in order to study of effects of integrated biological and chemical  fertilizers on  fertilizer use efficiency, grain yield and related traits to  grain growth of barley (hordeum vulgaris l.), a factorial experiment was conducted based on randomized complete block design with three replications in research farm of the faculty of agriculture sciences, university of mohaghegh ardabili in 2012. tre...

The most important problem in achieving high yields in rice is how to increase the nitrogen (N) absorption at each growth stage without reducing the percentage of ripened grains. Proper amount and timing of application could reduce N losses and increase fertilizer use efficiency while cost of production is also reduced and yield is increased. In order to avoid losses and to use soil-and fertili...

High N loss and low N use efficiency (NUE), caused by high N fertilizer inputs and inappropriate fertilization patterns, have become important issues in the rice (Oryza sativa L.) growing regions of southern China. Changing current farmer fertilizer practice (FFP, 225 kg ha-1 N as three applications, 40% as basal fertilizer, 30% as tillering fertilizer and 30% as jointing fertilizer) to one-tim...

Increased phosphorus (P) fertilizer use and livestock production has fundamentally altered the global P cycle. We calculated spatially explicit P balances for cropland soils at 0.5° resolution based on the principal agronomic P inputs and outputs associated with production of 123 crops globally for the year 2000. Although agronomic inputs of P fertilizer (14.2 Tg of P·y(-1)) and manure (9.6 Tg ...

Nitrogen fertilizer in the form of urea is subject to ammonia volatilization through the activity of the urease enzyme found ubiquitously in soil (Kissel et al., 2008). Nitrate fertilizer is subject to leaching (Randall et al., 2008) or denitrification (Coyne, 2008), depending on the water content of the soil and water movement through the soil. Ammonium forms of N can be fixed (Kissel et al., ...

Nitrogen fertilizer in the form of urea is subject to ammonia volatilization through the activity of the urease enzyme found ubiquitously in soil (Kissel et al., 2008). Nitrate fertilizer is subject to leaching (Randall et al., 2008) or denitrification (Coyne, 2008), depending on the water content of the soil and water movement through the soil. Ammonium forms of N can be fixed (Kissel et al., ...

high quantity of chemical fertilizer use in farms to increase production but low efficiency irrigation leaches part of nitrate and follows groundwater pollution. in this research, extra water below root zone as deep percolation collected with point drains which installed interface of natural drainage zone and agricultural soil in university of tehran research farms. then, concentration of nitra...