Long-term impact of reduced intensity tillage systems, straw and green manure combinations on the sustainability of agroecosystems

Abstract

Soil tillage has long-term impacts on the agroecosystems. Understanding the structure and functions of the soil ecosystem, when applying soil tillage systems of different intensity or direct drilling is an essential condition for any future farming system. It is very important to ascertain not only the short-term but also the long-term effects of soil tillage on the ecosystem below and above the soil surface. Tillage intensity affects not only physical properties of the soil but also carbon stocks in it. Since 1999, a long-term field experiment has been done at the Experimental Station of Vytautas Magnus University (Institute of Agroecosystems and Soil Science) at 54º52′50 N latitude and 23º49′41 E longitude. The soil of the experiment site is Epieutric Endocalcaric Endogleyic Planosol (Endoclayic, Aric, Drainic, Humic, Episiltic) according to WRB (2014), texture at 0–20 cm depth is silty medium loam (33.7% sand, 50.3% silt, 16.0% clay), at 20–40 cm depth – silty light loam (35.4% sand, 51.1% silt, 13.5% clay). The aim of study set out to evaluate the impacts of long-term tillage of different intensities in combination with use of plant residues and green manure on the sustainability of agroecosystems. The results of the effects on agrochemical soil properties, it can be stated that regular spreading of straw and shallow loosening and direct drilling significantly increased only the pH of the soil. In the plots where straw stayed on the soil surface the longest, until pre-sowing tillage (SR, GMR, NT), the soil pH and total nitrogen content increased. In the plough less tillage and direct drilling treatments, the contents of available phosphorus and potassium were highly differentiated and larger amounts were concentrated in the upper layer. Long-term use of plant residues and green manure in combination with a complex application of reduced soil tillage and direct drilling has a positive [...]