Free-living diazotrophs are diverse and ubiquitous in soil, contributing the nitrogen pool in natural ecosystems. The isolation of nitrogen-fixing microorganisms has relied on semisolid nitrogen-free medium enrichment, followed by multiple subculturing steps. These procedures limit the diversity of recovered isolates. In the current study, we investigated three different isolation strategies fo...

this research was carried out at agricultural and natural resources research center, isfahan, islamic republic of iran (kabootar abad) for two years (2006-2007). the experiment was conducted as a split plot arranged in randomized block design with four replications. treatments were four levels of n fertilizer [110, (160 = soil and water research institute recommendation), 210 and 260 kg ha-1] a...

anzali wetland on the south west of caspian sea is a unique ecosystem was registered as ramsar site at 1975. anzali wetland was deteriorated due to numerous disorder and poor water quality. the riverin input were strongly affective in the process of eutrophication where the eastern and central region was more degraded. the first survey on the eutrophication process was conducted at 1969, since ...

the effect of different fertilizing systems and drought stress during grain development on grain minerals of barley (hordeum vulgare l.) was studied in field experiments on a clay-loamy soil during 2007 and 2008 growing seasons. the treatments consisted of three irrigation regimes (main plots) of: non-stressed (ns, normal irrigation continued until the end of plant physiological maturity), ...

The rapid and non-destructive monitoring of the canopy leaf nitrogen concentration (LNC) in crops is important for precise nitrogen (N) management. Nowadays, there is an urgent need to identify next-generation bio-physical variable retrieval algorithms that can be incorporated into an operational processing chain for hyperspectral satellite missions. We assessed six retrieval algorithms for est...