Effects of cultivation frequency on sugarcane yields

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

Submitted to: Sugar Cane International
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/30/2010
Publication Date: 11/1/2010
Citation: 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.

Interpretive Summary: 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. Treatments consisted of either no or conventional cultivation. Conventional cultivation consisted of two cultivations of the sides of the rows before fertilization in April, cultivation immediately after fertilization, and a final cultivation (layby) in mid-May. Conventional cultivation increased sugar yields by 700 and 600 kg ha-1 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 1000 kg ha-1 only if the crop had been previously conventionally tilled in either plant-cane or second-ratoon. With the use of herbicides there is no need to mechanically control weeds. However, there are other benefits to cultivation as indicated in our study. Our 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.

Technical Abstract: Reducing the number of cultivations during one or more years of a four year crop cycle may potentially reduce production expenses for Louisiana sugarcane growers. This study was initiated to determine the effects of cultivation on yields of sugarcane grown on a clay soil both on an annual basis and throughout a cane-cropping cycle, which in Louisiana consist of plant-cane through third-ratoon. Whole-plot treatments in plant-cane were either no or conventional cultivation. Conventional cultivation consisted of a total of four cultivations with two inter-row cultivations before fertilization, one cultivation immediately after fertilization, and a lay-by cultivation. For the no cultivation treatment, rows were left undisturbed except for knifing fertilizer on both sides of the planted line of sugarcane in April each year of the crop cycle. For every subsequent ratoon crop, the whole plots established in the previous crop were split with split-plot treatments being no or conventional cultivation. Thus, split, split-split, and split-split-split treatments were initiated in the first-, second-, and third-ratoons, respectively. Conventional cultivation increased sucrose yields by 700 and 600 kg ha-1 in the plant-cane and first-ratoon crops. Cultivation treatments resulted in equivalent yields in the second-ratoon crops. In the third-ratoon, the no cultivation treatment increased sucrose yields by 700 to 1000 kg ha-1 only if the cane had been conventionally cultivated in either the prior plant-cane or second-ratoon crops. Over the three years where the treatments could be combined (plant-cane, first-, and second- ratoons) conventional tillage increased sucrose yields by 1200 kg ha-1, which equates to a $525 and $380 USD increase in gross and net revenue per hectare. A possible explanation as to why conventional cultivation of plant-cane affected the yields of all subsequent ratoons is that an adequate layer of soil is needed in ratoon crops to help protect underground buds from stresses such as cold temperatures, herbicides, excessively dry conditions, and harvester damage. To conclude, producers may consider minimum cultivation in the last two years of the crop cycle. Conventional cultivation in plant-cane is necessary to increase yield throughout a crop cycle. To insure optimum yields in clay soils over an entire sugarcane cycle, growers in Louisiana should not reduce cultivation frequency for the first three years of a four-year crop cycle.