2011 Annual Report
1a.Objectives (from AD-416)
The first objective of the research is to develop new crop and soil management techniques for sugarcane production that overcome limitations in soil and nutrient resources and maximize production efficiency. These techniques will incorporate elements of precision agriculture and remote sensing. The second objective of the research is to identify methods to mitigate the current yield loss associated with post-harvest residue retention and ripener usage in sugarcane production.
1b.Approach (from AD-416)
To address the first objective, a series of experiments will be initiated to investigate the response of sugar and energy-canes to variations in macro- and micronutrients. Results from these experiments will be used to identify critical fertility components and to optimize fertility rates for both sucrose and biomass production. Initial macro-nutrient experiments will focus on nitrogen (N), a critical component of a sugarcane fertility program whose cost has risen dramatically. Initial micronutrient experiments will focus on nickel (Ni) a nutrient that is associated with increases in disease resistance and copper (Cu) which is associated with increases in both cane and sugar yields and may also influence disease resistance. In addition, experiments will be conducted on commercial farms to investigate the utility of electrical conductivity (EC) and soil pH mapping, zone sampling, and variable-rate (VR) application techniques to optimize nutrient availability. All treatments will be arranged in randomized complete block design (RCBD) with six replications. Finally, we will investigate the utility of a newly designed yield monitor and leaf reflectance measurements, from multi-band aerial imagery and from direct hyperspectral measurement as potential indicators of cane biomass levels and sucrose content and to identify crop stresses associated with improper fertility levels of sugarcane dedicated for either sugar or bioenergy. To address the second objective, studies will be initiated to investigate the carry over response of sugar- and energy-cane crops to post-harvest residue and ripener applications made in the previous crop year. The response of energy-canes and newly-released sugarcane varieties to these factors has not been tested. In addition, studies will be implemented to screen basic and commercial germplasm for tolerance to post-harvest residue retention and to screen for self-defoliating clones that may expedite the natural decomposition of leafy residue prior to harvest. Finally, a study will be initiated to investigate in crop N application rate effects under various post harvest residue management schemes to include: partial removal, complete removal by burning, and no removal.
Preliminary results suggest that Louisiana sugarcane growers could save money by reducing nitrogen (N) rates in both plant and stubble crops, while maintaining crop yields.
Preliminary results with both nickel (Ni) and copper (Cu) suggested positive yield effects in both plant-cane and first-ratoon trials. Yield monitor data was collected on commercial sugarcane farms in the fall of 2010 and results indicated that the system was effective at predicting and mapping cane yields.
First-ratoon data indicate that the stresses of glyphosate carryover and full residue retention appear to compound each other as indicated by reductions in cane and sucrose yields. The first-ratoon residue management for energy cane experiment was harvested, and the first year of data indicates that residue management strategies will vary depending on if cane is grown for sugar or biofuels. Residue treatments were applied to basic and commercial germplasm screening studies to identify clones tolerant to the cool, wet conditions caused by the retention of post-harvest residues. In another test that evaluated self-defoliating varieties as an alternative to burning, preliminary data indicates that residue decomposition is not enhanced with early defoliation. Preliminary data using new cultural practices as an alternative to burning indicate that additional nitrogen applied with mechanical removal of residue, produced yields equivalent to where the residue was removed by burning.
Cultivation affects sustainability of cane yields. In Louisiana, sugarcane farmers typically cultivate cane three to six times during each production year of a four-year crop cycle. Eliminating cultivation passes during one or more years of a crop cycle may reduce production expenses without impacting yield. ARS scientists at Houma, LA, demonstrated that conventional cultivation increased sugar yields by 700 and 600 kilograms/hectare during both the plant-cane and first-ratoon production years. Cultivation did not affect yields of the second-ratoon crop, while in the third-ratoon crop no cultivation increased sugar yields by 700 to 1,000 kilograms/hectare only if the crop had been cultivated in either plant-cane or second-ratoon. Results suggest that cultivation is beneficial especially in the early years of the crop cycle, but that cultivation can be eliminated during the third-ratoon crop year thus reducing grower input costs.
Soybeans can improve sugarcane grower profitability. Sugarcane growers in Louisiana use the March to July fallow period every fifth year between sugarcane cycles to restore drainage and destroy weeds that cannot be easily controlled within the crop with herbicides. One method of controlling these weeds is the use of two to three applications of glyphosate beginning in late April. This is a costly process as no revenue is returned to the grower until the harvest of the plant-cane crop the following year. Research has demonstrated that soybean intercropped in the traditional sugarcane fallow period between sugarcane crops can generate $80/acre of additional net farm revenue. More importantly, soybean intercropping did not negatively affect subsequent plant-cane yields of sugarcane. Soybean intercropping on 125,000 acres of fallow ground in 2010 would generate $10 million in additional net farm revenue.
Billet planting of sugarcane economical in Louisiana. In recent years, producers began to experiment with using the chopper harvester - which cuts the stalks of seed cane into 58-60cm pieces (billets) - as an alternative to the planting of whole stalks cut with a whole-stalk harvester. With billet planting, more seed cane is required to insure adequate plant cane stands and still lower yields are often experienced compared to whole-stalk planting. ARS scientists at Houma, LA, initiated a study with the variety LCP 85-384 at the USDA, ARS Ardoyne Research Farm near Schriever, LA, to determine the effects of billet planting rate (hectares planted per hectare of seed cane harvested) and billet position within the furrow on cane and sugar yields. When a comparison was made between cane and sugar yields from the 3:1 planting ratio (industry standard for billets) and a 5:1 ratio (less seed used), no significant differences were noted. These results indicate that billet planting with LCP 85-384 can be made economical by reducing planting rate without negatively influencing cane or sugar yields.
Price, R.R., Johnson, R.M., Viator, R.P., Larsen, J., Peters, A. 2011. Fiber optic yield monitor for a sugarcane chopper harvester. Transactions of the ASABE. 54(1):31-39.
Viator, R.P., White Jr, P.M., Richard Jr, E.P. 2011. Sustainable production of energycane for bio-energy in the Southeastern U.S. American Chemical Society Book Series, Sustainability of Sugarcane for Sugar and Bioenergy. 1058:147-161.
Viator, R.P., Johnson, R.M., Richard Jr, E.P. 2010. Effects of cultivation frequency on sugarcane yields. Sugar Cane International. 28(6):259-265.
Johnson, R.M., Richard Jr, E.P. 2011. Prediction of sugarcane sucrose content with high resolution, hyperspectral leaf reflectance measurements. International Sugar Journal. 113:48-55.
Viator, R.P., Dalley, C.D., Richard Jr, E.P. 2011. Late-season glyphosate ripener application coupled with post-harvest residue retention impacts subsequent ratoon yields. International Sugar Journal. 113(1349):374-380.