Abstract
During variable rate operations, controller systems report information (as-applied files) about desired rates and real applied rates on georeferenced points along the machine tracks. These reports are useful for operation quality control but they have not been widely used to their potential. The goal of this study was to create a model to help analyzing as-applied files based on quantifying and locating off-rate errors and their probable related sources. The model calculates off-rate error at every point and classifies them as less than target rate, acceptable or over the target rate. Possible error sources are classified regarding three aspects: vehicle path position (inward, middle or outward), high rate change (step up or down) and vehicle acceleration or deceleration. A pulled type applicator (application 1) and a self-propelled applicator (application 2) were analyzed. An average of 30.6 % of the recorded points was considered application errors (10 % off the target rate). 70.5 % of them occurred on high rate change points on application 1 and 69.7 % on acceleration/deceleration points on application 2. The self-propelled applicator performed better during high transition rate than the pulled type which performed poorly when transition rate exceeded 10 %. The model determined the major and minor factors related to application error. It provided means to assess equipment limitations and its impact over the quality of application. The trials demonstrated its flexibility and how it can improve the use of as-applied files.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Chan, C. W., Schueller, J. K., Miller, W. M., Whitney, J. D., & Cornell, J. A. (2004). Error sources affecting variable rate application of nitrogen fertilizer. Precision Agriculture, 5, 601–616.
Cugati, S. A., Miller, W. M., Schueller, J. K., Schumann, A. W., Buchanon, S. M., & Hostler, H. K. (2007). Benchmarking the dynamic performance of two commercial variable-rate controllers and components. Transactions of the ASABE, 50(3), 795–802.
Fulton, J. P., Shearer, S. A., Higgins, S. F., Darr, M. J., & Stombaugh, T. S. (2005). Rate response assessment from various granular vrt applicators. Transactions of the ASABE, 48(6), 2095–2103.
Fulton, J. P., Shearer, S. A., Higgins, S. F., & McDonald, T. P. (2013). A method to generate and use as-applied surfaces to evaluate variable-rate fertilizer applications. Precision Agriculture, 14, 184–200.
Fulton, J. P., Shearer, S. A., Stombaugh, T. S., Anderson, M. E., Burks, T. F., & Higgins, S. F. (2003). Simulation of fixed- and variable-rate application of granular materials. Transactions of the ASABE, 46(5), 1311–1321.
Goense, D. (1997). The accuracy of farm machinery for precision agriculture: a case for fertilizer application. Netherlands Journal of Agricultural Science, 45, 201–217.
Lawrence, H. G., & Yule, I. J. (2007). Modeling of fertilizer distribution using measured machine parameters. Transactions of the ASABE, 50(4), 1141–1147.
Schumann, A. W., Miller, W. M., Zaman, Q. U., Hostler, K. H., Buchanon, S., & Cugati, S. (2006). Variable rate granular fertilization of citrus groves: spreader performance with single-tree prescription zones. Applied Engineering in Agriculture, 22(1), 19–24.
Tumbo, S., Salyani, M., Miller, W., Sweeb, R., & Buchanon, S. (2007). Evaluation of a variable rate controller for aldicarb application around buffer zones in citrus groves. Computers and Electronics in Agriculture, 56(2), 147–160.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Colaço, A.F., de Andrade Rosa, H.J. & Molin, J.P. A model to analyze as-applied reports from variable rate applications. Precision Agric 15, 304–320 (2014). https://doi.org/10.1007/s11119-014-9358-5
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11119-014-9358-5