
Показать больше [+] Меньше [-]Tropical deltas and coastal zones
2010
Chu, Thai Hoanh
Coastal deltas represent one of the most diverse biophysical regions in the tropical developing world. These regions are also home to large human populations and are significant areas of agricultural production and industrialization. Tropical deltas currently face a number of environmental pressures stemming from their intensive use and rapid development, and new threts are emerging as a result of global climate change and expected sea-level rise. | Focusing on the developing countries of Asia, Africa and South America, chapters explore the impact of development strategies and existing land and water management practices on delta environments. New management techniques are also explored, which address conflicts between rice-based agriculture, aquaculture, fisheries, and the emerging threat of climate change. Illustrating the current key management challenges involved in protecting tropical deltaic systems in the face of environmental change, this book will be an essential reference for students, researchers and policy makers in agriculture, environmental science and aquaculture. --Book Jacket.
Показать больше [+] Меньше [-]Towards the More Efficient Use of Water and Nutrients in Food Legume Cropping Полный текст
2014
n. p. saxena | masood ali | r. dahan | j. p. mishra
Nutrient imbalance and soil moisture stress are the major abiotic constraints limiting productivity of cool season food legumes. These constraints are more pronounced in the semi-arid tropics and sub-tropics which are the principal production zones of chickpea, lentil and faba bean. The legumes are generally grown on residual moisture as a mono crop and consequently face drought especially during the reproductive phase. In recent years, chickpea, lentil, peas and faba bean have been grown in some areas with an irrigated/assured water supply under intensive cropping to sustain cereal based systems. An increased water supply favourably influences productivity in dry environments. Faba bean, French beans and peas show a relatively better response to irrigation. The pod initiation stage is considered most critical with respect to moisture stress. Excessive moisture often has a negative effect on podding and seed yield. Eighty to ninety percent of the nitrogen requirements of leguminous crops is met from N2 fixation hence a dose of 15?25 kg N ha-1 has been recommended. However, in new cropping systems like rice-chickpea, higher doses of 30?40 kg N ha-1 are beneficial. Phosphorus deficiency is wide spread and good responses occur to 20 to 80 kg P2O5 ha-1, depending on the nutrient status of soil, cropping systems and moisture availability. Response to potassium application is localized. The use of 20?30 kg S ha-1 and some of the micronutrients such as Zn, B, Mo and Fe have improved productivity. Band placement of phosphatic fertilizers and use of bio-fertilizers has enhanced the efficiency of applied as well as native P. Foliar applications of some micronutrients have been effective in correcting deficiencies. Water use efficiency has been improved with some management practices such as changed sowing time, balanced nutrition, mulching and tillage | Masood Ali, R. Dahan, J. P. Mishra, N. P. Saxena, 'Towards the More Efficient Use of Water and Nutrients in Food Legume Cropping', Linking Research and Marketing Opportunities for Pulses in the 21st Century, vol. 34, pp.355-368, Springer Netherlands, 2014
Показать больше [+] Меньше [-]Analysis of biofuel production in Ecuador from the perspective of the water-food-energy nexus Полный текст
2021
Terneus Páez, Carlos Francisco | Viteri Salazar, Oswaldo
Biofuels in Ecuador were born with the purpose of achieving an effective substitution of imports of petroleum derivatives. The objective of this research is to analyze the impact that biofuel production has on water, food, and energy, and its contribution to reducing the growing dependence on fossil fuels in the transportation sector in Ecuador. The analysis focuses on ethanol produced from sugar cane, which is used to produce Ecopaís gasoline. The methodology is composed of three parts. For the first part, Geographic Information Systems were used; for the second, the FAO Penman-Monteith method; and, finally, in the third, the energy consumption was obtained through secondary information. As a result, taking the year 2019 as a reference, ethanol became the ninth product with the largest amount of land suitable for agriculture, and the seventh with the most irrigated areas in a country that suffers from malnutrition. Countries with a tropical climate and highly dependent on imports of petroleum derivatives are tempted to implement policies to promote biofuels. However, due to the risks that this renewable fuel represents on food security, other options for reducing its energy dependence should be exhausted.
Показать больше [+] Меньше [-]Quantifying and mapping of water-related ecosystem services for enhancing the security of the food-water-energy nexus in tropical data–sparse catchment Полный текст
2019
Sahle, Mesfin | Saito, Osamu | Fürst, Christine | Yeshitela, Kumelachew
The food-water-energy nexus concept helps to produce an integrative solutions to secure the water-related ecosystem services sustainably. This study aims to quantify and map water provisioning and soil erosion regulating services from both demand and supply sides in a spatially explicit manner. It considers the Wabe River catchment of the Omo-Gibe Basin in tropical data-sparse region of East Africa as a case study and uses the Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) annual and seasonal water yield and sediment delivery models. The water demands and biophysical parameters data were collected from primary and secondary sources and prepared according to the requirement of the models. The models output were validated after conducting sensitivity analysis of the input parameters. The result shows that the rainfall amount of the catchment is highly seasonal, which causes the surface water to vary according to the seasons. The high annual precipitation and low actual evapotranspiration of the catchment resulted high annual water yields. However, the people in the catchment did not satisfied their domestic water demand as result of inaccessibility and poor management of the rain water. The high net supply of water, especially in the rainy season, carries detached top soil via heavy rainfall in the upper catchment areas. Even though the existing land cover and management practices contribute to sediment retention, a large amount of sediment is exported to rivers, which jeopardizes the food and energy security. Thus, the management of water is essential for enhancing the security of the food-water-energy nexus in the catchment. The methods applied in this study can increase spatial understanding of the water-related ecosystem services especially in data–sparse catchments of the tropics, and lead to improvement of water management to enhance the security nexus.
Показать больше [+] Меньше [-]Quesungual Slash & Mulch Agroforestry System (QSMAS): Improving crop water productivity food security and resource quality in the sub-humid tropics Полный текст
2012
e. barrios | miguel angel ayarza | b. mendoza | nancy l. johnson | idupulapati m. rao | edgar amézquita collazos | oscar ferreira | j. rubiano | l.a. welchez | maria eugenia baltodano | a. castro | m.a. rondón | simon e. cook | e. garcía | m. rivera | n. pauli | j. pavon
A. Castro et al., 'Quesungual Slash & Mulch Agroforestry System (QSMAS): Improving crop water productivity food security and resource quality in the sub-humid tropics', 2012
Показать больше [+] Меньше [-]Quesungual slash mulch agroforestry systems (QSMAS): improving crop water productivity, food security and resource quality in the sub-humid tropics Полный текст
2015
j pavon | miguel angel ayarza | e. barrios | idupulapati m. rao | edgar amézquita collazos | oscar ferreira | l.a. welchez | a. castro | m.a. rondón | m rivera peña | e. garcía | d valladares
A. Castro et al., 'Quesungual slash mulch agroforestry systems (QSMAS): improving crop water productivity, food security and resource quality in the sub-humid tropics', Centro Internacional de Agricultura Tropical (CIAT), 2015
Показать больше [+] Меньше [-]Quesungual slash and mulch agroforestry system (QSMAS): Improving crop water productivity, food security and resource quality in the sub-humid tropics Полный текст
2011
e. barrios | miguel angel ayarza | b. mendoza | idupulapati m. rao | edgar amézquita collazos | oscar ferreira | l.a. welchez | maria eugenia baltodano | a. castro | m.a. rondón | e. garcia | m. rivera | n. pauli | j. pavon
The knowledge and principles generated by CPWF-PN15 confirm that QSMAS can be a model production system for implementing conservation agriculture to achieve food security and sustainable development in drought-prone areas of hillsides in the sub-humid tropics, while providing ecosystem services in the face of land degradation and climate change. As an adoptable option to replace the slash and burn traditional system, QSMAS can improve smallholder livelihoods through eco-efficient use and conservation of natural resources. Participatory validation activities suggest that the conservation agriculture principles embedded in QSMAS can be readily accepted by resource- poor farmers and local authorities in similar agroecosystems | A. Castro et al., 'Quesungual slash and mulch agroforestry system (QSMAS): Improving crop water productivity, food security and resource quality in the sub-humid tropics', CGIAR Challenge Program on Water and Food, 2011
Показать больше [+] Меньше [-]Quesungual slash and mulch agroforestry system (QSMAS): Improving crop water productivity food security and resource quality in the sub-humid tropics Полный текст
2012
d. valladares | e. barrios | miguel angel ayarza | idupulapati m. rao | edgar amézquita collazos | oscar ferreira | l.a. welchez | a. castro | m.a. rondón | e. garcía | m. rivera | j. pavon
A. Castro et al., 'Quesungual slash and mulch agroforestry system (QSMAS): Improving crop water productivity food security and resource quality in the sub-humid tropics', CIAT, 2012
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