Improving Potassium Recommendations for Agricultural Crops

Abstract

As one of the three primary plant nutrients, K remains critically important in crop production. As an essential element for human nutrition, K intake today is inadequate in the diets of most of the world’s population. The need for improved cropping system productivity and the need for efficient use of all local resources and external inputs, including K and inputs with which K interacts, have greatly elevated the need to predict the capacity of specific soils to meet the K needs of specific crops. When that capacity is found insufficient, effective guidelines for K source, rate, timing, and placement decisions are needed. In the past few decades, the adoption of both hightech and low-tech approaches to site-specific nutrient management has increased the demand for accuracy and precision in K recommendations. Soil K evaluation has increased in importance in regions of the world where long-term negative K balances have increased the frequency of K deficiency in crops. In many areas, desired accuracy and precision are not attainable with current K recommendation approaches.