Sugarcane sustainability and soil carbon sequestration

Authors: White, Paul

Submitted to: Sugar Bulletin
Publication Type: Trade Journal
Publication Acceptance Date: 10/30/2019
Publication Date: 12/1/2019
Citation: White Jr, P.M. 2019. Sugarcane sustainability and soil carbon sequestration. Sugar Bulletin. 98(3):25-28.

Interpretive Summary:

Technical Abstract: Long-term monoculture agriculture can reduce soil health and fertility. A survey conducted in over 30 Louisiana fields demonstrated that long-term cultivation reduced soil carbon (by 45%), available nitrogen (by 26%), and potash (by 32%), as well as other macro and micro nutrients when compared to adjacent areas not previously cultivated. Rebuilding the lost soil carbon is a priority for developing sustainable sugarcane production practices. Production practices that tend to increase soil carbon include adopting reduced tillage, increased cropping intensity, mulching crop residue, and planting cover crops during fallow periods. The benefits of reduced tillage include increased soil aggregation, which improves soil carbon sequestration, and increases the soil’s water holding capacity, infiltration rate, and aeration. Increased cropping intensity reduces fallowed areas in favor of crops that produce biomass and contribute carbon inputs, including crop residue and roots, into the soil. Crop residue represents the single biggest input of carbon into the soil system. Mulching or sweeping the residue is preferred to burning, which releases the organic carbon back into the atmosphere as carbon dioxide. Cover crops planted between sugarcane rotations, or co-cropped in newly planted beds, provide additional carbon inputs to soil, as well as the potential for biologically-fixed nitrogen and improved soil microbial diversity.