The effect of reduced soil tillage on maize ( Zea mays L.) grain yield in Eastern Crotia (Yugoslavia)

Abstract

The effect of reduced soil tillage on the yield of maize after winter wheat was studied on 2 different soil types (i) meadow chernozem non-calcareous soil (Osijek) and (ii) level pseudogley (Feričanci). On both soil types, the highest and the most stable maize grain yields were obtained with conventional tillage, i.e. immediate post-harvest shallow ploughing to 10–15-cm depth in July, autumn ploughing to 30–35-cm depth at the end of September, spring harrowing of the winter furrow in February or March and atplanting in April, discing, Rau-combination system and conventional planting (Treatment 1). In comparison with conventional tillage, immediate post-harvest ploughing to 30–35-cm depth in July (Treatment 6), and immediate post-harvest shallow ploughing to 10–15-cm depth without autumn ploughing (Treatment 4), both coupled with conventional tillage and spring planting as in Treatment 1, as well as direct drilling into a post-harvest shallow ploughed field without autumn ploughing (Treatment 5), resulted on average in slightly lower yields on meadow chernozem soil in 1979–1982 and on pseudogley in 1979–1981. On both soil types, slightly lower yields were obtained with autumn ploughing to 30–35-cm depth at the end of September (Treatment 3) and on pseudogley, with spring ploughing to 20–25-cm depth in February or March (Treatment 2). In both treatments, the post-harvest shallow ploughing was omitted; conventional seedbed preparation was the same as in Treatment 1. On meadow chernozem soil, spring ploughing (Treatment 2) resulted in a highly significant yield reduction (23%). Spring discing to 5–8 cm at seedbed preparation in April (Treatment 7), and the complete elimination of tillage, i.e. zero tillage (Treatment 8), proved to be totally unacceptable because of high reductions in maize grain yield on both soil types.