Sugarcane postharvest residue management in a temperate climate

Authors: Viator, Ryan; Johnson, Richard; Boykin, Deborah; Richard Jr, Edward

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2009
Publication Date: 6/1/2009
Citation: Viator, R.P., Johnson, R.M., Boykin, D.L., Richard Jr, E.P. 2009. Sugarcane postharvest residue management in a temperate climate. Crop Science. 49(3):1023-1028.

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 if mechanical removal from the top of the row to the wheel furrow would produce yields equivalent to burning and to determine the optimal time in the sugarcane plant’s life cycle to conduct this removal. Mechanical removal resulted in lower yields (4%) than burning, but higher (5%) than where the residue was retained. The best time to conduct residue removal is before winter dormancy or during winter dormancy when the plant is not actively growing. Future research in Louisiana will focus on cultural practices including mechanical chopping of the residue to increase post-harvest residue decomposition to mitigate the adverse effects of retained residue on the row top and residue repositioned into the wheel furrow with mechanical removal.

Technical Abstract: Full retention of sugarcane (interspecific hybrids of Saccharum spp.) post-harvest residue often reduces subsequent ratoon crop yields in Louisiana. Experiments were conducted to determine the effects of different removal methods and removal timings on sugarcane growth and yield and to determine if residue management effects are consistent across ratoon crops of varying age grown on contrasting soil types. Removal methods consisted of partial mechanical removal, removal by burning, and full residue retention (control) applied to first, second and third ratoons grown on both heavy- and light-textured soils. For all ratoons, burning at pre-dormancy (6800 kg/ha) and complete dormancy (6610 kg/ha) and mechanical removal at pre-dormancy (6500 kg/ha) resulted in sugar yields greater than the control (6190 kg/ha). Burning in the spring, as the crop is beginning a new production year, actually decreased cane and sugar yields by 3.4 Mg/ha and 440 kg/ha relative to the control. Ratoons responded similarly to the residue management practices evaluated, and effects were consistent on both heavy- and light-textured soils. Residue decomposition from harvest until leaf emergence did not differ with ratoons and ranged from 30 to 35%. Future research in Louisiana will focus on cultural practices including mechanical chopping of the residue to increase post-harvest residue decomposition and development of sugarcane germplasm that emerges under cooler soil temperatures and has higher relative growth rates, attributes that may help mitigate the adverse effects of retained residue on the row top and residue repositioned into the wheel furrow.