Tutorial on Application of Manifold GIS Software for Precision Agriculture
Lesson 3 - Processing a Multi-Layer Yield History
Background
Yield maps represent probably the most valuable
data layers when it comes to identification of problematic field areas and
setting up spatially variable yield goals. In most instances, at least 5 years
of yield history is needed to make strong conclusions in terms of spatial and
temporal variability of field productivity. The preliminary step toward yield data
analysis is converting log files from proprietary binary code to an ASCII text
with columns corresponding to geographic latitude, longitude, yield and other
relevant attributes. During conversion, or right after it, each layer of yield
data should be adjusted for various combine dynamics delays and filtered to
remove all the records containing erroneous data. This can be achieved with the
number of options. Most agriculturally-oriented software packages with GIS
components (e.g., SMS, FarmWorks, FOViewer, etc.) can be used to open binary
yield files and to extract data corresponding to individual fields. Some
portion of data filtering can be accomplished during this conversion. However, additional,
more advanced, data processing should be pursued to recognize less obvious
problematic records and assure higher quality of the resulting yield maps.
Yield Editor and Yield Check are two examples of free software designed for
advanced filtering of yield data. Clean layers of yield data should be
integrated through the averaging of normalized surfaces or various
classification procedures aimed at the establishment of management zones. This
lesson provides an example of yield history analysis based on two years of corn
and three years of soybean records.
Objectives
- Remove erroneous yield data records
- Process yield data corresponding to individual growing seasons
- Develop a yield goal map
- Establish an elementary yield classification routine
Please e-mail vadamchuk2@unl.edu to obtain the password allowing complete access.
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