Michael E. Salassi, Michael A. Deliberto, Kenneth A. Gravois and Benjamin L. Legendre

Sugarcane is one of the major agricultural commodities produced in Louisiana. With more than 400,000 acres of sugarcane in production and 11 factories processing approximately 14 million tons of sugarcane into 1.5 million tons of raw sugar and more than 95 million gallons of molasses annually, sugarcane is one of the major economic drivers of the state’s agricultural sector. With raw sugar and molasses as the primary products produced, the annual value of the state’s sugarcane crop has averaged $948 million per year over the 2011-2013 crop years. This annual revenue from sugarcane production has an estimated impact of approximately $2 billion per year on the state’s economy. Louisiana is also one of the major sugarcane-producing states in the United States, accounting for approximately 48 percent of total sugarcane acres and 43 percent of total cane sugar produced in the country.

Sugarcane’s production process is much different from that of other Louisiana agricultural crops. Sugarcane is planted vegetatively using whole stalks of sugarcane rather than seed as is typical for other crops. It is a perennial crop, whereby several years of harvest can be obtained from one initial planting. In addition, the practice of prescribed burning is an integral part of the sugarcane production process. Prescribed burning is a crop management practice widely used in the production and harvest of many agricultural and timber products across the United States. In Louisiana, prescribed burning is widely used in sugarcane production to reduce the amount of excess plant material associated with the harvest, transportation and processing of sugarcane into raw sugar and molasses. The annual economic value of prescribed burning to the Louisiana sugarcane industry is estimated to be approximately $120 million per year.

Benefits of prescribed sugarcane burning

The primary purpose of burning sugarcane, either before or just after harvest, is to remove unwanted plant material from the field, primarily plant leaves and tops. If left on the field, this plant material can reduce succeeding crop yields. If transported to the mill with harvested sugarcane, this plant material can increase processing costs and reduce raw sugar recovery. The burning of sugarcane as a crop harvest management practice has many direct and indirect benefits. Some of the major direct benefits of sugarcane burning in Louisiana include: (1) reducing the number of truckloads needed to transport harvested sugarcane to the mills, thereby reducing traffic and wear and tear on public roads; (2) decreasing the volume of plant material processed at raw sugar mills, thereby shortening the harvest and processing season; (3) increasing raw sugar recovery from processed sugarcane, thereby improving the overall quality of the sugar; and (4) decreasing crop yield losses in subsequent sugarcane stubble crops, thereby extending the crop cycle and reducing planting costs.

Prescribed burning of sugarcane also has several indirect benefits. Under certain crop conditions, burning the sugarcane crop before harvest can improve the efficiency of harvesting the crop in the field, thereby reducing the cost of harvesting sugarcane. In addition, burning the sugarcane field can reduce plant diseases that might overwinter on remaining crop material, reduce insect pest populations within fields on subsequent stubble crops, and reduce the establishment and spread of weeds.

Economic value of prescribed sugarcane burning

Four direct components of the annual economic benefit of sugarcane burning were estimated using 2011-2013 crop year average sugarcane production data. These average base data values, used in the determination of the economic value of sugarcane burning, included measures of acres of sugarcane in production, acres of sugarcane harvested for sugar, tons of sugarcane harvested, average raw sugar recovery rate, and average raw sugar and molasses market prices.

Reduction in additional transportation costs
Without burning, the addition of lighter plant trash material in trucks hauling harvested sugarcane to the mills would reduce the hauling weight from the typical 27 tons of sugarcane per truckload to about 25 tons per load. This would require an estimated 94,546 additional truckloads to haul the state’s annual sugarcane crop to mills. Using a representative hauling cost rate of $6 per ton, the estimated value of this additional transportation cost would be $14.2 million per year.

Reduction in additional processing costs
Additional plant trash material shipped to the mill along with harvested sugarcane as a result of not burning would result in the processing of an additional 1.35 million tons of plant material at the state’s raw sugar mills. Using a typical in-season variable grinding cost per ton for an average-sized mill in the state, the estimated value of this additional processing cost would be $6.1 million per year.

Reduction in sugar recovery losses
Additional plant trash material processed would reduce sugar recovery by about 3 pounds per ton of cane for every additional 1 percent trash. Without burning, the additional plant material processed at mills would be approximately 9.1 percent, thereby reducing sugar recovery by 27 pounds per ton of cane processed. Using the previous three-year average prices for raw sugar and molasses and factoring in typical price discounts for impacted sugar quality, the estimated value of revenue loss from reduction in sugar recovery would be $29.8 million per year.

Reduction in stubble crop cane yield losses
Additional plant trash material left on the fields without burning would reduce sugarcane yields on the succeeding stubble crops. Using an approximate yield reduction factor of 11 percent based on previous research, the estimated value of this sugarcane yield reduction on stubble crop acreage would be $70.2 million per year.

Combining these four values together provides a direct estimate of the annual value of the economic benefit of burning to the Louisiana sugarcane industry of approximately $120.3 million per year. Prescribed burning is vital to the continued economic viability of the Louisiana sugarcane industry. Programs like the Certified Burn Manager Program, which provide training to sugarcane farmers to understand and follow safe fire and smoke management guidelines, will help ensure that this important practice can continue.

Michael E. Salassi is the Nelson Fairbanks Endowed Professor in the Department of Agricultural Economics and Agribusiness, and Michael A. Deliberto is a research associate in the department. Kenneth A. Gravois is the extension sugar specialist at the Sugar Research Station in St. Gabriel. Benjamin L. Legendre is a professor and head at the Audubon Sugar Institute.

(This article was published in the Winter 2015 issue of Louisiana Agriculture.)