@article {551, title = {Effects of trees on paddy bund on soil fertility and rice growth in Northeast Thailand}, journal = {Agroforestry Systems}, volume = {18}, year = {1992}, month = {June 1992}, pages = {213-223}, abstract = {

A study was conducted in Northeast Thailand on six rice paddy fields on a farm with similar soil (Aquic Quartzipsamments) and with a single tree on the paddy bund. There were 4 tree species: Parinarium anamense, Dipterocarpus obtusifolius, D. intricatus, and Samanea saman. Samples of soil (0-10 cm depth) and rice were collected at 3 positions (1, 5-7, and 9-11 m) away from the tree base in 3 replicated tree-soil trasects in each paddy field. Significantly higher pH, organic matter, and nutrients (N, P, K, Ca, and Mg) were found in paddy fields with S. saman (a legume tree) but grain yield and biomass of rice were significantly lower. Higher soil fertility was found in the positions closer to tree base while grain yields, biomass, and number of tillers were lower, and rice was taller and had more unfilled grain. Shading was deduced to be the key factor responsible for the depressed rice yields and growth at positions closer to tree base especially in the highly shading S. saman.

}, keywords = {minerals, northeast Thailand, paddy, rice, soil fertility, trees}, doi = {10.1007/BF00123318}, url = {https://doi.org/10.1007/BF00123318}, author = {S. Sae-Lee and P. Vityakon and B. Prachaiyo} } @article {566, title = {For a determined farmer, agroforestry brings an unexpected reward}, journal = {Agroforestry Today (Kenya)}, volume = {3}, year = {1991}, month = {July-Sept. 1991}, pages = {4-5}, abstract = {This document looks at the agroforestry efforts of George Nti{\textquoteright}Gitonga, a farmer in Kenya{\textquoteright}s Meru District. Since 1967, Mr. Nti{\textquoteright}Gitonga has established over 25,000 trees on his farm which he uses as fodder, food, fuelwood, timber, windbreaks, boundary plantings, erosion control, and maintenance of soil fertility. Also included in this document are Mr. Nti{\textquoteright}Gitonga{\textquoteright}s method for growing his trees in the semi-arid environment, and how he plans on harvesting water for the trees.}, keywords = {agroforestry, fodder, fuelwood, KEFRI, Kenya Forestry Research Institute, soil fertility, timber , trees, water }, author = {Sidney B. Westley and Alice Kaudia} } @article {653, title = {Soil fertility management of paddy fields by traditional farmers in the dry zone of Sri Lanka}, journal = {Journal of Sustainable Agriculture}, volume = {1}, year = {1991}, month = {1991}, pages = {95-106}, abstract = {Traditional farmers in the Dry Zone of Sri Lanka maintained soil fertility of paddy fields for centuries without applying mineral fertilizers. Some of their traditional cultivation practices not only preserved the natural processes which lead to the regeneration of fertility, but also added nutrients to the soil. This study highlights those traditional practices-fallow period, application of green manure and animal waste, aquaculture in paddy fields, utilization of nutrients in irrigation water and planting trees on paddy fields. Why these practices ceased to exist with the introduction of agricultural modernization and increased population is examined herewith.}, keywords = {aquaculture, soil fertility, Sri Lanka}, doi = {10.1300/J064v01n03_08}, url = {http://www.tandfonline.com/doi/abs/10.1300/J064v01n03_08}, author = {Rohana Ulluwishewa} } @article {604, title = {Land-use by immigrant Baoul{\'e} farmers in the Ta{\"\i} region, South-west C{\^o}te d{\textquoteright}Ivoire (Ivory Coast)}, journal = {Agroforestry Systems}, volume = {11}, year = {1990}, month = {1990}, pages = {101-123}, abstract = {

This paper discusses the cropping system of immigrant Baoul{\'e} farmers in the rain-forest area of South-west C{\^o}te d\&$\#$39;Ivoire (Ivory Coast). The area harbours one of the last substantial rain-forest reserves of humid West Africa. Part of it is known as Ta{\"\i} National Park, and has been adopted as one of UNESCO\&$\#$39;s Man and Biosphere Programme areas. The park area is threatened by farmers in search of land. Soils in the area typically show a low intrinsic nutrient content (particularly phosphorus and potassium), low pH values, a low CEC, and, locally, high levels of gravel. In the Baoul{\'e} cropping system fields are kept under perennial crops, mainly cacao, after having been used for food crop cultivation during the first two years. Yam, the most important food crop is grown on mounds. Next to the inherent poverty of the soil, this cropping technique, which disrupts the structure of the top soil is seen as one of the causes for low yields of cocoa on Baoul{\'e} farms in the area. Yields per ha amount to c. 60\% of that of the national average. The conclusion is that the Baoul{\'e} agricultural production system is ill-adapted to the local ecosystem. Measures to improve adaptation include: Introduction of crop species adapted to adverse soil conditions (e.g. rubber, oilpalm), to buffer cacao plantations through planting of shade trees, to apply fertilisers, and to make use of biological nitrogen-fixation. Generally, the remedies proposed involve investments in terms of cash and labour on the part of the farmers. It is argued that farmers will not change their current cropping practices as long as there is forested land in the vicinity. The presence of the Ta{\"\i} forest, c. 300.000 ha of virgin rain-forest, impedes the process of change towards more intensive land-use practices.

}, keywords = {agriculture, cacao, Humid C{\^o}te d{\textquoteright}Ivoire, Ivory Coast, land shortage, soil fertility, transition shifting cultivation, yams}, doi = {10.1007/BF00838724}, url = {http://link.springer.com/article/10.1007/BF00838724}, author = {Arnoud Budelman and Peter M. Zander} } @article {663, title = {Structure and function of traditional agroforestry systems in the western Himalaya. II. Nutrient cycling}, journal = {Agroforestry Systems}, volume = {9}, year = {1989}, month = {August 1989}, pages = {71-89}, abstract = {Budget of nutrient in plant and soil, and their rates of recycling in three types of traditional agroforestry systems in mid elevations of the western Himalaya were studied. Concentration of nitrogen and potassium was significantly higher in fruits and leaves than in branches, boles, and litter. Grewia optiva, an important fodder tree, was found to be rich in potassium, vegetable crops in nitrogen, and weeds in phosphorus. Maximum store of nutrients was estimated in aboveground biomass of agrihortisilvicultural system: nitrogen 532, phosphorus 40, potassium 461, calcium 400, and magnesium 298 kg/ha; it was closely followed by that in agrihorticultural system, and both these had about 2-fold higher nutrient stock as compared to agrisilvicultural system. In the case of the former two systems, considerable quantity of nutrients up to nitrogen 169, phosphorus 14, potassium 165, calcium 97, and magnesium 65 kg/ha, for example in agrihortisilvicultural system, was recycled through debris of crops and weeds, and tree leaf litter, while the recycling rate was almost half in agrisilvicultural system. Through {\textquoteright}harvest{\textquoteright} potassium was depleted in the largest quantity from the system, followed by nitrogen, magnesium, calcium, and phosphorus; much higher loss occurred through agricultural and/or horticultural edible parts as compared to fuel and fodder biomass. For example, the loss through agricultural crops and horticultural fruits for nitrogen in agrihortisilvicultural system was up to 75 percent and 38 percent respectively of the total annual uptake. This heavy loss makes the system unstable from a nutrient point of view particularly for nitrogen and potassium until external inputs are added through organic and inorganic fertilizers. Agrihortisilvicultural system is remarkably efficient in view of biomass productivity for fuel, fodder and fruits, and also from nutrient point of view provided losses through harvest are compensated externally.}, keywords = {agroforestry systems, allocation pattern, nutrient budget, nutrient cycling, soil fertility, Western Himalaya}, doi = {10.1007/BF00120156}, url = {https://doi.org/10.1007/BF00120156}, author = {Om Parkash Toky and Pradeep Kumar and Prem Kumar Khosla} } @inbook {869, title = {Elements of success: Sustainable development in sub-Saharan Africa}, booktitle = {World Resources 1987: An assessment of the resource base that supports the global economy}, year = {1987}, note = {Chapter 14}, month = {April 1987}, pages = {221-238}, publisher = {Basic Books}, organization = {Basic Books}, address = {Washington, DC}, abstract = {In recent years, Africa{\textquoteright}s farmers and herders, its soils and forests, have been chasing each other down a vicious spiral of environmental degradation and deepening poverty. Conventional development efforts by donors and governments have largely failed to halt the spiral, indeed in some cases have aggravated it. The need to find solutions is urgent. Africa not only must increase its energy and found output in line with rapidly expanding populations, but must do so in a way that preserves the resource base and enhances the welfare and income of the majority. Despite the general landscape of failure, a growing number of projects and programs -- governmental, intergovernmental, and nongovernmental -- have succeeded. This chapter examines some of those "success stories" and attempts to draw some more general lessons that can point to a "recipe for success" in sub-Saharan Africa.}, keywords = {agroforestry, alley cropping, Burkina Faso, cassava, charcoal , drought, fuelwood, green revolution, Kenya, maize, Niger, Nigeria, OXFAM, rainfall, reforestation, soil fertility, stoves, trypanosomiasis, water conservation, windbreaks, Zimbabwe}, isbn = {0-465-09239-X}, url = {https://www.wri.org/publication/world-resources-1987}, author = {International Institute for the Environment and Development (IIED) and World Resourses Institute (WRI)} } @book {364, title = {Man and tree in tropical Africa: Three essays on the role of trees in the African environment}, year = {1978}, month = {1978}, pages = {31}, publisher = {International Development Research Centre}, organization = {International Development Research Centre}, address = {Ottawa, ON, Canada}, abstract = {

Contains following essays:

The first paper examines, in general, the role of the tree in tropical Africa. Highlighted are the variety of products that can be obtained from the forests, the vital role of trees in nutrient cycling and in soil and water conservation, and their influence on both micro and macroclimate. The second essay addresses the ever important question of wood-fuel supplies. With increasing petroleum prices, greater demands than ever before are being placed on wood, and with decreasing supplies prices are rising. Wood-fuel shortages have led to a switch to other fuel sources such as manure and crop residues, which has in turn started a vicious circle of decreasing crop yields and environmental degradation. The final essay examines the age-old practice of shifting cultivation. Suggestions advanced here for tailoring new ideas to this traditional practice may well make it possible to modify or improve the system to meet modern realities. Methods involving zero tillage and the use of trees as \&$\#$39;nutrient pumps\&$\#$39; seem to offer particular promise in this regard.

}, keywords = {agroforestry, erosion control, fuelwood, soil erosion, soil fertility}, isbn = {0-88936-154-1; 978-0-88936-154-6}, url = {http://www.worldcat.org/oclc/5510947}, author = {Gunnar Poulsen} }