abstractabout 30 to 50 percent of applied nitrogen fertilizers leached from soil to ground waters which can causes environment contamination and various human health problems. the rotation type can affect nitrogen mobility rate, so it is necessary to study effect of rotation type in on nitrogen movement. in order to evaluate effects of three main rotations in khuzestan province on inorganic for...

Subsidence of the Everglades Histosols occurs at a rate of approximately 3 cm/year. The major cause of this loss of soil is the oxidation of the organic matter by the microbial community. One of the products of this microbial activity is inorganic nitrogen. Assuming an annual subsidence rate of 3 cm, approximately 1400 kg/ha of nitrogen is released per year. Much of this nitrogen accumulates in...

Nitrogen is one of the major elements available to plants through biological nitrogen fixation, which has received much attention in recent years. The present study aims at improving tree legumes viz., Albizzia lebbeck, Pithecolobium dulce, Sesbania grandiflora, Albizzia amara, Enterolobium saman, Erythrina indica, Leucaena leucocephala, Acacia mellifera, Pongamia glabra and Acacia auriculiform...

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...

The study evaluated the response of alfalfa (Medicago sativa L) to arbuscular mycorrhizal fungi (AM) species Glomus intraradices and Sinorhizobium meliloti, strain 1021 regarding the dry biomass accumulation, mycorrhizal fungi colonization, nodulation and nitrogen fixation activity. Alfalfa plants were grown in a glasshouse until the flowering stage (58 days), in 4 kg plastic pots using leached...

Will nitrogen soil testing improve groundwater quality enough to decrease the demand for direct regulation? This question is addressed using a dynamic simulation model of irrigated agriculture in eastern Oregon. Results indicate that soil testing reduces applied nitrogen, increases farm profits and improves groundwater quality, but not enough to avoid regulation. Ronald A. Fleming is an Assista...

Field experiments were carried out in Huantai County from 2006 to 2008 to evaluate the effects of different nitrogen (N) fertilization and irrigation management practices on water leakage and nitrate leaching in the dominant wheat–maize rotation system in the North China Plain (NCP). Two N fertilization (NF1, the traditional one; NF2, fertilization based on soil testing) and two irrigation (IR1...

1.1 Biological nitrogen fixation and nitrogen nutrition in soybean plants Biological nitrogen fixation is one of the most important processes for ecosystem to access available N for all living organisms. Although N2 consists 78% of atmosphere, but the triple bond between two N atoms is very stable, and only a few group of prokaryotes can fix N2 to ammonia by the enzyme nitrogenase. Annual rate ...

global warming and climate change have drawn special attention to soil and its potential for stable carbon sequestration. soils are the largest stores of carbon in terrestrial carbon cycle and contain about three times more carbon than vegetation cover and two times more than that of atmosphere. studying the effects of grazing on soil carbon storage is important because of the major role soil o...