Long-term effects of tillage systems on liming efficiency, soil chemical properties and wheat yield in Southern Brazil

Context Sustainable management of the soil is one of the pillars of conservation agriculture (CA). Aims The objective of this study was to evaluate the long-term effects of soil management systems (SMS) on liming efficiency, soil chemical properties and wheat yield. Methods This study was part of a long-term experiment established in 1986 in Passo Fundo, Rio Grande do Sul, Brazil, but using data from 2008 to 2015 to explore the effects of agricultural lime applied in 2008. The experiment was laid out in a split-plot design where the main plot (SMS) were arranged in randomised blocks and the cropping systems (sub-plot treatments) were randomised within the main plots. This study assessed the effects of the SMS; i.e. two CA systems [no-tillage (NT) and reduced tillage] and two conventional tillage (CT) systems (disk ploughing + disk harrowing annually, and mouldboard ploughing + disk harrowing annually). Key results The NT system was the most sustainable due to improvements in soil organic carbon concentration. After liming, CT systems were more effective than CA systems in decreasing Al3+ toxicity and increasing soil pH and Ca2+ and Mg2+ concentrations at deeper soil layers. The NT system had a considerable advantage over other SMS, due to a greater average wheat yield (18%). Conclusions The SMS evaluated in this study modified chemical properties when compared with the native forest area. The NT system was the least detrimental to soil organic carbon, an important indicator of soil quality. Implications The NT system provided greater average wheat yield (18%), and thus was the most viable SMS for subtropical spring wheat production.