COMPARISONS BETWEEN CONVENTIONAL AND ALTERNATIVE SUGARCANE FARMING SYSTEMS WHICH INCORPORATE PERMANENT BEDS, MINIMUM TILLAGE, CONTROLLED TRAFFIC AND LEGUME FALLOWS

摘要

LARGE scale experiments (plot size >0.3 ha) combining controlled traffic, minimum tillage and legume fallows have been established in several cane growing regions as part of the Sugar Yield Decline Joint Venture's (SYDJV) program to establish a more profitable, sustainable and environmentally responsible sugarcane farming system. The plant crop, in the first two of these experiments at Gordonvale and Ingham, was harvested in late July and early October 2003 (13-14 month crop), respectively. Therewas no significant difference in cane yield between conventional 1.5 m rows, direct planted 1.5 m rows, 1.5 m raised beds with a single cane row, 1.8 m raised beds with dual cane rows, and 2.3 m slightly mounded beds with 3 rows of cane. No nitrogen was used in the experiment, as all treatments followed a soybean fallow. Yields of about 100 t/ha were obtained at Gordonvale, which were comparable with those from the remainder of the farm where nitrogen rates of 150 kg/ha were used. The season was one of the driest on record. Nevertheless, the raised beds, which were mainly employed to limit the potentially adverse effects of water logging during the wet season, yielded as well as the conventional cropping system. The potential of these raised bedsto improve yields in wet years is yet to be tested. Economic analysis of the cost of production under the different systems clearly indicates that substantial cost savings can be achieved by incorporating raised beds, minimum tillage, controlled traffic, and legume fallows into the sugarcane farming system. In addition, substantial improvements in environmental outcomes are likely to result from adopting the new system.