abstract plant species differ in their ability to grow at low available p soils in other words, plant species differ in p use efficiency at low p supply. this ability can be investigated by comparing p uptake efficiency of plants and relative effective factors. a pot experiment was carried out in the growth chamber and sugar beet, maize and groundnut were grown in a low available p soil in a co...

to evaluate the effect of chemical and bio-fertilizer on nitrogen, phosphorus and potash concentration, biochemical traits and calyxes yield of roselle, an experiment was conducted in the split plot based on randomized coplete block design with three replications, at the research station in zabol university, during 2013 and 2014. the main plot consisted of three levels: phosphorus, nitrogen and...

to evaluate the yield and quality of barley (hordeum vulgare)–vetch (vicia desycarpa) intercropping, a series of experiments were conducted at the experimental field of the college of agriculture, university of tehran, in karaj (iran) from 2003 to 2005. the ex-periments were arranged in a randomized complete block with a split plot design and four replications. three levels (0, 45 and 90 kg n h...

in order to evaluate the effects of nitrogen levels and its split application on growth indices and their relationship with grain yield of rice (cv. khazar), a field experiment was conducted at rice research institute of iran with 11 treatments arranged in a randomized complete block design with 3 replications in 2008. nitrogen fertilizer levels (10, 20 and 30 kg.ha-1) were applied according to...

extinction coefficient (k) is an important index that shows the rate of light decrease in canopy. net biomass accumulation is linearly related to cummulative light interception. the slope of this relationship is termed radiation use efficiency. a split plot experiment within randomized complete block design with three replications was conducted in april 2001 in sugar beet research station in ka...

In intensive integrated crop-livestock farming systems, the surplus of N at the farm scale may be large and reflects on the N balance at the field scale. A study was conducted to assess the N fertilizer efficiency in four private farms in intensively cropped areas of NW Italy, and to monitor the effects of agricultural practices on the mineral N concentration of the soil solution, sampled every...

Since nitrogen (N) is the most essential nutrient for plants and a major limiting factor in plant productivity, doubling agricultural food production worldwide over the past four decades is associated with a 20-fold increase in N fertilizer use. As a consequence, use of N fertilizers in agriculture has already shown a number of detrimental environmental impacts. Therefore, the need to reduce N ...