Impact of Sugarcane Mulch Management Strategies on Soil Erosion and Crop Yield

Since 1995, the sugarcane industry in Louisiana has been using a new harvesting system which involves the use of a combine harvester that cuts the cane stalks into billets, which are directly loaded into wagons for transport to the mill. Extractor fans deposit the plant residue on the soil surface. Historically, this sugarcane residue has been removed by burning. In recent years this burning of the residue has become objectionable to the general public because of health issues related to inhalation of the smoke. Because of these concerns, there is a need to find economical alternatives for residue management to identify benefits from residue with respect to reducing soil erosion and improving surface water quality. The primary purpose of this project was to evaluate the effect of postharvest residue (mulch cover) on the field with respect to crop yield and surface water quality. This project evaluated three management strategies with primary focus on mulch residue and its effect on soil erosion, surface water quality, and crop yields. The treatments include (1) burning the mulch after harvest and cultivating in the spring; (2) sweeping the mulch off of the top of the row after harvest and cultivating in the spring; and (3) leaving the mulch on the field after harvest and cultivating in the spring. Sugarcane plant population, yields, and quality of surface runoff water were measured for each treatment. Data were collected for 4 years and the burned treatment increased biomass yields by 7.8% and sugar yields by 9.8%. There was 11,865 kg/ha soil erosion from the plots during the first year. The soil erosion for the second year was 64% smaller. Over the 4 years, there were no significant differences among the soil, nitrogen, phosphorus, and potassium losses.