Submitted to: International Conference on Precision Agriculture Abstracts & Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: June 26, 1996
Publication Date: N/A
Technical Abstract: Crop yield patterns vary from across fields and year to year. These yield variations occur because of complex interactions between the crop and soil, weeds, insects, and disease. A basic tenet of soil scientists working in precision farming is that by identifying the soil properties that limit yield, management practices can be modified to reduce or eliminate their effect on yield. In a companion study (Colvin et al., this conference), we used six years of yield data to determine the yield patterns within a central Iowa field. In this study, we have tried to identify the soil properties that may explain these observed yield patterns. A range of soil physical, chemical, and biological properties were measured from predetermined high, low and erratic yielding locations in the field. Standard statistical tests were applied to screen for the factors best correlated to the yield pattern. The primary determinant of yield is the interaction between precipitation and aggregate stability (which influences water entry vs. runoff and water holding capacity). After screening for this interaction, identifying the next most limiting soil properties is much more difficult.