Author
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Johnson, Richard |
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Richard Jr, Edward |
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Submitted to: Sugar Journal
Publication Type: Trade Journal Publication Acceptance Date: 3/14/2005 Publication Date: 4/20/2005 Citation: Johnson, R.M., Richard Jr, E.P. 2005. Precision Agriculture Research in Louisiana Sugarcane. Sugar Journal. 67(11):6-7. Interpretive Summary: Louisiana sugarcane producers have faced increased economic pressure in the past several years due to crop yields that were below normal. Growers must find ways to increase efficiency, while maintaining or improving yields and avoiding adverse environmental impacts. The techniques used in a Precision Agriculture (PA) management approach which include “on-the-go” yield and soil property mapping, soil grid sampling, and variable rate application of lime and plant nutrients, may offer producers a system to accomplish this task. We demonstrated that significant variability exists in commercial Louisiana sugarcane fields with tonnage varying up to 4.5 times and sugar yield varying up to 5 times within one field. The variability was present in all years and for all crop ages from plant-cane to 6th ratoon. Using grid sampling we also demonstrated that significant variability in soil acidity existed with pH values ranging from 4.9 to 6.5 in the commercial field sampled. This corresponded to a variation in lime requirement from 0 to 2.24 T/ha and ultimately a reduction of the overall lime requirement for the field by 50%. This work demonstrated the need for developing a dependable and fairly accurate yield monitor for the chopper harvesters currently used in the Louisiana industry. Coupling of the yield monitor with other PA management techniques may increase the production efficiency of the Louisiana sugarcane producers while lessening the impact of the crop’s culture on the environment. Technical Abstract: Louisiana sugarcane producers have faced increased economic pressure in the past several years due to crop yields that were below normal and increased production costs. Growers must find ways to increase efficiency, while maintaining yields and avoiding adverse environmental impacts. The techniques used in a Precision Agriculture (PA) management which include yield and soil property mapping, soil grid sampling, and variable rate (VR) application of lime and plant nutrients, may offer producers a system to accomplish this task. We utilized a sugarcane chopper harvester and a “weigh-wagon” to show that significant yield variability exists in commercial Louisiana sugarcane fields with tonnage varying up to 4.5 times and sugar yield varying up to 5 times within one field. The variability was present in all years of the study and was observed for all crop ages from plant-cane to 6th ratoon. We have also utilized soil grid sampling techniques to document significant variability in soil acidity in several Louisiana sugarcane fields with pH values ranging from 4.9 to 6.5 in one field. This corresponded to a variation in lime requirement from 0 to 2.24 T/ha. In another part of the study we determined that a 0.4-ha grid size for soil sampling was required for mapping purposes and not the more commonly used 1-ha grid to more accurately target nutrient application thus avoiding under or over-application and minimizing adverse environmental impacts. Using such a soil grid map and a and a VR lime applicator, we demonstrated that similar yields can be obtained while simultaneously reducing the total amount of lime applied. For several fields investigated over half of the field did not require lime using grid sampling and VR application methods, compared to the entire field when fields were sampled and lime applied using traditional means. This research suggests that PA management techniques may offer Louisiana sugarcane producers’ viable methods to increase efficiency, maximize yields and decrease costs. However, if PA techniques are to be effective in culturing sugarcane, a dependable and fairly accurate harvester-mounted yield monitor will have to be developed. |
