Ammonia loss from sugar cane fields as affected by fertiliser placement, irrigation and canopy development

The new practice of trash retention following green cane harvesting has created new nitrogen fertiliser management problems for sugar cane growers in north Queensland. The trash cover retains soil moisture and prevents weed growth and soil erosion, so many growers do not disturb it but apply urea by broadcasting it on the surface. Few studies have been made of the fate of nitrogen applied in this way or of the efficiency of its use, and this information must be obtained before sound advice on fertiliser management can be provided to growers. This paper reports the results of experiments conducted by teams of scientists at three different locations to evaluate the effects of fertiliser placement, irrigation, and canopy development of ammonia loss from urea applied to green cane trash.