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Title: SOIL-TEST VARIABILITY IN ADJACENT IOWA FIELDS

Author
item Karlen, Douglas
item Cambardella, Cynthia
item Colvin, Thomas

Submitted to: International Conference on Precision Agriculture Abstracts & Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/26/1996
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: This study was undertaken to examine spatial variability of selected soil-test parameters for two adjacent field sites with known long-term soil and crop management histories. The study demonstrated significant farming system effects, although they were expected because of distinct differences in crop rotation and nutrient management practices. Semivariance analysis was used to determine the distance to which soil-test parameter values were spatially correlated and to estimate the strength of that correlation. Distinct differences in spatial dependence patterns were observed for the two farming systems. For the conventional system, soil properties exhibiting strong spatial dependence were spatially related across distances that spanned several map units and were correlated with intrinsic soil characteristics. Strong spatial dependence occurred at a smaller scale for the alternative site and appeared to be related predominantly to tillage and nutrient management strategies. These results have important implications for how and when site-specific information should be collected and interpreted.