Organic matter and its distribution in structural aggregates of leached chernozems under different land use systems

Abstract

In this paper, we studied the distribution of organic matter in structural elements of leached chernozems from the Central part of the Republic of Moldova. It was established that the arable leached chernozems used in conventional agriculture lost on average 2.29% organic matter from the arable 0-12 cm layer, in comparison with the fallow soil. The 12-20 cm soil layer lost on average 1.78% of organic matter. The implementation of environmental-friendly farming practices has favored partial restoration of the organic matter content in these soils. Thus, in the arable 0-12 cm layer the organic matter content increased by 0.08% and in the next 12-20 cm layer - by 0.27%. Loss of organic matter in soils led to degradation of soil structure. Thus, the 0-20 cm arable layer of leached chernozems has a less favorable structure for plant growth; in the structure of the soil predominate blocky aggregates. Cultivation of the mixture of herbaceous and leguminous grasses during the 2007-2015 years led to the partial restoration of the quality of the structure, especially in the 10-20 cm layer of the soil. Leached chernozem under the fallow has an excellent structure, characteristic for natural soils. According to our results, the organic matter is not evenly distributed in the structural aggregates of the investigated soils.