in order to evaluation the effects of different soil fertility systems on chickpea seed quality, field experiments were carried out in sanandaj agriculture research station of iran in 2007 and 2008 growing seasons. experimental units were arranged in split-split plots based on randomized complete blocks with three replications. green manure levels considered main plots, base fertilizer compound...

In this paper we develop a model to estimate nitrogen loading to watersheds and receiving waters, and then apply the model to gain insight about sources, losses, and transport of nitrogen in groundwater moving through a coastal watershed. The model is developed from data of the Waquoit Bay Land Margin Ecosystems Research project (WBLMER), and from syntheses of published information. The WBLMER ...

To study the effect of nitrogen fertilizer sources and foliar spray of organic acids on rice crop, In this regard, this test was performed in 2010 and 2011 years at ElGemmeiza Agricultural Research Station, El-Gharbia Governorate located at lat. 30.47, long 31.00 and 14.80 m above the mean sea; the used design was split plot randomized complete block with 3replications. Main plots, two nitrogen...

introduction: broadcast fertilization method increases fertilizer losses while results in lower nutrient absorption by plant roots. fertigation is an effective method to increase water and fertilizer efficiency and to reduce the losses of nitrogen. moreover, it allows farmers to apply the nutrients in splits and few amounts in response to crop needs. in the present study, a field experiment was...

Nitrogen management continues to be diffi cult due to transformations of nitrogen fertilizers that are possible when applied to soil and the uncertainties of weather (Cabrera et al., 2008). Nitrogen (N) 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 l...

Introduction ield experience and research demonstrate that manure nutrients can be readily substituted for commercial fertilizer. Fertilizer needs depend on soil test levels. Substituting manure at a lower cost than commercial fertilizer can result in signifi cant savings if relatively uniform application and distribution can be maintained. The less nutrient-dense manure requires more hauling o...

to study the effects of different levels of water stress and nitrogen fertilizer on seed yield and yield components of two common bean genotypes (phaseolus vulgaris), an experiment in a split plot factorial based on crbd with four replications was conducted at the research farm of university of tehran (karaj-iran) in 2010. water stress treatments as the main factor included normal irrigation (6...