Humans are modifying both the identities and numbers of species in ecosystems, but the impacts of such changes on ecosystem processes are controversial. Plant species diversity, functional diversity, and functional composition were experimentally varied in grassland plots. Each factor by itself had significant effects on many ecosystem processes, but functional composition and functional divers...

in order to study the effects of herbicide rates of metribuzin on nodulations and growth characteristics of chickpea, a series of experiments were carried out at research greenhouses of ferdowsi university of mashhad during 2009 in a randomized complete block design with four replications. studied factors were: different doses of metribuzin herbicide (10- 25- 50- 75- 100- 125 percent of recomme...

a randomized complete block design with three replications was performed in rice research institute of iran, rasht in 2008, to find the effect of supplement foliar application of nitrogen and potassium on ’daylam‘ hybrid rice grain yield, its components and grain protein percentage. foliar application of 20 kg nitrogen (5 percent n) and 15 kg potassium (3 percent k2o) in different pre-anthesis ...

objective: an experiment was performed in ardabil (2012) to investigate the effects of manure consumption in different amounts on reducing nitrogen fertilizer consumption in potato cv. agria. methods: this research was conducted in factorial design based on randomized completely blocks design in three replication  in which two manure factors in three levels (control, 30 and 60 tons/h) and nitro...

Objective: An experiment was performed in Ardabil (2012) to investigate the effects of manure consumption in different amounts on reducing nitrogen fertilizer consumption in potato cv. Agria. Methods: This research was conducted in factorial design based on randomized completely blocks design in three replication  in which two manure factors in three levels (control, 30 and 60 tons/h) and nitro...

application of sewage sludge as a cheap and waste material is increasing for supporting plant essential elements especially in the soils of arid and semiarid regions. in the present greenhouse research, the effect of ardabil municipal sewage sludge on n, p, k, pb, cr, ni and cd concentrations in soil and plant and also spring wheat yield and growth indices was studied as a randomized complete b...

abstract the amount of needed fertilizer in agricultural soils depends to the type of crop. absence of enough fertilizer may cause in tensions in plants and consequently result in decrease in amount of product. according to the agricultural literature, soils containing total nitrogen amounts (n %) between 0.1-0.15 percent are considered as soils containing normal amounts of nitrogen. the values...