Did yields increase in fields that tested low for soil P and K?
As expected, yield increases were seed in fields testing low in P and K, but sometimes also in fields testing Optimum or higher due to reasons difficult to identify. Soil test results, tissue test results and climatic conditions didn’t support strong conclusions, but suggested that conditions in which a response to foliar fertilization was more likely to include ridge-till and no-till fields and slow early plant growth and P or K uptake due to cool early temperatures and excessive rainfall. Therefore, conditions that inhibit root growth and/or nutrient uptake early during the growing season (except drought) increased the likelihood of a yield response. What about including fungicide with foliar fertilizer application? Five field trials conducted in 2005 and 2006 that studied foliar fertilization and fungicide application alone or in a spray mixture produced even more disappointing results for foliar fertilization. Eight treatments were a non- treated control, four foliar fertilization
