Sugarcane Microclimate and Yield As Influenced By Residue Removal after Greencane Harvest.

Trash layer (harvest residue consisting of leaves and tops) left after greencane harvest could impact the subsequent ratooning of sugarcane (a complex hybrid of Saccharum spp.) in terms of microclimate and early season cane growth. However, limited data are available on the influence of trash layer and its removal on microclimate, weed and sugarcane growth in Florida. A field experiment was set up on sand soil in Clewiston, Florida after greencane harvest during Feb 2014 in a randomized complete block design with six replications. Treatments consisted of four trash removal levels (0, 33, 66, and 100% trash removal, respectively) based on total amount of trash in each plot. Similar treatments were employed after harvest of first ratoon crop in Nov 2014. Data were collected on soil temperature (T_soil at 5- and 15-cm depth), early season stalk count, weed count, and cane tonnage and sugar yield at harvest. Average T_soil increased with trash removal during both first and second ratoon crops at 5 and 15-cm depths, particularly early in the growing season. During 2014, T_soil difference between 100% and 0% trash removal treatments at 5-cm depth ranged from 2.4 – 4.0 ^oF from March to early June, after which no differences were observed. Soil moisture did not differ between treatments during both first and second ratoon crops. Both weed count and biomass were significantly greater in 100% compared to 0% trash removal treatment. Greater stalk count was observed in plots where all trash was removed compared to plots with no trash removal during both years of the study. However, no differences were found in millable stalk count and weight, brix, cane tonnage and sugar yield in the first ratoon crop at final harvest. Results indicated potential of trash removal in minimizing negative consequences associated with trash layer after greencane harvest.