Pools of soil organic carbon and total nitrogen in long-term experiment on gleyic Luvisols

Abstract

Soil fertility is highly dependent on soil organic matter accumulation. However, due to human activity the content of organic matter in soil can change rapidly. Nowadays the priority in agriculture is given to the soil tillage system what influence in reduction of organic matter decomposition. For that, research was aimed to estimate the influence of different fertilization on the properties of loamy Gleyic Luvisols. The longterm experiment was annually examined in the period from 2006 till 2008, physical and chemical properties and, especially, changes in pools of organic carbon and nitrogen were estimated under the organic, organic-mineral and mineral fertilization systems. As it was observed, that under the Norfolk crop rotation while growing winter wheat (Triticum aestivum L), mangel or sugar beet (Beta vulgaris L), barley (Hordeum vulgare L) with perennial grasses, perennial grasses (timothy-grass (Phleum pretense L) 80 perc. and red clover (Trifolium pretense L) 20 perc.) organic fertilisation (once per rotation 50 and 100 t ha-1 of manure applied) have mainly influenced the changes in soil physical properties. The soil density was significantly decreasing, thus the soil porosity and the content of water stable aggregates was increasing. However, the manure application along with combined application of mineral fertilizers (N31P38K75 and N79P65K90) in spring before planting or vegetation starts) have influenced the significant accumulation of organic carbon in Luvisols. On the other hand, humus in soil has significantly increased only in plots where organic fertilizers were applied. It is important to notice, that if to compare with control Luvisols in organic or mineral fertilization system have been significantly intensively accumulating nitrogenVytauto Didžiojo universitetasŽemės ūkio akademij