نتایج جستجو برای: soil water content
تعداد نتایج: 1056794 فیلتر نتایج به سال:
Since rice is a staple food most consumed world-wide, there have been increasing health concerns regarding exposure to arsenic through rice consumption. Several studies have reported the accumulation of arsenic in rice grains cultivated in regions with elevated levels of arsenic in groundwater or contaminated soil. Therefore the principal aim of this study was determining the amount of arsenic ...
BACKGROUND: One of limitation factor in agricultural plants production in dry areas, supply requires water. Also nutrition crop management is a necessary strategy for achieve sustainable agriculture. OBJECTIVES: Current study was conducted to assessment the effects of different irrigation regimes and several amount of nitrogen fertilizer on seed nutrition...
Soil moisture at a horizontal scale of around 700 m and depths of 15 to 70 cm can be inferred from measurements of cosmic-ray neutrons that are generated within soil, moderated mainly by the hydrogen atoms in water, and emitted back to the atmosphere. The intensity of the resulting field of neutrons above the ground is sensitive to water content changes, largely insensitive to soil chemistry an...
The water percolation loss beyond root zone in the soil is one of the important parameters to determine water requirement of rice plant. If the amount of water percolation rate into the soil is estimated more carefully, determination of water requirement will be evaluated better and designing for system of irrigation, drainage and related establishments will be more easily done. The purpose of ...
expansive behavior is usually observed in soils, which contain fractions of clay minerals in their composition. water absorption of clay particles and change of natural water content of soil up to plastic limit and down to shrinkage limit will cause significant volume change in expansive soils and will result in severe damages to the structures, buildings and foundations. swelling potential is ...
Introduction The geotechnical engineering problems involving unsaturated soils are included water flow, shear strength and volume change. Soil-water characteristic curve (SWCC) describes the constitutive relationship between soil suction and soil water content. SWCC may be determined directly or indirectly in the laboratory. Because of the various difficulties involved in the direct measuremen...
A physically based, variably saturated flow model was developed to predict soil water dynamics, evapotranspiration (ET) from the vadose zone, and recharge to (or exfiltration from) the saturated zone using mean daily atmospheric forcings and to identify the value of diurnal climate forcings on those predictions. The vadose zone flow is modelled using the Galerkin finite element technique to sol...
increasing attention has recently been given to sweet sorghum as a renewable raw material for ethanol production, mainly because its cultivation can be fully mechanized. however, the intensive use of agricultural machinery causes soil structural degradation, especially when performed under inadequate conditions of soil moisture. the aims of this study were to evaluate the physical quality of a ...
Many studies of water flow and solute transport in the vadose zone require estimates of the unsaturated soil hydraulic properties, including the soil water retention curve ~WRC! describing the relationship between soil suction and water content. An artificial neural network ~ANN! approach was developed to describe the WRC using observed data from several soils. The ANN approach was found to pro...
Incorporation of crop residues into the soil can reduce its susceptibility to compaction. However, the signi®cance of incorporated crop residue at different soil water contents at the time of compaction and the compaction loads is not well documented. The compactibility of three soils which contained different amounts of sugarcane residue was investigated at different water contents and compact...
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