Effects of long-term tillage practices on the quality of soil under winter wheat

These studies were done in 2013–2016 on the effects of two tillage systems on the quality of a loamy sand soil (Eutric Fluvisol) and were based on a field experiment started in 2002. Winter wheat was grown in conventional tillage (CT) with mouldboard ploughing (inversion) tillage; and reduced (non-inversion) tillage (RT) based on soil crushing-loosening equipment and a rigid-tine cultivator. Chopped wheat straw was used as mulch in both treatments. The physical, chemical and biological properties of the soil were investigated. RT increased soil bulk density in the 0–5 cm and 5–10 cm depth layers in comparison with CT. The greatest content of soil organic carbon (SOC) was found in the 0–5 cm layer under RT. The BIOLOG EcoPlate System showed that soil under RT had a greater metabolic activity and diversity of microbial communities than soil under CT. RT improved the quality of the surface soil as shown by the greater content of SOC and microbial activity measured in terms of dehydrogenases. However, the mean yields of winter wheat under RT and CT were similar. This suggests that the effects of increased bulk density (BD) on yield can be compensated by the effects of the improved microbial status.