Soil Profile and Site Characteristics Related to Winter Wheat Response to Potassium Fertilizers1
- Bernard E. Schaff and
- Earl O. Skogley2
Eighteen sites throughout Montana were selected to study soil and climatic factors that influence the response of winter wheat (Triticum aestivum L.) to K fertilizer. Rates of 0, 22, 45, 90, and 135 kg K/ha were applied with 45 and 56 kg/ha of N and P, respectively. The sites were characterized according to Soil Taxonomy classification parameters. Fourteen chemical and physical properties were determined for each genetic horizon and seven site characteristics were identified. A stepwise multiple linear regression analysis was used to determine the relationship of the chemical, physical, and site characteristics to percent yield response of winter wheat to applied K. The genetic horizon variables were analyzed by major horizon as well as by sequence of horizons. Statistically significant variables (p < 0.1) from the major horizon analyses were grouped with significant site characteristics in a combined overall analysis. Variables with the highest correlation to percent yield response in the combined analysis, in decreasing order, were: (i) mean annual soil temperature at 50 cm as derived from SCS estimates; (ii) moist consistence of the Ap; (iii) moist and (iv) dry consistence of the B horizon; and (v) the clay content of the ca horizon. For these five variables an R2 of 0.88 was obtained.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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