Organic matter reactions

Y. Chen, Organic matter reactions involving micronutrients in soils and their effect on plants. Humic Substances in Terrestrial Ecosystems (A. Piccolo, ed.), Elsevier Sciences B. V., Amsterdam, 1996, p. 507. 

Stevenson F.J. Organic matter reactions involving pesticides in soil. In Bound and Conjugated Pesticide Residues, D.D. Kaufman, G.G. Still, G.D. Paulson, S.K. Bandal, eds. Washington American Chemical Society, 1976. 

Organic Sorbate-Natural Organic Matter Reactions... 

Stevenson, F.J. (1972). Organic matter reactions involving herbicides in soil. Journal of... 

Figure 3.6. Modes of interaction of natural organic matter with a clay mineral surface. The figure depicts cation (M) and water bridging, along with van der Waals interactions (through the sugar moiety). Reprinted with permission from Stevenson, F. J., and Ardakani, M. S. (1972). Organic matter reactions involving micronutrients in soils. In Micronutrients in Agriculture, Mortvedt, J. J., Giordano, P. M., and Lindsay, W. L., eds., Soil Science Society of America, Madison, WI, pp. 79-114.

Stevenson, F.J. and Ardakani, M.S., Organic matter reactions involving micronutrients in soils, in Micronutrients in Agriculture, Mortvedt, J. J., Ed., Soil Science Society of America, Madison, WI, 1972. 

FIGURE 11. Schematic diagram of organic matter reactions involving micronutrients in soil. From Stevenson and Ardakani (1972) as modified from Hodgson (1963). 

The reduction of nitrate via nitrite to ammonia occurs in soils at low rates (Rosswall, 1982). If it were possible to stimulate the reduction of nitrate to ammonia and then its incorporation into the organic matter (reaction 4), large nitrogen losses resulting from denitrification could be prevented so that a high fertility status could be maintained. 

Stevenson, F. J. (1976b). Organic matter reactions involving pesticides in soil. Am. Chem. Soc. Symp. Ser. 29, 180-207. 

In the Floridan aquifer, traces of gypsum are present in the carbonate rock. The high calcium concentration from gypsum dissolution exceeds its value at saturation with calcite, leading to precipitation of the carbonate and the production of additional CO2 (reaction 8). Concurrently, anaerobic decay of buried organic matter (reaction 3) and sulfate reduction (reaction 6) take place. The combination of these processes has caused an increase in the CO2 pressure of the groundwater from 10" bar in the recharge zone to 10" bar downdip as the pH decreases from 8.0 to 7.4 over a map distance of 115 km (Fig. 5.3) (cf. Back and Hanshaw 1970 Plummer et al. 1983). 

During the period of 1941 to 1955 Mattson and Koutler-Andersson were the most active contributors to our knowledge of ammonia-organic matter reactions. Their chief... 

The significance of the nitrite—soil organic matter reaction in connection with the loss of gaseous nitrogen in the forms of N2 and N O is considered in Chapter 13. 

Carter and Allison (1961) also observed losses of nitrogen ranging up to 37% when heavy applications of ammonium sulfate were added to acid soils limed to pH 6.6. The mechanism of loss was not determined but in the light of more recent investigations it is quite possible that a nitrite-organic matter reaction was responsible for the gaseous nitrogen loss. 

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