Soil carbon and nitrogen contents play an important role in sustaining soil physical and chemical quality and help to have healthy environments. The continues conversion of rangelands to arable lands has the potential to change carbon and nitrogen sequestration. In this study to evaluate the effects of land use change on soil organic carbon and nitrogen stock, forty samples collected from north...

in order to study the effects of nitrogen fertilizer on yield and growth of soybean (glycine max l.) an experiment as factorial in rcb design with three replications was conducted during 2006 and 2007 years at north khorasan. factors were cultivar (hobbit, l.w.k., and williams), and nitrogen fertilizer (0, 50, 100, and 150 kg n/ha from urea source). results indicated that cultivar and n fertili...

crop rotation affect on crop nitrogen uptake and nitrogen use efficiency (nue). crop rotations with high nue decrease energy use and increase level of sustainability in agro ecosystems. the objectives of this research were to determine the suitable double cropping system for enhancing nue and evaluate the effects of crop rotation, n fertilizer rate and return of crop residue on nue. this study ...

background and objectives: over the last two decades, a large number of researches have been conducted regarding the importance of nitrogen in sugar beet. this indicate that there were needs to investigate more on nitrogen management to achive higher production and quality because less nitrogen application result in reducing yield and high nitrogen application would increase production costs an...

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...

BACKGROUND: One of limitation factor in agricultural plants production in dry areas, supply requires water. Also nutrition crop management is a necessary strategy for achieve sustainable agriculture. OBJECTIVES: Current study was conducted to assessment the effects of different irrigation regimes and several amount of nitrogen fertilizer on seed nutrition...