Plant Mapping Potassium in Rice Tissue: What Part to Sample When?

Introduction Proper potassium (K) nutrition is critical for maximizing rice grain yields. K is very mobile within the rice plant. Older leaves are scavenged for the K needed by younger leaves. Recent studies at the Missouri Rice Research Farm have shown that supplemental K can be supplied to the rice plant as late as Internode Elongation (IE) and still increase rice grain yields. In this same study whole plant K analysis at IE was better correlated to yield than flag leaf analysis at early boot. Profitable rice production hinges on accurate, reliable, and relevant information about plant-soil interactions. A review of the available literature shows that no consistent methodology has been developed correlating K determinations in rice plants to rice grain yields. This study will attempt to determine which part of the rice plant and at which growth stage tissue samples should be collected.