Your search found 4 records
1 Wetzelhuetter, C. (Ed.) 2013. Groundwater in the coastal zones of Asia-Pacific. Dordrecht, Netherlands: Springer. 382p. (Coastal Research Library Volume 7)
Coastal area ; Hydrogeology ; Models ; Salt water intrusion ; Aquifers ; Sea level ; Groundwater development ; Groundwater management ; Ecosystems ; NMR spectroscopy ; Geochemistry ; Chemical control ; Water quality ; Case studies / Asia-Pacific / China / USA / Hawaii / India / Australia / Thailand / Malaysia / New Zealand / United Arab Emirates / Hainan / Andhra Pradesh / West Bengal / Oahu / Eyre Peninsula / Songkhla / Uley Basin / Willunga Basin / Manukan Island / Kapas Island / Godavari Delta / Carnarvon / Gascoyne River / Yanzhoy River / Sanjiang River / Yanfeng River / Xi River / Wadi Ham Aquifer / Cook Islands / Pukapuka Atoll
(Location: IWMI HQ Call no: 551.457 G570 WET Record No: H046324)
(0.31 MB)
2 Li, H.; Xia, Y.; Geng, X. 2013. Hydrogeology and hydrochemistry along two transects in mangrove tidal marshes at Dongzhaigang National Nature Reserve, Hainan, China. In Wetzelhuetter, C. (Ed.). Groundwater in the coastal zones of Asia-Pacific. Dordrecht, Netherlands: Springer. pp.11-25. (Coastal Research Library Volume 7)
Hydrogeology ; Geochemistry ; Mangroves ; Nature reserves ; Water table ; Water quality ; Ecosystems ; Rivers ; Wells ; Salinity / China / Hainan / Yanzhoy River / Sanjiang River / Yanfeng River / Xi River
(Location: IWMI HQ Call no: 551.457 G570 WET Record No: H046326)
Dongzhaigang National Nature Reserve is the largest mangrove forest nature reserve in China, holds the most abundant mangrove species, and has been giving the best preservation. However, bald mud beaches were found among the mangrove marshes in the reserve. In order to investigate the environmental characteristics behind this phenomenon, the intertidal zones of a mangrove transect and a bald beach transect with similar topography and tidal actions were selected for comparison study. Several monitoring wells were installed along the two transects for in-situ measurements of pH, ORP, salinity and temperature of groundwater. Groundwater samples were collected for lab analysis as well. The results showed that pH values of the mangrove transect were higher than that of the bald beach transect, ORP measurements indicated that the mangrove transect had an oxidizing environment and the bald beach transect has a reducing environment. Lab analysis showed that the concentrations of anions (Cl-, SO4 2-, Br-) and cations (K+, Na+, Ca2+, Mg2+) of water sampled from the bald each transect were much higher than that of the mangrove beach transect. Along both transects, observed water table variations were significant in the high and low intertidal zones and negligible in the middle intertidal zones. The observed groundwater salinity was significantly smaller along the mangrove transect than along the bald beach transect. Previously published analysis concluded that the two transects have a mud-sand two-layered structure: a surface zone of low-permeability mud and an underlying high-permeability zone that outcrops at the high and low tide lines. The freshwater recharge from inland is considerable along the mangrove transect but negligible along the bald beach transect, this may explain the lower concentrations of salt and regular ions along the mangrove transect than along the bald beach transect. This comparative study of hydrogeology and hydrochemistry along the two transects would provide ecological implications on the restoration, protection and management of mangrove ecosystems.
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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