Organic matter and soils

H.-R. Schulten and M. Schnitzer, Chemical model structures for soil organic matter and soils. Soil Sci. /62 115 (1997). 

This complexity is further demonstrated by considering a series of 31 transfer pathways that interconnect plants, animals, soil organic matter, and soil mineral pools (190). 

Matthews et al. (2000a) have developed a field-scale model of emissions based on the above approach. In addition to the processes discussed above, the field-scale model allows for added organic matter and soil organic matter separately, and for the effects of inorganic terminal electron acceptors. Figure 8.4 shows that the model was capable of predicting seasonal emissions at a particular site from model parameter values measured independent of the emission data. 

Trumbore, S. (2000). Age of soil organic matter and soil respiration Radiocarbon constraints on belowground C dynamics. Ecol.Appl. 10(2), 399-411. 

Flaig, W. (1968). Uptake of organic substances from soil organic matter by plants. In Study Week on Organic Matter and Soil Fertility, Wiley-Interscience, New York, pp. 723-776. 

Jandl, G., Schulten, H.-R., and Leinweber, P. (2002). Quantification of long-chain fatty acids in dissolved organic matter and soils. J. Plant Nutr. Soil Sci. 165,133-139. 

However, the main disadvantages of tillage are undoubtedly soil degradation, increased erosion, increased breakdown of organic matter, and soil compaction (Foshee et al., 1997). Tillage can also destroy or injure tree and vine roots at or below the cutting zone. 

Indicates the pore space available for water and roots influenced by soil composition (mineral content, mineral type, and organic matter) and soil texture Affects adsorption of the chemical Affects the surface area where adsorption can take place Influences partitioning and availability of chemicals Affects ability of a soil to transmit water or air Dictates the porosity of the soil Affects the form, reactivity, solubility, availability, and toxicity of some contaminants Affects the toxicity of some substances (mainly heavy metals) with binding or antagonistic mechanisms, for example, by alkaline-earth metals and aluminum Organic matter content, type, and % carbon Influences soil sorption properties for heavy metals and... 

Mineralization is usually defined as the production of ammonium from soil organic matter. This is sometimes called ammonification, which is a less confusing term. Mineralization usually causes only a small fractionation ( l%o) between soil organic matter and soil ammonium. In general, the 6 N of soil ammonium is usually within a few per mil of the composition of total organic nitrogen in the soil. 

Hassink, J., Matus, F. J., Chemi, C., and Dalenberg, J. W. (1997). Interactions between soil biota, soil organic matter, and soil structure. In Soil Ecology in Sustainable Agricultural. Sy.stems. (L. Brussard and R. Fer-rera-Cerrato, Eds.), pp. 15-35. CRC Press, Boca Raton, PL. 

Burning is, therefore, usually less harmful to soil organic matter and soil fertility in forested areas than one might expect, and may even at times be beneficial in an indirect way if good cropping practices that were prevented by litter are made possible. 

The performances of LRP developed and ANN would be improved through the modified calculation methods and inclusion of additional input variables such as organic matter and soil water at certain special suction in addition to particle size distribution and bulk density. 

In "Organic Matter and Soil Fertility. Pontificiae Academiae Scientiamm Scripta Varia, 32, 535-577. 

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