AbstractPotassium (K) fertilizer recommendations for annual crops in the USA are generally founded in soil test results. The goal of this chapter is to highlight additional plant-related traits that may impact crop responses to K fertilization. This includes the role of tissue testing, the influence of luxury consumption, genetic improvement of K use efficiency, genotype × environment × management interactions on K uptake and yield, response to foliar K fertilization, intraplant K cycling, fungal associations and K uptake, the influence of K on crop quality, and the role of K in abiotic stress tolerance. Recognizing the potential role of these plant factors may help reconcile response inconsistencies based solely on soil test information, and improve future K recommendations. Finally, we hope to highlight knowledge gaps and opportunities for additional integrated soil–plant K research.
Development of a soil test correlation and calibration database for the USA