introduction between oil seeds, from the quality, quantity and nutrition index point of view, canola has the top level . because of the solubility of n fertilizers, the time of urea application, is very important and one of the main reasons of the reduction in n application efficiency is utilization of urea in an inappropriate time. by precisely foliar application of nitrogen, the efficiency of...

the effect of nitrogen (n) levels on n uptake by high weed densities at early growth stages of corn (zea mays l., cv. double cross 370) was investigated for two years (2008-2009) at the agricultural research station of shiraz university. the experiment was arranged in a split-plot arrangement in the randomized complete blocks design with three replications. two levels of weed control (weedy and...

The C(3) grass Poa trivialis and the C(4) grass Panicum maximum were grown in sand culture and received a complete nutrient solution with nitrogen supplied as 1.5 mol m(-3) NH(4)NO(3). (15)N tracer techniques were used to quantify the relative use of root uptake and mobilization in supplying nitrogen to growing leaves in intact plants which either continued to receive nitrogen or which received...

The response of tropical forests to climate change will depend on individual plant species' nutritional strategies, which have not been defined in the case of the nitrogen nutrition that is critical to sustaining plant growth and photosynthesis. We used isotope natural abundances to show that a group of tropical plant species with diverse growth strategies (trees and ferns, canopy, and subcanop...

the effects of an azotobacter chrococum isolate (strain ag11) and vermicompost and their combined effects on a rain-fed winter wheat (var. zagros) nutrient uptake and growth and soil water content were investigated with a farm trial.  the dry matter yield was determined in 5 occasions. gravimetric soil water content, soil microbial respiration and the number of azotobacter were determined at sa...

Nitrogen availability is often a limiting factor in plant growth and crop productivity, but the application of nitrogen fertilizers to counteract nitrogen deficiencies can have detrimental economic and environmental effects. Therefore, it is important to understand mechanisms of nitrogen uptake, transport, and utilization within the plant. The most common form in which nitrogen is assimilated b...

Nigella sativa L. has been recognized as one of the most important medicinal plants in many parts world for centuries. The purpose current study was to evaluate effects fertilization and plant density on nitrogen uptake, utilization efficiency, productivity N. under Mediterranean conditions. three-year experiment set up a split-plot design with three replications. There were 2 densities; 200 30...