Thursday, November 8, 2007 - 10:00 AM
331-6
Development and Application of A Potash Decision Support System.
In many parts of the world, potassium (K) has been considered a nutrient of relatively minor importance. As a result of this misconception, systematic research programs designed to assess the importance of the factors that affect crop response to potash (soil, climate, crop variety, K rate, etc.) have often not been considered. Nevertheless, as intensity of crop production increases, recycling of crop residues decreases, crop demands for potash become more apparent, and the limitations of traditional approaches to estimating K requirements become evident. Conversely, in some countries, farmers are encouraged to use NPK fertilizers in soils that have adequate K, without any apparent benefits from K fertilization. These limitations become most pronounced in developing countries where agronomists are often unable—through lack of funds, research facilities, or training—to mount the extensive field research programs necessary to prepare accurate regional fertilizer management strategies. A potash decision support system (KDSS) with a dynamic model that takes into account the key factors that influence soil K transformations (associated with chemical fertilizers, organic sources, and plant K uptake) is presented as an option for regions where adequate soil, climate, and crop data are available. KDSS also uses a simpler approach based on crop K demand, yields from minus K plots, and management for data deficient areas. The latter approach is also adequate for K maintenance recommendations.
Audio File