Legume nitrogen fixation

Plants take up inorganic nitrogen, either as atmospheric Nj, through symbiotic nitrogen fixation in legumes such as pulses, some shrubs and trees. 

The answer to the absence of fast-acting nitrogen fertilisers, with arable crops and grassland, has been threefold first, to make much greater use of farmyard manure, and to make sure that it is properly stored and not allowed either to be washed down the drains or to volatilise into the air second, to make much greater use of the legume for its power of nitrogen fixation, particularly white and red clover... 

Minimization of agricultural losses from soil toxins Toxins from soils appear to be responsible for inhibition of nitrogen fixation, metabolism and nodulation in legumes. Removal of toxins could be achieved by proper adsorption techniques and also by growing companion plants that contribute organic matter to microoranisms which help to destroy or degrade toxic chemicals. 

A class of plants, called legumes, has bacteria which extract N2 directly, converting it to NH3. This nitrogen fixation process, catalyzed by an enzyme produced by the bacteria, is highly efficient at usual temperatures and pressures. 

The main disadvantages of intercropping are competition between crops possible damage of the other crop during the harvest of one crop component complication of mechanization and cultivation decrease of symbiotic nitrogen fixation in legumes caused by plant competition for resources (Soon et al. 2004). 

Weston LA, Putnam AR (1985) Inhibition of growth nodulation, and nitrogen fixation of legumes by quack grass. Crop Sci 25 561-565... 

Rhizobacteria, deleterious, 13 349 Rhizobitoxine, 13 300 Rhizobium-legume associations, in nitrogen fixation, 17 296-298 Rhizofiltration, 3 783-784 defined, 3 759t Rhizopus nigricans, 11 4, 9 Rhizosphere defined, 3 1 bit RHO A-alumina, 2 394-395 Rhodacarborane catalysts, 4 217-218 Rhodamine B... 

Downie, J.A. (2005) Legume haemoglobins symbiotic nitrogen fixation needs bloody nodules, Curr. Biol., 15, R196-R198. 

Evans, H. J., Russell, S. A., Hanus, F. j. and Ruiz-Argiieso, T. (1988) The importance of hydrogen recycling in nitrogen fixation by legumes. In R. J. Summerfield (ed.). World Crops Cool Season Food Legumes. Boston Kluwer Academic Publishei pp. 777-91. 

Figure 7.2 Typical annual nutrient balances for irrigated rice soils pre- and post-1960 calculated from probable inputs (left side of each graph) and outputs (right side) (data from Greenland, 1997). Inputs come from R = rainfall, F = floodwater and irrigation, S = sediments, N = nitrogen fixation and M = manures and fertilizers. Outputs are due to removals in Cg = rice grain, Cs = rice straw. Cl = legume crop, S = seepage and percolation and G = gaseous emission...

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