Long-term trials supporting N management guidelines for sugarcane grown in the Australian moist tropics

Long-term trials supporting N management guidelines for sugarcane grown in the Australian moist tropics

Heightened environmental awareness and the tightening of economic circumstances contributed to the increased attention to nitrogen (N) management in Australian sugarcane production during the past 25 years. The modification of N management guidelines was supported by a transformational process that included several key long-term rates of N trials. This paper describes one of these trials that was used for calibrating and validating the N management guidelines for variable climatic conditions in the Queensland moist tropics. Responses to the applied N did not occur in the plant crops, predominantly due to N from the preceding fallow legume crops. Variable yield responses to the applied N occurred in the ratoon crops. Optimum N rates (95% of the maximum attainable yield from fitted quadratic functions) also varied across the seasons. This confirmed that no constant relationship existed between the achieved yield and the amount of N applied. The variable rainfall in the moist tropics had a marked effect on the sugarcane yield. Relatively dry seasons resulted in good yields. Overly wet seasons resulted in poor yields. The SIX EASY STEPS® nutrient management program provides appropriate N rate guidelines, despite the variable rainfall conditions. Further refinement of the N requirement for each crop is not possible without a prior knowledge of the resulting yield responses.

Files associated with this item cannot be displayed due to copyright restrictions, but may be accessed online. Please see the link in the URL field.