نتایج جستجو برای: irrigation losses cause rising water table during the season
تعداد نتایج: 16438912 فیلتر نتایج به سال:
daho has approximately 4 million acres of irrigated agricultural land. Most of it is in pasture and hay crops, grain crops, potatoes, and sugar beets, in hierarchical order. Table 1 shows the number of irrigated acres in the state by crop for 1994. Nearly all of this land is irrigated by either sprinklers (59 percent) or surface irrigation systems (40 percent), with only a very small amount (le...
The conservation of water is crucial to sustainable agricultural production in areas of low rainfall or uneven precipitation distribution. Under such circumstances, drip irrigation methods offer a useful option for economic production of vegetable crops. This preliminary study examined the efficacy and performance of two drip irrigation methods on cucumber and tomato crops grown out of season. ...
Rice is one of the high water consuming crops and it is important to utilize methods in its production to promote water use efficiency. In order to achieve this purpose, a split plot experiment was conducted in direct-seeding of rice in Kazerun region of Fars province, Iran, in 2007. Five irrigation treatments (full-season flooding, full-season alternating, flooding until tillering stage, flood...
Water shortage is a major constraint to sustaining and increasing the productivity of rice-wheat systems. Saving water can be elusive in that reducing seepage, percolation and runoff losses from fields does not necessarily save water if it can be recaptured at some other temporal or spatial scale, for example by groundwater pumping. Many technologies appear to save substantial amounts of water ...
Groundwater seepage contributes to irrigation return flows and surface waters. Knowledge of phosphorus (P) concentrations and loads in percolation water that enters the vadose zone and groundwater is necessary to assess and manage water quality. We measured the P in water leached below the crop root zone in a furrow-irrigated Pormeuf silt loam. Vacuum operated percolation samplers were used to ...
Using water and fertilizer management at the farm level can be increased water use efficiency and reduce the volume of drainage water, fertilizer losses, and other pollutants in farmland with deep underground drains such as Khuzestan agro-industrial Companies. In the present study, a comprehensive simulation model for the water cycle and the nitrogen dynamics modeling was used for water and fer...
The main objective of this study was evaluation of integrated management and mixing saline/fresh water on soil salinity distribution. For this purpose, a field was selected and 32 plots were made in it with a 6 m×2.5 m size. A split plot experiment was employed with two sunflower varieties (Alstar and Hisan33), four irrigation schemes (CIS) and four replications. Irrigation schemes being ...
a phase-locked loop (pll) based frequency synthesizer is an important circuit that is used in many applications, especially in communication systems such as ethernet receivers, disk drive read/write channels, digital mobile receivers, high-speed memory interfaces, system clock recovery and wireless communication system. other than requiring good signal purity such as low phase noise and low spu...
126 abstract: in this research we studied the effects of cyclic hydration and dehydration of cysts of artemia urmiana and artemia parthenogenetica on the hatching percentage, survival and growth. the experiment was carried out in 3 treatments (1-3 hydration/dehydration cycles) with 3 replicates for each treatment. later effects of cold preservation at -20°c during three time periods were ...
2 The aim of this study was to establish threshold TGR and MDS values which could be 3 used in regulated deficit irrigation in future work. Three irrigation treatments were 4 performed during three seasons in a 37 year-old table olive orchard in Seville (Spain). 5 Control treatment was irrigated with 125% of the crop evapotranspiration. Regulated 6 deficit irrigation (RDI) treatments were perfo...
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