|Richard Jr, Edward|
Submitted to: International Society of Sugar Cane Technologists Proceedings
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/17/2004
Publication Date: 1/30/2005
Citation: Viator, R.P., Johnson, R.M., Richard Jr, E.P. 2005. Challenges of Post-Harvest Residue Retention Management in the Louisiana Sugarcane Industry. Proceedings of the International Society of Sugar Cane Technologists. 25:238-244. Interpretive Summary: Burning of plant material that remains in the field after harvest is a common practice in Louisiana sugarcane production. Environmental and public health concerns are threatening the continuation of this practice. Other options, besides burning, are needed for the sustainability of this industry, but simply leaving the material on the field decreases yields. Studies were implemented to determine what causes yield loss and to investigate potential management practices to prevent yield loss. An increase in soil moisture and a decrease in soil temperature in the late winter and early spring appear to be the reasons for the yield decline. All commercial varieties had reduced yields where the material was not removed. Yields were higher where the material was removed in late winter compared to early spring. Mechanical removal proved similar to burning in terms of yield. Practical problems with mechanical removal, such as spring cultivation and nutrient availability, need to be addressed before this practice is widely adopted by producers.
Technical Abstract: The growing season for sugarcane in Louisiana is the shortest in the world. When not removed the post-harvest residue blanket can decrease cane yield by 4.5 to 13.5 tonnes/ ha. Studies were implemented to identify the reasons for this yield loss and cultural practices to mitigate this loss. Moisture and temperature were monitored from February to March in a replicated study with burn, mechanical, and non-removal treatments. Louisiana's four leading cultivars were grown with and without residue to determine any differences in tolerance to the residue layer. Date and methods of residue removal were also investigated to determine optimal management practices. During the monitoring period soil temperatures ranged from 8.4 to 26.0°C (16.8 average) where the residue was not removed and from 7.6 to 27.3°C (17.5 average) where the residue was removed. Soil moisture ranged from 2 to 33.3 kPa (8.0 average) in the non-removed plots compared to 3.4 to 45 kPa (12.4 average) in the removed plots. Most varieties responded similarly to residue conditions with non-removal decreasing sugar yields by 0.7 tonnes/ha compared to a January removal. The effects of mechanical removal proved similar to burning in terms of yield. Sugar yield was decreased by 1.2 tonnes/ha if the residue was burned after January. Producers should remove residue, either by burning or by mechanical means in January to prevent a yield loss. When growers are unable to remove the residue in January, they should remove residue mechanically rather than by burning. Increased moisture and lower temperatures caused by the residue appears to be the reason for the yield loss in Louisiana where excess, rather than inadequate moisture, is a limiting factor for growth. Removal of the residue will be especially critical during cold and wet conditions, which will slow the reemergence of the ratoon crop as it starts an already short Louisiana growing season.