Sugar Research and Development Corporation final report Increasing sugar cane yields by improvements in soil structure

Abstract

A project to increase sugar cane yields by improvements in soil structure was conducted at Broadwater, NSW. It was instigated in response to the poor physical structure of many cane soils and poor root development in many sugar cane crops resulting in low cane yields. A number of alternative management practices were tested and cane and sugar yield as well as appropriate soil parameters were measured. The main findings were that ridging had the biggest effects on cane and sugar yields and on soil bulk density, soil moisture (drier in the top 30 cm and wetter at depth), and a leaching of Cl, Na and S when in excess amounts. Ridging also resulted in a stable inter-row and hence far less damage during wet harvests. Intensity of tillage had some small effect on yields and soil structure; it is not clear if these would have increased over a longer period of time. The main effect of soybean production during the fallow period was due to nitrogen input. There were some small but positive effects on subsequent cane root growth soil organic carbon and soil bulk density. Mole drains and deep ripping provided no clear advantage over laser levelling alone.