Spatial variability in crop production occurs as a result of spatial and temporal variations in soil structure and fertility; soil physical, chemical and hydraulic properties; irrigation applications; pests and diseases; and plant genetics. It is argued that this variability can be managed and the efficiency of irrigation water use increased by spatially variable application of irrigation water...

An agricultural water conservation policy prevalent worldwide encourages producers to improve on-farm irrigation efficiency. Contrary to intention, increasing empirical evidence reveals that this policy may set an ‘irrigation efficiency trap’ that worsens water crises by reducing water supplies and jeopardizing economic growth. We derive a pair of testable hydrologic-economic conditions require...

Irrigation consumes considerable water to satisfy the current food demand. An improvement in water use efficiency for irrigation is essential. Wind drift and evaporation losses reduce the water use efficiency of center pivot irrigation systems in arid and semi-arid areas. In this paper, a model of water vapor dynamics during and after overhead sprinkler irrigation was developed and validated by...

unsustainable harvesting of agricultural water resources in the province of kerman, has caused an annual average of one-meter drop in ground water levels. surface irrigation methods in pistachio trees have low efficiency because of inherent characteristics and its incorrect application, as well as low access to water resource in pistachio regions. therefore under the current critical condition,...

This research was conducted in 2007 and 2008 cropping seasons in the experimental field of Shahid Salemi, Ahvaz, south west of Iran. In each year, the study consisted of a split split-plot experiment, using Randomized Complete Block Design (RCBD) with three replications. Four irrigation levels including irrigationoff at the 8 leaf, the 12 leaf and the tasseling stages and optimum irrigation wer...

This paper develops the system of optimal allocation of water resources in irrigation district and irrigation decision support which integrates technologies of decision support, information management, information search and so on. It has the multi-function of water production function calculation, crop water requirement calculation, water resources optimal allocation and realtime amending the ...

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...