نتایج جستجو برای: low efficiency irrigation
تعداد نتایج: 1566921 فیلتر نتایج به سال:
The review analysis of twenty two irrigation efficiency (IE) studies carried out in the Ebro River Basin shows that IE is low (average IE)(avg)(= 53%) in surface-irrigated areas with high-permeable and shallow soils inadequate for this irrigation system, high (IE)(avg)(= 79%) in surface-irrigated areas with appropriate soils for this system, and very high (IE)(avg)(= 94%) in modern, automated a...
Water has become increasingly scarce in northwestern China due to climate change, economic growth and burgeoning population. Improving agriculture water use efficiency is of strategic significance in promoting socio-economic water productivity for arid and semi-arid inland river basins. Based on the household-level data collected in Zhangye City, which is located in the middle reaches of Heihe ...
It is necessary to research a cheap and simple fixed water distribution device according to the current situation of the technology of low-pressure pipe irrigation. This article proposed a fixed water distribution device with round table based on the analysis of the hydraulic characteristics of low-pressure pipe irrigation systems. The simulation of FLUENT and GAMBIT software conducted that the...
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...
abstract due to limited water resources in agriculture, application of each strategy to economize water use and increase area under cultivation is very important. one such strategy is deficit irrigation. for optimal planning of deficit irrigation, it is necessary to determine different sensitive stages of plant water shortages. in this study the effect of deficit irrigation on growth and yield ...
I ncreasing production efficiency is becoming a major theme for producers in order to maintain or increase their economic return in an increasingly competitive global market. In the case of irrigated agriculture, producers must also address increasing public concern about water conservation, water quality, and environmental protection. Two irrigation management issues require attention in order...
evaluating the performance of irrigation systems by providing the possibility of increasing irrigation efficiency in those systems is an important factor in the field of water resources management. in this study, the performance of three systems were evaluated, including linear move sprinkler irrigation systems in maize, sugar beet and alfalfa fields of magsal agro-industrial company which is l...
Evaluation of actual irrigation system perfonnance should rely on an accurate hydrologic water balance over the area considered. In a companion paper, water uses are categorized as consumptive or noncon sumptive, and beneficial or nonbeneficial. Real perfonnance is based on water uses over a specified period of time, rather than observation of a single irrigation event (with associate potentia...
Film hole irrigation is an advanced low-cost and high-efficiency irrigation method, which can improve water conservation and water use efficiency. Given its various advantages and potential applications, we conducted a laboratory study to investigate the effects of soil texture, bulk density, initial soil moisture, irrigation depth, opening ratio (ρ), film hole diameter (D), and spacing on cumu...
in ordet to investigate economic efficiency of five cultural systems in sugar beet crop, including high input, medium input low input , high and medium inputs without 3 times irrigation after emergence, an experiment was conducted over two years (2002-2003) in agricultural and natural resources research center of khorasan. these systems were analysed by marginal analysis and linear program...
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