Long term investigations of the effect of tillage practices on crop production at Wagga Wagga, New South Wales

Abstract

Three seedbed preparation methods were compared from 1977 to 1989 to evaluate their effects on crop production. Treatments were conventional cultivation (CC, at least 3 workings pre-sowing), reduced cultivation (RC, 1 cultivation plus knockdown herbicide pre-sowing), and direct drilling (DD, no pre- sowing cultivation, knockdown herbicide only). Wheat (Triticum aestivum) was sown for the first 8 years of the experiment and lupins in 1985 and 1988. In 9 of the 11 years wheat grain yield was significantly better with DD, averaging 15% more than CC and 10% more than RC. Weed populations were generally greater where cultivation occurred; particularly fumitory (Fumaria spp.) and eyespot lodging (Tapesia yallundae) had greater impact on wheat in the CC and RC treatments.