Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: July 23, 2003
Publication Date: October 1, 2003
Citation: Shanahan, J.F., Schepers, J.S. 2003. Integrating management zones and on-the-go N sensor. American Society of Agronomy Abstracts. #432096. CDROM. Technical Abstract: Numerous researchers have advocated use of management zones (MZ) as a method for variable application of crop inputs like nitrogen (N) to corn and other crops. Various approaches for delineating MZ, involving the aggregation of various landscape attributes like soil color, topography, and apparent electrical conductivity (ECa) using sophisticated statistical techniques, have been suggested. Our research along with others indicates that landscape attributes can be used to delineate MZ that consistently characterize spatial variation in soil chemical properties. However, it appears that this method is less consistent in characterizing spatial variability in crop yields across temporal variations in climate. The relative importance of various soil properties in predicting yield depends on the most limiting factor(s), which in many situations is water. Given the effect of temporal variability on crop responses, it seems unlikely that a static soil-based concept alone will be adequate for variable application of N. Alternatively, a better strategy might be to combine the use of MZ along with crop-based in-season remote sensing systems to more efficiently apply N. This presentation will discuss integrating the use of soil-based approaches like MZ along with crop-based, on-the-go sensor approaches as a means for improving the feasibility of variable N applications to corn.