Your search found 4 records
1 Chemin, Yann; Phuphak, S.; Asilo, S.; Hijmans, R. J. 2012. Determining spatial and temporal patterns of submergence in rice with MODIS satellite data. International Journal of Geoinformatics, 8(2):1-12.
Rice ; Crop management ; Canopy ; Remote sensing ; Satellite surveys ; Surface water ; Flooding ; Drought / Northeast Thailand / Philippines / Nueva Ecija Province
(Location: IWMI HQ Call no: e-copy only Record No: H044965)
(4.28 MB)
Rice submergence is the condition by which the water level rises above the rice crop canopy. In general, rice plant response to submergence is to elongate its shoots above the rising water level. This costs in energy and eventually has a direct impact in terms of reducing yields. A specific gene, called Sub1, when introgressed into popular rice varieties by Marker Assisted Back-crossing, nearly stops the natural elongation process and permits a given local rice variety to sustain submerged conditions for a generally recognized period of about 2 weeks. Plant breeders now look for well-identified and location-accurate submergence areas in order to disseminate such improved local rice varieties. Remote sensing is proposed to provide surface water maps at high temporal resolution, determining a percentage of occurrences of surface water for a given pixel. Occurrence is defined as the count of days of identified surface water within a given period, returned in a percentage on that period. Rice area maps and knowledge of crop calendars are proposed to add to the assessment of submergence prone areas in two study areas, the Northeastern Thailand and Nueva Ecija in North Central Philippines.
2 Hammecker, C.; Maeght, J.-L.; Grunberger, O.; Siltacho, S.; Srisruk, K.; Noble, Andrew. 2012. Quantification and modelling of water flow in rain-fed paddy fields in NE Thailand: evidence of soil salinization under submerged conditions by artesian groundwater. Journal of Hydrology, 456-457:68-78. [doi: https://doi.org/10.1016/j.jhydrol.2012.06.005]
Flow discharge ; Surface water ; Soil water ; Rainfed farming ; Paddy fields ; Saline soils ; Water budget ; Models / Northeast Thailand
(Location: IWMI HQ Call no: e-copy only Record No: H045009)
(1.36 MB)
Water flow and solute transport in soils forms an essential part in many groundwater hydrology studies. This is especially true for Northeast Thailand, where the agricultural land is affected by the soil salinity, which is a widespread and an increasing phenomenon affecting 25% of the agricultural land. Salinization appears as scattered discrete patches of 10–100 m2 in the lowlands, illustrated by white efflorescences during the dry season and bare soil during the cropping season. A field study was undertaken in farm plots to measure the water flow and solute transport within the soil surface and the vadose zone, both inside and outside a saline patch. The water flow was measured on the soil surface with lysimeters and infiltration rings, and was derived in the soil from the hydraulic gradients measured with tensiometers placed at different depths. The salt transport was evaluated with water traps also placed at different depths, where the soil water’s electrical conductivity was measured throughout the rainy season. Field study results demonstrated that the accumulation of saline solutions in rain fed paddy fields, occurred mainly during the rainy season while the soil surface remained flooded. During this period the saline water table rose towards the soil surface independently of infiltration into the soil. It happened in specific places where the compacted soil layer, generally ubiquitous in the area at a depth of 40–50 cm, is interrupted. Therefore salinity appeareds in discret points as patches. Artesian upward flow already described in this area (Haworth et al., 1966; Williamson et al., 1989; Imaizumi et al., 2002) is most probably responsible for this water table rise, thereby affecting crop productivity. Numerical modelling of water flow using HYDRUS-3D further supported these results and showed that managing the depth of flooding within the plot can significantly reduce the outbreak of these saline plumes.
3 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. 2005. 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). 524p.
Soil management ; Sandy soils ; Tropical soils ; Semiarid soils ; Sustainable agriculture ; Poverty ; Food production ; Soil chemicophysical properties ; Planting ; Eucalyptus ; Savannas ; Groundnuts ; Rain ; Farmers ; Farming systems ; Irrigation methods ; Livestock ; Socioeconomic environment ; Clay minerals ; Fertilizers ; Paddy fields ; Water erosion ; Wind erosion ; Case studies ; Hydraulics ; Soil organic matter ; Agroecosystems ; Farm ponds ; Watersheds ; Coastal area ; Infiltration water / Asia / Southern Africa / Eastern Africa / Latin America / Sahel / Northern Burkina Faso / South Africa / West Africa / Cambodia / Vietnam / China / Australia / Malawi / Niger / Guam / Northeast Thailand / Southern Brazil / Ecuador / Hainan / Bình Thuan / Thua Thien Hue / Zululand / Mangodara
(Location: IWMI HQ Call no: 630 G000 INT Record No: H046693)
(16.90 MB) (16.9 MB)
4 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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