WHAT IS THE IMPACT OF GREEN CANE TRASH BLANKETS IN WET AND TROPICAL ENVIRONMENTS?

Ratoon trials in the wet tropics of north Queensland were used to assess the impact of green cane trash blankets (GCTB) on biomass accumulation, yield, CCS and suckering of sugarcane. Trials were established in the South Johnstone, Mourilyan, Herbert River and Tully cane growing areas during 1998–2001. Trials included treatments of GCTB and burnt trash blankets. There were trends for increased biomass accumulation associated with the burnt trash blanket treatment between 90 and 180 days after harvest (DAH) in 75% of harvests, and with a green trash blanket during the 180 to 270 DAH period, for 63% of harvests across three sites. Nitrogen loss from the trash blanket in the period 90–180 DAH and subsequent mineralisation from the soil pool may be a factor causing this later growth in GCTB. There were no significant treatment differences on final cane yield and CCS of sampled stalks. Suckers consistently appeared at least one month earlier and in greater numbers in cane grown with a trash blanket.