Irrigation water demand accounts for more than 95% of the total water use in the Kaidu-kongqi River Basin. Determination of the spatial and temporal trends in irrigation water demand is important for making sustainable and wise water management strategies in this highly water deficit region. In this study, the spatial and temporal trends in irrigation water demand as well as net crop irrigation...

the main goal of this study was to investigate the way of affecting of water in production of cucumber. from aspect of econometrics, mutual relationships of production function and expenses have been analyzed in which translog cost function has been used. this function has been estimated using the conditional input demand functions, the shefard theorem, chemical fertilizer, animal fertilizer, l...

The improvement of irrigation systems in the Nile Delta is one of the most important attempts in Egypt to implement more effective irrigation technology by improving the existing irrigation networks. Demand delivery system in the existing irrigation network is using of mechanical gates structures to automatically divert water from one portion of an agricultural field to another in the desired a...

Environmentally sound management of N in apple orchards requires that N supply meets demand. In 1997, newly planted apple trees (Malus domestica Borkh. var. Golden Delicious on M.9 rootstock) received daily applications of N for six weeks as Ca(15NO3)(2) through a drip irrigation system at a concentration of 112 mg l(-1) at 2-8, 5-11 or 8-14 weeks after planting. Irrigation water was applied ei...

Regional irrigation water-demand planning is utilized to establish appropriate cropping patterns and estimate irrigation water demand. Although optimization methods have been extensively adopted, uncertainties of meteorological conditions and the complexity of spatial contexts make developing explicit and structured decision making extremely difficult. Rather than generating a single optimal so...

To cope with droughts and water scarcity in semi-arid to sub-humid climates require the development of preparedness measures. For irrigated agriculture these include the identification of irrigation scheduling strategies that minimize the water demand with acceptable impacts on yields Those strategies may be produced by simulation and focus on different levels of water demand, from average to d...

[1] Agricultural water use accounts for around 70% of the total water that is withdrawn from surface water and groundwater. We use a new, gridded, global-scale water balance model to estimate interannual variability in global irrigation water demand arising from climate data sets and uncertainties arising from agricultural and climate data sets. We used contemporary maps of irrigation and crop ...

hargraves-samani method is one of the methods for calculating plant evapotranspiration that needs minimum meteorological data. in order to evaluate et-hs model in determining sugar beet crop water demand in isfahan, an experiment was conducted at research field of department of agriculture, khorasgan branch, islamic azad university, isfahan, iranin 2005. the study was based a randomized complet...

Irrigation underpins agricultural productivity. The purpose of irrigation is to match water supply to crop water demand. The effectiveness of irrigation depends on the quality of the timing and duration of watering events, also called irrigation scheduling. Most farmers use heuristic rules to determine irrigation events. This often leads to over-watering which results in lower crop yields and w...

Agricultural irrigation practices will likely be affected by climate change. In this paper, we use a statistical model relating observed water use by U.S. producers to the moisture deficit, and then use this statistical model to project climate changes impact on both the fraction of agricultural land irrigated and the irrigation rate (m³ ha⁻¹). Data on water withdrawals for US states (1985-2005...