نتایج جستجو برای: soil water uniformity
تعداد نتایج: 705692 فیلتر نتایج به سال:
Long-term trends of the combined effects of evapotranspiration and precipitation effect surface hydrology and soil water and consequently natural and agricultural ecosystems. This paper analyses yield index and soil water deficit time series derived from water balance calculations for multiple cropping systems with FAO methodology. The analysis shows that yield index values have increased and s...
Duke et al. (1970) developed a mercury manometer and electrode-based controller for a soil water sampler A vacuum applied to soil water percolation samplers permits collecsystem. When coupled with a soil tensiometer, the detion of both macroand matrix-pore liquids. Performance of these field samplers is improved when the extraction vacuum is adjusted in vice automatically adjusted vacuum levels...
Great attention has been paid to the potential of wastewater irrigation as a sustainable water source, particularly due to water scarcity and water pollution issues. However, few studies have focused on its adverse effects and on the health risks it may pose. In this study, the physicochemical properties of soils and plants irrigated with rural domestic wastewater and associated microbiological...
Many of the yellow earths in the Western Australian wheatbelt have naturally acidic subsoils which can reduce the yield of wheat grown on them. Current methods of assessing soil acidity cannot identify which soils have subsoil acidity severe enough to restrict wheat yields. We conducted 53 field experiments at 34 sites in 5 regions over 3 years to determine the relationship between yield of whe...
Laboratory experiments were conducted to evaluate adsorption, desorption and mobility of metsulfuron-methyl in soils of the oil palm agroecosystem consisting of the Bernam, Selangor, Rengam and Bongor soil series. The lowest adsorption of metsulfuron-methyl occurred in the Bongor soil (0.366 ml g(-1)), and the highest in the Bemam soil (2.837 ml g(-1). The K(fads) (Freundlich) values of metsulf...
Water is a limiting factor for plant growth and vegetation dynamics in alpine sandy land of the Tibetan Plateau, especially with the increasing frequency of extreme precipitation events and drought caused by climate change. Therefore, a relatively stable water source from either deeper soil profiles or ground water is necessary for plant growth. Understanding the water use strategy of dominant ...
Manganese (Mn) contamination of drinking water may cause aesthetic and human health problems when concentrations exceed 50 and 500 μg l, respectively. In the UK, the majority of Mn-related drinking water supply failures originate from unpolluted upland catchments. The source of Mn is therefore soil, but the exact mechanisms by which it is mobilised into surface waters remain unknown. Elevated M...
BACKGROUND Monitoring the properties of dissolved organic carbon (DOC) in soil water is frequently used to evaluate changes in soil quality and to explain shifts in freshwater ecosystem functioning. METHODS Using >700 individual soils (0-15 cm) collected from a 209,331 km(2) area we evaluated the relationship between soil classification (7 major soil types) or vegetation cover (8 dominant cla...
Definitions and forms of salinity All natural waters contain soluble salts. The concentration of the salts determines whether the water is of high quality (drinkable or usable for irrigation without need for special precautions) or of low quality (brackish or saline). Water in the soil also contains soluble salts (sometimes called free or nonattached salts). The amount of salts in the root zone...
Freshwater resources in the North China Plain (NCP) are near depletion due to the unceasing overexploitation of deep groundwater, by far the most significant source of freshwater in the region. To deal with the deepening freshwater crisis, brackish water (rich but largely unused water in agriculture) is increasingly being used in irrigation in the region. However, inappropriate irrigation with ...
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