Production and environmental benefits of trickle irrigation for sugarcane: A review

It is widely recognised that trickle irrigation systems can lead to improved water and nutrient use efficiency, reduced off-site impacts, and increased crop growth. However, this is not always the case. The benefits arc only captured if a system is tailored to soil type and crop demand. This paper reviews the current information available in the national and international literature on the productivity of sugarcane under trickle irrigation systems, with particular attention water and nitrogen management. Early research showed few advantages of trickle irrigation. However, studies published since the mid-1980s have shown yield increases of 5%-20%, although these increases do not necessarily persist through ratooning. A small number of studies have found irrigation usc efficiency has increased by 50%-80% under trickle irrigation. Scheduling methods have not been fully investigated, so only a broad range of optimum crop factors (i.e., between 0.5 and 1) can currently be identified. Irrigation can also be managed to maintain soil at, or near field capacity for successful production. Unlike data on water management, there have been few published reports of nitrogen management via trickle irrigation of sugarcane. One of these studies suggests that nitrogen applications can be reduced under trickle irrigation, but studies on other crops, such as citrus, show that nitrogen leaching is substantially enhanced where too much water and/or nitrogen is applied. Modelling tools have recently become available that will allow results of individual trials to be extrapolated through time and across soil types. Application of these tools may form the basis for better understanding of the performance of trickle irrigation systems and future design and management guidelines.