No-till farming systems in Australia

Australia has witnessed a remarkable transformation in land management over 50 years, as the technologies enabling no-till (NT) evolved and they were adapted by farmers to their own situations. The history of NT innovation reveals enduring principles regarding the value of collaboration between farmers and researchers and the need to develop NT as part of a farming system, to adapt to different climates and soils, and to be flexible enough to allow strategic tillage or residue burning for sound agronomic reasons. Soil structure improves under NT and there is often more water available, but individual crop yields overall are no better (except through more timely planting). Inefficient or incomplete water-use point to unrealised yield potential to be captured through improved management, particularly of subsoil constraints that often require tillage to ameliorate. The climate is not conducive to accumulating soil organic carbon, so increases with long-term NT have been small in Australia, especially under continuous cropping, which is becoming more common as sheep numbers fall and ley-farming declines. Diminishing contributions by pastures to the N economy of crops strengthens the demand for economically more competitive pulse varieties and weed management options, and for ongoing research to manage N-fertiliser more efficiently. Intensified cropping increases the major challenge of herbicide resistance. Herbicides are central to NT, raising questions about herbicide dependency and safety, and particularly about alternatives to glyphosate, which remains unrivalled for safety and cost-effectiveness. Maintaining registration is a key challenge. Current weed research emphasizes weed-seed management to reduce herbicide dependency. Accurate GPS and allied technology create opportunities for controlled traffic farming and ‘precision’ agriculture, offering prospects for further improving NT systems, including minimizing herbicide inputs.