Comparison of no-tillage and conventional tillage in the development of sustainable farming systems in the semi-arid tropics

The results of 5 short-term (4-8 years) experiments and farm demonstrations in which no-tillage technology was compared with conventional or reduced tillage in the semi-arid tropics of the Northern Territory and Far North Queensland, during the mid 1980s to mid 1990s, are reviewed. In the Douglas-Daly and Katherine districts of the Northern Territory, dryland crops of maize, sorghum, soybean and mungbean sown using no-tillage with adequate vegetative mulch on the soil surface have produced yields comparable with, or higher than (especially in drier years), those obtained under conventional tillage. The importance of a surface mulch in ameliorating soil temperature, moisture and fertility, and in reducing soil movement and loss in crop production in the semi-arid tropics was confirmed. Management of mulch (pasture, crop residues and weeds) will be crucial in the application of no-tillage technology to the development of mixed dryland crop and livestock enterprises in the semi-arid tropics.