نتایج جستجو برای: irrigation efficiencies
تعداد نتایج: 62083 فیلتر نتایج به سال:
the shortage of fresh water and growing competition for clear water makes less water available for agriculture production. the great chalange for the coming decades will be the task of increasing food production with less water, particularly in countries with limited water and land resources. therefore, increasing of irrigation efficienciy and decreasing of water losses are important factores...
Global agricultural production is heavily sustained by irrigation, but irrigation system efficiencies are often surprisingly low. However, our knowledge of irrigation efficiencies is mostly confined to rough indicative estimates for countries or regions that do not account for spatiotemporal heterogeneity due to climate and other biophysical dependencies. To allow for refined estimates of globa...
To minimize movement of tritium into surface waters at the Mixed Waste Management Facility at the Savannah River Site, tritiumcontaminated groundwater released to the surface along seeps in the hillside is being retained in a constructed pond and used to irrigate forest acreage that lies over the contaminated groundwater. Management of the application of tritium-contaminated irrigation water ne...
Sustainability evaluation of the process of water abstraction, distribution, and use for irrigation can contribute to the policy of decision making in irrigation development. Emergy theory and method are used to evaluate a pumping irrigation district in China. A corresponding framework for its emergy evaluation is proposed. Its emergy evaluation shows that water is the major component of inputs...
Abstract An assessment of the human impact on global water cycle requires estimating volume withdrawn for irrigated agriculture. A key parameter in this calculation is irrigation efficiency, which corrects fraction lost between withdrawals and crop due to management, distribution or conveyance losses. Here we show that efficiency used models flawed it overlooks ambiguities partial efficiencies,...
water and nutrient availability are two major constraints to forage maize production in arid and semi-arid areas; however, the effect of different n levels from organic and inorganic sources on nutrient (i.e., n and p) efficiency under drought stress conditions is not well known for maize faming. thus, a field study was conducted with the objective of determining the effect of n fertilization a...
A simulation model was developed to estimate the effect of deficit irrigation upon crop yield. The model was designed to provide relative yield estimates for numerous combinations of irrigation system, crop growth and irrigation management parameters. A daily soil moisture balance was used to predict evaporation and transpiration from which crop yields were estimated. Gross irrigation water req...
drip irrigation is the most efficient technique known for improving irrigation water management. a two-year study was conducted to determine the effects of drip and furrow irrigation methods on yield and quality of sugar beet in north of khuzestan. in the first year, the experimental design was a completely randomized block design with three replications. treatments were, three drip irrigation ...
Surface irrigation is the dominant method of on-farm irrigation in Egypt as well as world wide. Furrow watering is considered as one of the main types of surface irrigation. Most of the cultivated crops are grown under such type of watering. The principal advantage of furrow irrigation is the less irrigated area comparing with that under basin irrigation which equaled total cultivated acreage. ...
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