Soil organic matter and environmental protection

Abstract

The importance of the soil organic matter (SOM) in the environmental protection, particularly its relation to the global carbon and nitrogen cycle come increasingly into the foreground. The evaluation of the influence of SOM on the environment requires the knowledge of optimal SOM content. Several authors estimated the necessary amount of primary organic matter (POM) for preservation of the optimal SOM content in soil on basis of the results from 10 long-term field experiments at eight different locations. An average demand for farmyard manure (FYM) was determined to be 10 t.ha^− 1.a^− 1. The difference in the organic carbon content between the unfertilized variant and the optimum fertilized variant ranged between 0.11% C_org on a sandy soil and 0.51% C_org on loess black soil. A higher level of organic fertilization brings no yield advantages and it is connected with higher N-losses. The utilization of FYM nitrogen is around 30% lower in comparison with mineral N. The reduction of the CO₂ concentration in the atmosphere by means of carbon sequestration in mineral soils is practically impossible. The input of primary organic matter to soil exceeds by large C quantity which can be accumulated.