Research conducted by the Yield Decline Joint Venture has shown that breaking the sugarcane monoculture using grain or green manure legume species, reducing compaction, and minimising the amount of fallow and in-crop tillage can individually increase the productivity of the subsequent sugarcane crop, improve soil health and rainfall capture and reduce production costs. This paper reports results of an experiment designed to evaluate the feasibility of integrating fallow legumes and reduced tillage with a crop row spacing that would minimise soil compaction into a new sugarcane farming system. Treatments had significant effects on various indices of soil health, soil N status, the rate of mineralisation of organic nitrogen reserves, and on the ability of soil to allow rainfall and irrigation water to infiltrate. The latter effect seemed to be associated with effects of treatments on the prevalence and activity of soil macrofauna (especially earthworms), and was the most important factor affecting the crop yield response. There were significant interactions between tillage and fallow management in cane yield, CCS and sugar yield, and there was a negative effect of fertiliser nitrogen on CCS. There were no significant differences in cane yield between bare fallows or soybean crops under conventional tillage, but cane yields were significantly higher after soybeans (either grain or green manure) under direct drill. Fallow management had no significant effects on CCS under direct drill, but both bare fallows and green manure soybeans produced significantly lower CCS under conventional tillage than direct drill. Collectively, there were no significant differences in sugar yields under conventional tillage, and tillage had no effect on sugar yields after a bare fallow. Sugar yields increased after direct drill soybeans, with highest yields after a green manure. Nitrogen fertiliser reduced sugar yields after a bare fallow, but had no significant effects after either soybean system. Results highlight the potential for combining legume fallows with minimum tillage or direct drill systems for the improvement of soil health, crop
productivity and water and nutrient use efficiency in future sugarcane farming systems.