Preliminary development and testing of DRIS soil norms for soybean production

Publisher Website
Google Scholar
Abstract
The Diagnosis and Recommendation Integrated System (DRIS) has proven to be a useful tool for the identification and correction of nutrient limitations in plants. The basic tenets of the approach as they apply to development of soil norms are discussed. Diagnostic norms based on Mehlich I extractable P, K, Ca, and Mg were developed for coarse‐ and fine‐textured Ultisols employing data banks containing 1000 and 1500 observations, respectively. Differences in “optimum” nutrient ratios between the two soil types appeared to be due to regional liming and fertilization practices based on the amount of clay in the plough layer. DRIS soil norms accurately diagnosed nutrient limitations at low yield levels but were not successful at higher yield levels, indicating that factors other than those considered may be more limiting. Soil nutrient balance is not critical in determining yields on the highly weathered soils of the southeastern United States at yield levels less than 3,000 kg ha‐l except when the level of some nutrient is excessive.