Short-term effects of double-layer ploughing reduced tillage on soil structure and crop yield

Abstract

Soil tillage is widely acknowledged to affect soil characteristics and agricultural productivity. This research investigates the short-term effects of various tillage methods on soil physical properties and crop yields at a Central German field site with a dry climate (mean temperature 9.5°C; annual precipitation 470 mm). Three tillage approaches were evaluated: conventional plough tillage (25 cm depth), cultivator tillage (18 cm depth), and double-layer plough tillage (15 and 30 cm depth). We assessed soil physical properties through standard laboratory analyses, compression tests, soil pore structure via X-ray computed tomography (X-ray CT) and crop yields over 3 years. The results indicate that cultivator tillage approach increased soil bulk density relative to conventional tillage, especially in the second year, though this effect diminished over time. Double-layer plough tillage emerged as a viable short-term alternative to conventional tillage, achieving comparable soil bulk density. Saturated hydraulic conductivity values were generally higher for soils under conventional tillage or double-layer plough tillage than for cultivator tillage, highlighting their soil loosening effect. Classical soil analysis methods combined with X-ray computed tomography provided valuable insights into tillage induced changes to soil structure. Cultivator tillage resulted in a distinct pore structure with reduced macroporosity and pore connectivity. Despite notable soil property variations, crop yields remained consistent across the tillage methods. Overall, double-layer plough tillage presents a sustainable option, moderately improving soil physical properties while maintaining crop yields. This study highlights the need to assess the short-term effects of tillage on soils and contributes to the broader dialogue on optimizing tillage strategies for effective soil management and crop production.