Soil water, salinity and nitrogen content are three major factors affecting crop production in arid and semi-arid areas. This study was performed in two years of 2009 and 2010 in a semi-arid area in order to investigate the effects of irrigation water quantity (as main plot), quality (saline water, as sub-plot), nitrogen fertilizer (as sub-sub plot) and their interactions on growth and yiel...

most regions of iran are confronted with inadequate supply and excessive demand of water in agriculture sector mainly resulting from a high difference between water providing cost and its price. coping with such a challenge needs to determine the water price based on the economic principles and its value in agricultural production. the aim of this study was to determine the economic value of th...

In complex task domains, such as games, students may exceed their teachers. Such tasks afford diverse means to tradeoff one type of performance for another, combining task elements in novel ways to yield method variations and strategy discoveries that, if mastered, might produce large or small leaps in performance. For the researcher interested in the development of extreme expertise in the wil...

Feed represents the largest cost input in intensive catfish Ictalurus punctatus production. Daily feed rations are generally related to stocking densities, up to a point a t which high feeding rates begin to affect water quality. There has been no prior research to analyze the economic interactions between feeding and stocking rates. Econometric techniques were used to estimate a Just-Pope catf...

Due to increasing water and growing demand for food a more efficient water use system is needed for agriculture. This is more evidence for rice production with a higher water use for economical production. A large cultivar×water regime interaction exists for grain yield in rice. Therefore, information is required to adopt new rice cultivars with high yield potential under water-saving condition...

A more efficient water use system is needed for agriculture. This is more evidence for rice production with a higher water use for economical production. A large cultivar×water regime interaction exists for grain yield in rice. Therefore, information is required to adopt new rice cultivars with high yield potential under water-saving conditions. The objectives of this study were to analyze the ...

Organic agricultural systems are often assumed to be more sustainable than conventional farming, yet there has been little work comparing surface water quality from organic and conventional production, especially under the same cropping sequence. Our objective was to compare nutrient and sediment losses, as well as sweet corn ( L. var. ) yield, from organic and conventional production with conv...

as water is the most restrictive factor in national agricultural production, it is necessary to take decreased water consumption and increased water us efficiency in crop production into consideration. nowadays, spring sugar beet production areas are concentrated in the region with water limitation and hence, the increase in spring production area contradicts the principle of water and soil con...