Impact of Sustainable Tillage and Sowing Machinery on Soil Physical Properties, Winter Wheat Crop Development and Productivity in On-Farm Scale Experiments

Abstract

Short-term on-farm scale field experiments were carried out in 2011-2012 in three different regions of Lithuania: Vilkaviskis (Central part of Lithuania), Pakruojis (Northern part) and Klaipeda (Western part). The soil of Vilkaviskis region was light silty loam, in Pakruojis region – sandy light loam and in Klaipeda region – sandy heavy loam. The aim of investigations was to establish the influence of sustainable soil tillage and continuous sowing on soil physical properties, winter wheat crop development and productivity in different regions of Lithuania. Soil was tilled with combination of Agrisem subsoiler (Cultiplow 52, up to 40 cm depth) and disc harrow (Combimulch, up to 5-8 cm depth). Winter wheat was sowed with Agrisem drill DISC-O-SEM-DS610-SUPER in continuous (scattered) manner. Results of investigations showed that applying of the subsoiling + disking (twice) combination warranted favourable soil physical properties for winter wheat development in different conditions of microclimate and soil texture. After winter wheat sowing and after wintering capacity of water stable soil aggregates was higher than 50%, soil bulk density and penetration resistance mostly did not reach limitary conditions (1.4 g cm-3 and 2.0 MPa). At the renewal of winter wheat vegetation in all experimental sites penetration resistance of top layers (up to 20-25 cm depth) was higher than after sowing. However, in spring in deeper soil layers soil penetration resistance decreased. That depended on higher soil moisture content and subsoiling impact. Despite of high coverage (61-74%) of soil surface by the oilseed rape residues, continuous sowing machine formed sufficient winter wheat crop density and leaded rapid crop development and plenty (up to 9.05 t ha-1) yield of grain