Effects of mineral and organic fertilizers on soil organic carbon fractions in agricultural chestnut soil

Abstract

Soil organic matter can be analyzed on the basis of the different fractions. Changes in the levels of organic matter, caused by land use, can be better understood by alterations in the different fractions. Therefore in order to discover tendency of soil fertility sustainability it is significant to research on stable and labile form fractions of soil organic carbon by advanced methodology and modern technique. Our research work aimedto evaluate the effect of mineral and organic fertilizers on the labile and stable organic carbon of the chestnut soil in Mongolia. The soils samples used in this study we collected from variants of mineral (N60P40K40), organic (biohumus 1t / hec.) Fertilizer and their combination of the Long-term fertilizers experiments of Plant and Agriculture Institute Changes in soil organic C by land use for agricultural purposes occurred mainly in the fraction of particulate organic matter (> 20 μm). The clay and silt fractions were quatified with a Mastersizer S after distruction organic substances and carbonates using H₂O₂ and HCI and the sand fraction was determined by wet sieving. According to our research, the stable form of organic carbon in chestnut soil is 39, 0-40,1% of the total fine particle size and 59, 9-61,0% of the active form fraction. On the other hand, variants with fertilizer tend to have increased stabile composition of soil organic carbon. It indicates that soil fertility protection and increased stability are possible in the country’s agricultural technology if use mineral and organic fertilizers.