In the tropics, cowpea is often intercropped with maize. Little is known about the effect of the intercropped maize on N2-fixation by cowpea or how intercropping affects nitrogen fertilizer use efficiency or soil N-uptake of both crops. Cowpea and maize were grown as a monocrop at row spacings of 40, 50, 60, 80, and 120 cm and intercropped at row spacing of 40, 50, and 60 cm. Plots were fertili...

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 ...

N2-fixing methanotrophs play an important role in the methane-nitrogen cycle in rice paddies. We report here the draft genome sequence of Methylosinus sp. strain 3S-1 isolated from rice root in a paddy field without N fertilizer input.

In order to discover the advantages and disadvantages of different fertilization regimes and identify the best management practice of fertilization in greenhouse fields, soil enzyme activities involved in carbon (C) transformations, soil chemical characteristics, and crop yields were monitored after long-term (20-year) fertilization regimes, including no fertilizer (CK), 300 kg N ha-1 and 600 k...

Grain legumes convert atmospheric N2 to reactive N through symbiosis with N2-fixing rhizobia. Biological N2 fixation associated with legumes and the subsequent decomposition of legume residues are the primary processes that replenish N removed by harvest in agroecosystems without the addition of fertilizer N (Galloway et al., 1995, Peoples et al., 1995). Therefore, legumes are often included in...

In order to study the effect of chemical and biological fertilizers on silage corn under different plant densities, a split plot experiment was carried out in a randomized completely block design with three replicates in south western Iran. The main plot included nitrogen fertilizer treatment at three levels (N1: with out chemical and organic fertilizers, N2: 75% chemical fertilizer + 100% orga...

Industrially produced N-fertilizer is essential to the production of cereals that supports current and projected human populations. We constructed a top-down global N budget for maize, rice, and wheat for a 50-year period (1961 to 2010). Cereals harvested a total of 1551 Tg of N, of which 48% was supplied through fertilizer-N and 4% came from net soil depletion. An estimated 48% (737 Tg) of cro...

The production of corn or soybeans for bio-based fuels and materials requires significant inputs of nitrogen (FN) and phosphorus fertilizer (FP) to increase grain yields. Approximately 50% of these nutrients are integrated into plant biomass. The remaining 50% is volatilized, leached into surface and groundwater, or transformed into gaseous species such as N2, NO, or N2O. Recent efforts to comp...

Sustainable agriculture demands reduced input of man-made nitrogen (N) fertilizer, yet N2 fixation limits the productivity of crops with heterotrophic diazotrophic bacterial symbionts. We investigated floating ferns from the genus Azolla that host phototrophic diazotrophic Nostoc azollae in leaf pockets and belong to the fastest growing plants. Experimental production reported here demonstrated...

in order to study the effect of chemical and biological fertilizers on silage corn under different plant densities, a split plot experiment was carried out in a randomized completely block design with three replicates in south western iran. the main plot included nitrogen fertilizer treatment at three levels (n1: with out chemical and organic fertilizers, n2: 75% chemical fertilizer + 100% orga...