The effects of extended fertilizer use on the content of soil organic matter in light and heavy fractions of Chernozems.

摘要

The parameters Clf (content of organic carbon in the light fractions [densities of <1.8 and 1.8-2.0 g/cm3], as a percentage of soil mass) and Cil (content of organic carbon in the clay fraction, as a percentage of soil mass) were used to evaluate humus in the plough layer of 3 types of Chernozem (typical deep chernozem, leached chernozem and ordinary chernozem). Statistically significant correlations were found between Cil and characteristics of Chernozem subtypes, and between Clf and fertilizer use. Soil organic matter in the light fraction (density <1.8 g/cm3) of Chernozems contained relatively little nitrogen. It is concluded that Clf or the ratio Clf:Cil can be used to evaluate changes in soil organic matter of Chernozems resulting from extended fertilizer use.