Your search found 19 records
1 Noble, Andrew D.; Ruaysoongnern, S.; Penning de Vries, Frits W. T.; Hartmann, C.; Webb, M. J. 2004. Enhancing the agronomic productivity of degraded soils in Northeast Thailand through clay-based interventions. In Seng, V.; Craswell, E.; Fukai, S.; Fischer, K. (Eds.), Water in agriculture: Proceedings of a CARDI International Conference “Research on Water in Agricultural Production in Asia for the 21st Century” Phnom Penh, Cambodia, 25-28 November 2003. Canberra, Australia: ACIAR. pp.147-160.
(Location: IWMI-HQ Call no: 631.7.2 G000 SEN, IWMI 631.4 G750 NOB Record No: H032797)
2 Simmons, Robert; Noble, Andrew D.; Lefroy, R. D. B. (Eds.) 2001. International Workshop on Nutrient Balances for Sustainable Agricultural Production and Natural Resource Management in Southeast Asia, Bangkok, Thailand, 20-22 February 2001: selected papers and presentations. Bangkok, Thailand: IWMI; CIAT. 1 CD.
Soil management ; Soil properties ; Soil fertility ; Soil degradation ; Crop production ; Farmers ; Agricultural extension ; Farming systems ; Sustainability ; Rice ; Cassava ; Vegetables ; Maize ; Fertilizers ; Decision support tools ; Economic aspects / South East Asia / Thailand / Laos / Vietnam / Philippines
(Location: IWMI-HQ Call no: CD Col Record No: H036278)
3 Tipraqsa, P.; Craswell, E. T.; Noble, Andrew D.; Schmidt-Vogt, D. 2007. Resource integration for multiple benefits: Multifunctionality of integrated farming systems in Northeast Thailand. Agricultural Systems, 94:694-703.
Rainfed farming ; Irrigated farming ; Farming systems ; Farms ; Households ; Surveys / Thailand / Khon Kaen Province / Waeng Yai District / Chonnabot District / Huai Nong Ian Catchment
(Location: IWMI HQ Call no: IWMI 630 G750 TIP Record No: H040587)
(0.37 MB)
Resource degradation in rice farming systems in Thailand endangers food security, but the systems may become more sustainable by combining them with aquaculture and livestock farm enterprises by capitalization of their synergies in resource use and re-use, i.e. by adopting integrated farming systems. Most empirical studies that assess this potential have focused on a few specific aspects, but not on the multiple social, economic, and ecological functions of resource integration. This study uses the framework of multifunction agriculture to assess the performance of integrated farming systems in Thailand and compares its performance with that of ‘normal-rice’ or non-integrated farming systems. Surveys were conducted in Khon Kaen province of Northeast Thailand using a combination of quantitative and qualitative survey methods. Integrated farming systems were found to outperform the normal or commercial farming systems in all four dimensions of a multifunctional agriculture: food security, environmental functions, economic functions, and social functions. The findings support the notion that diversification and integration of resources on farms is feasible in both economic and ecological terms. The analyses shows that integrated farming does not, however, diminish the need for external inputs. High start-up cost might constrain farmers from switching to integrated farming and from exploiting the benefits of resource integration.
4 Simmons, Robert W.; Noble, Andrew D.; Pongsakul, P.; Sukreeyapongse, O.; Chinabut, N. 2009. Cadmium-hazard mapping using a general linear regression model (Irr-Cad) for rapid risk assessment. Environmental Geochemistry and Health, 31(1):71-79. [doi: https://doi.org/10.1007/s10653-008-9157-x]
Rice ; Soyabeans ; Cadmium ; Zinc ; Health hazards ; Risks ; Assessment ; Irrigated farming ; Models ; Soil analysis / Japan / China / Thailand / Vietnam / Myanmar / Laos
(Location: IWMI HQ Call no: e-copy only Record No: H040619)
(0.37 MB)
5 Hartmann, C.; Poss, R.; Noble, Andrew D.; Jongskul, A.; Bourdon, E.; Brunet, D.; Lesturgez, G. 2008. Subsoil improvement in a tropical coarse textured soil: effect of deep-ripping and slotting. Soil and Tillage Research, 99(2):245-253.
(Location: IWMI HQ Call no: IWMI 633.15 G750 HAR Record No: H041505)
6 Noble, Andrew D.; Bossio, Deborah; Pretty, J.; Penning de Vries, F. 2008. Bright spots: pathways to ensuring food security and environmental integrity. In Bossio, Deborah; Geheb, Kim (Eds.). Conserving land, protecting water. Wallingford, UK: CABI; Colombo, Sri Lanka: International Water Management Institute (IWMI); Colombo, Sri Lanka: CGIAR Challenge Program on Water & Food. pp.191-204. (Comprehensive Assessment of Water Management in Agriculture Series 6)
(Location: IWMI HQ Call no: IWMI 631.7 G000 BOS Record No: H041602)
7 Bossio, Deborah; Noble, Andrew D.; Aloysius, Noel; Pretty, J.; Penning de Vries, F. 2008. Ecosystem benefits of ‘bright’ spots. In Bossio, Deborah; Geheb, Kim (Eds.). Conserving land, protecting water. Wallingford, UK: CABI; Colombo, Sri Lanka: International Water Management Institute (IWMI); Colombo, Sri Lanka: CGIAR Challenge Program on Water & Food. pp.205-224. (Comprehensive Assessment of Water Management in Agriculture Series 6)
Crop production ; Poverty ; Public health ; Ecosystems ; Water productivity ; Pesticides ; Rice ; Farming systems ; Shifting cultivation ; Irrigated farming ; Social aspects ; Case studies / China / Uzbekistan / Ethiopia / Ghana / Brazil / India / Honduras / Thailand
(Location: IWMI HQ Call no: IWMI 631.7 G000 BOS Record No: H041603)
8 Saleth, Rathinasamy Maria; Inocencio, Arlene; Noble, Andrew D.; Ruaysoongnern, S. 2009. Economic gains of improving soil fertility and water holding capacity with clay application: the impact of soil remediation research in northeast Thailand. Colombo, Sri Lanka: International Water Management Institute (IWMI). 30p. (IWMI Research Report 130) [doi: https://doi.org/10.3910/2009.130]
Soil improvement ; Impact assessment ; Research projects ; Soil fertility ; Sandy soils ; Water holding capacity ; Clay soils ; Soil water relations ; Soil management ; Farming systems ; Crop yield ; Vegetable crops ; Rice ; Sorghum ; Models ; Statistical methods ; Cost benefit analysis ; Economic analysis ; Economic aspects / Thailand
(Location: IWMI HQ Call no: IWMI 631.422 G750 SAL Record No: H042267)
(427 KB)
Declining productivity of agricultural soils in Northeast Thailand is a challenge facing land managers and farmers. A program was initiated in 2002 to investigate the potential role of incorporating clay-based materials into degraded soils as a means of enhancing productivity. This research report attempts to provide an ex-post assessment of the field level impact and economic viability of this approach, using the empirically derived estimates of the average income impacts that the application of bentonite or clay technology has generated among farm communities in Northeast Thailand. From an exclusive IWMI perspective, the impact evaluation suggests that the program has a net present value (NPV) of US$0.41 million with a benefit-cost ratio (BCR) of 2.44 for the sample, and a NPV of US$21 million with a BCR of 75 for the region.
9 Saleth, Rathinasamy Maria; Inocencio, A.; Noble, Andrew D.; Ruaysoongnern, S. 2009. Economic gains of improving soil fertility and water holding capacity with clay application: the impact of soil remediation research in northeast Thailand. Journal of Development Effectiveness, 1(3):336-352. [doi: https://doi.org/10.1080/19439340903105022]
Bentonite ; Clay soils ; Farming systems ; Impact assessment ; Water holding capacity ; Soil water relations ; Soil management ; Crop yield ; Vegetable crops ; Rice ; Sorghum ; Models ; Statistical methods ; Cost benefit analysis ; Economic analysis / Thailand
(Location: IWMI HQ Call no: e-copy only Record No: H034809)
(0.42 MB)
Using survey data collected from 250 farmers, this paper evaluates the impact of the Soil Remediation Research Project (SRRP) undertaken by International Water Management Institute (IWMI) in Northeast Thailand during 2002–2005. SRRP has demonstrated and promoted the application of clay as a quick and low-cost means for improving the fertility and water holding capacity of sandy soils. The impact evaluation suggests that the SRRP has a net present value (NPV) of US$0.7 million with a benefit–cost ratio (BCR) of 3.1 for the sample context and an NPVof US$99.5 million with a BCR of 317.7 for the larger context of the region.
10 Johnston, Robyn M.; Hoanh, Chu Thai; Lacombe, Guillaume; Noble, Andrew D.; Smakhtin, Vladimir; Suhardiman, Diana; Kam, Suan Pheng; Choo, P. S. 2009. Scoping study on natural resources and climate change in Southeast Asia with a focus on agriculture. Final report. Vientiane, Laos: International Water Management Institute (IWMI) South East Asia Office, for Swedish International Development Cooperation Agency (Sida) 107p. [doi: https://doi.org/10.3910/2010.201]
Climate change ; Natural resources ; Environmental effects ; Agroecology ; Agricultural production ; Crops ; Cropping systems ; Farming systems ; Livestock ; Fisheries ; Food security ; Water management ; Economic aspects ; Rural poverty ; Policy ; Nutrient management / South East Asia / Cambodia / Laos / Thailand / Vietnam / Myanmar / China / Greater Mekong Subregion / Tonle Sap / Yunnan
(Location: IWMI HQ Call no: e-copy only Record No: H042414)
(3.26 MB) (3.26 MB)
11 Hoanh, Chu Thai; Szuster, B. W.; Kam, S. P.; Ismail, A. M; Noble, Andrew D.. (Eds.) 2010. Tropical deltas and coastal zones: food production, communities and environment at the land-water interface. Wallingford, UK: CABI; Colombo, Sri Lanka: International Water Management Institute (IWMI); Penang, Malaysia: WorldFish Center; Los Banos, Philippines: International Rice Research Institute (IRRI); Bangkok, Thailand: FAO Regional Office for Asia and the Pacific; Colombo, Sri Lanka: CGIAR Challenge Program on Water and Food (CPWF). 477p. (Comprehensive Assessment of Water Management in Agriculture Series 9)
Aquaculture ; Fisheries ; Rice ; Coastal area ; Cropping systems ; Salinity ; Food production ; Food security / South East Asia / Vietnam / Philippines / Bangladesh / Thailand / India / Indonesia / Sri Lanka / West Africa / Brazil
(Location: IWMI HQ Call no: IWMI 551.457 G000 HOA Record No: H043045)
(5.08 MB)
12 Szuster, B.; Hoanh, Chu Thai; Kam, S. P.; Ismail, A. M.; Noble, Andrew D.; Borger, M. 2010. Policy, planning and management at the land-water interface. In Hoanh, Chu Thai; Szuster, B. W.; Kam S. P.; Ismail, A. M; Noble, Andrew D. (Eds.). Tropical deltas and coastal zones: food production, communities and environment at the land-water interface. Wallingford, UK: CABI; Colombo, Sri Lanka: International Water Management Institute (IWMI); Penang, Malaysia: WorldFish Center; Los Banos, Philippines: International Rice Research Institute (IRRI); Bangkok, Thailand: FAO Regional Office for Asia and the Pacific; Colombo, Sri Lanka: CGIAR Challenge Program on Water and Food (CPWF). pp.1-12. (Comprehensive Assessment of Water Management in Agriculture Series 9)
Coastal area ; Land management ; Water management ; Shrimp culture ; Rice ; Salinity ; Sluices ; Households ; Income generation ; Climate change / Bangladesh / India / Vietnam / Thailand
(Location: IWMI HQ Call no: IWMI 551.457 G000 HOA Record No: H043046)
http://www.iwmi.cgiar.org/Publications/CABI_Publications/CA_CABI_Series/Coastal_Zones/protected/9781845936181.pdf
https://vlibrary.iwmi.org/pdf/H043046.pdf
https://vlibrary.iwmi.org/pdf/H043046.pdf
(0.20 MB) (5.08 MB)
13 Johnston, Robyn M.; Lacombe, Guillaume; Hoanh, Chu Thai; Noble, Andrew D.; Pavelic, Paul; Smakhtin, Vladimir; Suhardiman, Diana; Kam, S. P.; Choo, P. S. 2010. Climate change, water and agriculture in the Greater Mekong subregion. Colombo, Sri Lanka: International Water Management Institute (IWMI). 52p. (IWMI Research Report 136) [doi: https://doi.org/10.5337/2010.212]
Climate change ; Adaptation ; Indicators ; Water resource management ; River basins ; Water availability ; Water quality ; Groundwater ; Fisheries ; Ecosystems ; Water power ; Population growth ; Land use ; Biofuels ; Sea level / South East Asia / Cambodia / Laos / Myanmar / Thailand / Vietnam / China / Greater Mekong Subregion / Yunnan Province
(Location: IWMI HQ Call no: IWMI 333.91 G800 JOH Record No: H043300)
(683.10 KB)
The impacts of climate change on agriculture and food production in Southeast Asia will be largely mediated through water, but climate is only one driver of change. Water resources in the region will be shaped by a complex mixture of social, economic and environmental factors. This report reviews the current status and trends in water management in the Greater Mekong Subregion; assesses likely impacts of climate change on water resources to 2050; examines water management strategies in the context of climate and other changes; and identifies priority actions for governments and communities to improve resilience of the water sector and safeguard food production.
14 Qadir, Manzoor; Quillerou, E.; Nangia, V.; Murtaza, G.; Singh, M.; Thomas, R. J.; Drechsel, Pay; Noble, Andrew D.. 2014. Economics of salt-induced land degradation and restoration. Natural Resources Forum, 38:282-295. [doi: https://doi.org/10.1111/1477-8947.12054]
Land degradation ; Land reclamation ; Land reform ; Soil salinity ; Economic aspects ; Costs ; Irrigated land ; Crop yield
(Location: IWMI HQ Call no: e-copy only Record No: H046675)
(0.14 MB)
Food security concerns and the scarcity of new productive land have put productivity enhancement of degraded lands back on the political agenda. In such a context, salt-affected lands are a valuable resource that cannot be neglected nor easily abandoned even with their lower crop yields, especially in areas where significant investments have already been made in irrigation and drainage infrastructure. A review of previous studies shows a very limited number of highly variable estimates of the costs of salt-induced land degradation combined with methodological and contextual differences. Simple extrapolation suggests that the global annual cost of salt-induced land degradation in irrigated areas could be US$ 27.3 billion because of lost crop production. We present selected case studies that highlight the potential for economic and environmental benefits of taking action to remediate salt-affected lands. The findings indicate that it can be cost-effective to invest in sustainable land management in countries confronting salt-induced land degradation. Such investments in effective remediation of salt-affected lands should form part of a broader strategy for food security and be defined in national action plans. This broader strategy is required to ensure the identification and effective removal of barriers to the adoption of sustainable land management, such as perverse subsidies. Whereas reversing salt-induced land degradation would require several years, interim salinity management strategies could provide a pathway for effective remediation and further showcase the importance of reversing land degradation and the rewards of investing in sustainable land management.
15 Qadir, M.; Noble, Andrew D.; Karajeh, F.; George, B. 2015. Potential business opportunities from saline water and salt-affected land resources. Colombo, Sri Lanka: International Water Management Institute (IWMI). CGIAR Research Program on Water, Land and Ecosystems (WLE). 29p. (Resource Recovery and Reuse Series 05) [doi: https://doi.org/10.5337/2015.206]
Land resources ; Land degradation ; Saline water ; Sodic soils ; Soil salinity ; Desalination ; Crop production ; Ecosystems ; Aquaculture ; Water resources ; Water productivity ; Drainage water ; Water reuse ; Recycling ; Freshwater ; Soil properties ; Magnesium ; Phosphogypsum ; Energy generation ; Solar energy ; Horticulture ; Greenhouses ; Irrigation ; Deltas ; Trees ; Case studies / Egypt
(Location: IWMI HQ Call no: IWMI Record No: H046996)
(1 MB)
16 Noble, Andrew D.; Berthelsen, S.; Mather, J. 2005. Changes in soil chemical properties under two contrasting plantation systems on the Zululand coastal plain, South Africa. In International Union of Soil Sciences (IUSS); Institut de Recherche pour le Developpement (IRD); Thailand. Land Development Department (LDD); International Water Management Institute (IWMI); FAO. Regional Office for Asia and the Pacific (FAO RAP); Khon Kaen University. Faculty of Agriculture. Management of tropical sandy soils for sustainable agriculture: a holistic approach for sustainable development of problem soils in the tropics. Proceedings of the First Symposium on Management of Tropical Sandy Soils for Sustainable Ariculture, Khon Kaen, Thailand, 27 November – 2 December 2005. Bangkok, Thailand: FAO Regional Office for Asia and the Pacific (FAO RAP). pp.93-100.
Soil properties ; Soil chemicophysical properties ; Soil profiles ; Plantations ; Species ; Eucalyptus grandis ; Pinus elliottii ; Podzols ; Organic carbon ; Coastal plains / South Africa / Zululand Coastal Plain
(Location: IWMI HQ Call no: 630 G000 INT Record No: H047324)
(0.39 MB) (16.9 MB)
Over the past 4 decades there has been considerable expansion in the plantation forestry along the eastern seaboard of South Africa. In particular there have been significant increases in eucalypt, and to a less extent, pine plantations on soils of a light sandy texture along the Zululand coastal plain. These soils are characteristically dominated by sands with low clay and organic matter contents, have low cation exchange capacity and water holding capacity. Pedogenesis and selected chemical attributes of a 49-year-old stand of Eucalyptus grandis and Pinus elliottii established on these sands were compared. Changes in soil pH, exchangeable cations, organic carbon, extractable Fe and Al and the surface charge characteristics were investigated. Evidence of the development of bleached A2e horizon within the surface 0-5 cm depth interval under E. grandis was confirmed through the development of surface charge fingerprints, changes in organic carbon and Fe and Al mobilization for each of the pedogenetically distinct horizons. Such development was not observed under the P. elliottii stand, suggesting that this pine species has had less impact on the soil. It is argued that the rate of A2e horizon development is not dissimilar to that observed under native forest ecosystems in Australia, although considerably slower that those observed under reclaimed sand mining operations. Whilst these systems appear to be relatively stable due to no clear felling and timber product extraction, this could drastically change with the introduction of short-term rotations of fast growing clonal plantations, questioning the long-term sustainability of these production systems on these light textured sands.
17 Armour, J. D.; Berthelsen, S.; Ruaysoongnern, S.; Moody, P. W.; Noble, Andrew D.. 2005. Remediation of soil acidification by form of nitrogen fertilizer on grass swards of Australia and Thailand. In International Union of Soil Sciences (IUSS); Institut de Recherche pour le Developpement (IRD); Thailand. Land Development Department (LDD); International Water Management Institute (IWMI); FAO. Regional Office for Asia and the Pacific (FAO RAP); Khon Kaen University. Faculty of Agriculture. Management of tropical sandy soils for sustainable agriculture: a holistic approach for sustainable development of problem soils in the tropics. Proceedings of the First Symposium on Management of Tropical Sandy Soils for Sustainable Ariculture, Khon Kaen, Thailand, 27 November – 2 December 2005. Bangkok, Thailand: FAO Regional Office for Asia and the Pacific (FAO RAP). pp.135-139.
Soil profiles ; Acidification ; Grasses ; Pastures ; Species ; Cropping systems ; Nitrogen fertilizers ; Soil pH ; Alkalinity ; Acrisols / Australia / Thailand / Mareeba / Tully / Chiang Yuen
(Location: IWMI HQ Call no: 630 G000 INT Record No: H047325)
(0.36 MB) (16.9 MB)
Acidification of soil profiles from legume and N fertilized crops is a serious sustainability threat. Under tropical conditions of Northeast Thailand and Northern Australia, acidification to >90 cm has been recorded in Stylosanthes and Leucaena based pasture systems. Acidification has also been measured in other Australian cropping systems fertilized with urea or ammonium forms of N. The major processes contributing to what could be termed anthropogenic acidification are removal of base cations in the harvested product and leaching below the root zone of nitrate from ammonium and urea N fertiliser or legumes resulting in an accumulation of protons in surfaces horizons. If prophylactic applications of lime are not undertaken, acid generation in surface horizons will progressively move down the profile inducing subsoil acidification. Subsoil acidity is often difficult to correct using conventional applications of liming products. Field experiments with pastures on Acrisols in Northeast Australia (two sites) and Northeast Thailand (one site) compared the rates of alkalisation or acidification from N applied as nitrate or as urea (Australia) or ammonium sulphate (Thailand). Soil pH increased where N was applied as nitrate and decreased where N was applied as urea or ammonium sulphate. At one of the sites in Australia, regular applications of N as nitrate at 350 kg N ha-1 year-1 were made to irrigated Digitaria melanjiana cv Jarra. This significantly increased soil pH (1:5 0.01 M CaCl2) by up to 0.5 units to a depth of 0.90 m over a period of 4 years when compared to bare soil. The alkalisation of the profile was equivalent to 2.7 t/ha of calcium carbonate distributed evenly down the profile. Urea at the same rate of N decreased soil pH at 20-50 cm by 0.2 units. Similar but smaller changes were measured at the other Australian site (Brachiaria decumbens) and the site in Thailand (Andropogon gayanus cv Carimagua (Gamba grass). Treatment effects at these sites were restricted by time (1 year) or seasonal conditions that limited the number of N applications that could be applied (290 kg N/ha over 3 years) at the Thai site. The research has clearly demonstrated that nitrate N fertilizer can rapidly correct soil acidity down the soil profile to 0.9 m and this is attributed to the release of alkali from roots as nitrate is taken up. Such a strategy may be an effective approach to addressing subsoil acidification where surface applications of lime are ineffective and profile modification is cost prohibitive.
18 Soda, W.; Noble, Andrew D.; Suzuki, S.; Simmons, R.; Sindhusen, L.; Bhuthorndharaj, S. 2005. The co-composting of waste bentonites from the processing of vegetable oil and its affect on selected soil properties of a light textured sand. In International Union of Soil Sciences (IUSS); Institut de Recherche pour le Developpement (IRD); Thailand. Land Development Department (LDD); International Water Management Institute (IWMI); FAO. Regional Office for Asia and the Pacific (FAO RAP); Khon Kaen University. Faculty of Agriculture. Management of tropical sandy soils for sustainable agriculture: a holistic approach for sustainable development of problem soils in the tropics. Proceedings of the First Symposium on Management of Tropical Sandy Soils for Sustainable Ariculture, Khon Kaen, Thailand, 27 November – 2 December 2005. Bangkok, Thailand: FAO Regional Office for Asia and the Pacific (FAO RAP). pp.204-214.
Composting ; Bentonite ; Plant oils ; Waste treatment ; Bleaching ; Litter for animals ; Rice husks ; Soil properties ; Soil chemicophysical properties ; Acidity ; Porosity ; Pot experimentation / Thailand / Bangkok
(Location: IWMI HQ Call no: 630 G000 INT Record No: H047327)
(0.59 MB) (16.9 MB)
Waste acid bentonite is a byproduct from vegetable oil bleaching that is both acidic (pH <3.0) and water repellent (hydrophobic). These materials are currently disposed in landfills and are an environmental hazard due to the aforementioned properties. A study was undertaken using three different sources of waste oil bentonites collected from processing plants within the Bangkok metropolitan area. These wastes included soybean oil bentonite (SB), palm oil bentonite (PB) and rice bran oil bentonite (RB), each of which was co-composted with rice husk, rice husk ash, and chicken litter in order to eliminate their acid reactivity and hydrophobic nature. The chemical and physical characteristics of acid activated bentonites before and after bleaching and the co-composted materials after addition to a degraded light textured soil were assessed and are reported herein. The organic carbon (OC) content, pH, exchangeable cations and cation exchange capacity (CEC) of the waste oil bentonites increased significantly after the co-composting phase. In addition, the hydrophobic nature of these materials as measured using the Water Drop Penetration Test (WDPT) decreased from 10,800 seconds to 16-80 seconds after composting. Furthermore, when these composted materials were incorporated into a degraded light textured sandy soil positive impacts to soil physical attributes in terms of specific surface area, total porosity and available water content for crop growth were observed. The results from this study demonstrate the positive impact of the waste products when modified through composting on the physical and chemical properties of a light textured sandy soil.
19 Berthelsen, S.; Noble, Andrew D.; Ruaysoongnerm, S.; Webb, M.; Hengfu, H.; Jiexiang, Y. 2005. Addition of clay based soil ameliorants to light textured soils to reduce nutrient loss and increase crop productivity. In International Union of Soil Sciences (IUSS); Institut de Recherche pour le Developpement (IRD); Thailand. Land Development Department (LDD); International Water Management Institute (IWMI); FAO. Regional Office for Asia and the Pacific (FAO RAP); Khon Kaen University. Faculty of Agriculture. Management of tropical sandy soils for sustainable agriculture: a holistic approach for sustainable development of problem soils in the tropics. Proceedings of the First Symposium on Management of Tropical Sandy Soils for Sustainable Ariculture, Khon Kaen, Thailand, 27 November – 2 December 2005. Bangkok, Thailand: FAO Regional Office for Asia and the Pacific (FAO RAP). pp.373-382.
Soil texture ; Soil fertility ; Soil chemicophysical properties ; Soil organic matter ; Clay soils ; Sandy soils ; Cation exchange capacity ; Bentonite ; Plant water relations ; Agricultural production ; Productivity ; Rice ; Yields ; Farmers ; Biomass / Northern Australia / Northeast Thailand / China / Hainan
(Location: IWMI HQ Call no: 630 G000 INT Record No: H047329)
(0.46 MB) (16.9 MB)
Productivity decline occurs in many agronomic systems due to loss of soil organic matter and a consequent decline in soil fertility. This is pronounced in light textured soils, which even in their pristine state can have low levels of fertility. High temperatures and leaching conditions in tropical environments further exacerbates this poor fertility. In order to facilitate agronomic production on these soils, significant amounts of organic or inorganic fertilizers are required to maintain economic yields. However, the inherent low cation exchange capacity (CEC) of these soils limits their ability to retain nutrients such as Ca2+, Mg2+ and K+. The addition of inorganic fertilizer is often beyond the means of resource poor farmers and has the potential negative impact on the environment due significant leaching losses associated with the high hydraulic conductivity of light textured sandy soils. This paper reviews results from field experiments designed to assess the efficacy of bentonite (high-activity clay with a high CEC) additions on improving crop productivity and reducing nutrient loss. A number of field trials were established on light-textured soils in Northern Australia, Northeast Thailand and Hainan Province in China. Treatments and crop species (including sugarcane and various forage crops) differed at each of the study locations and included a range of rates (from 10 to 60 t ha-1), different application methods (broadcast, banded and slotted), and in some trials a comparison with other commonly used field amendments (e.g. various organic materials and termite mound material). These field trials demonstrated significant increases in crop biomass and yields associated with clay additions. Additional glasshouse studies support the observed increases in biomass observed in the field trials, and suggest that the yield increases were due to a combination of increased water-holding capacity, nutrient availability and reduced nutrient loss. These results support the notion that degraded light textured soils can be highly productive if intrinsic properties are addressed through clay additions.
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