Effect of Low Potassium Stress on the Nutrient Uptake and Distribution of Two Rice Varieties with Different Potassium Sensitivity

Results obtained from pot and field experiments showed that potassium deficiency stress restrained the growth of 81394, a variety sensitive to potassium deficiency, which had the genetic characteristics of high dry products and low potassium concentration. But different potassium application had little effect on the growing and potassium accumulation in Fujiandao, a variety tolerant to potassium deficiency. The K use efficiency (KUE) of Fujiandao was higher than that of 81394 under K deficiency condition at earlier growing stage, while it was just the opposite under potassium sufficient condition or at later growing stage. The K efficiency (KE) of Fujiandao was always higher than that of 81394. The nitrogen content and N/K were higher under K deficiency condition, which caused the nutrient unbalance in rice. Such appearance of 81394 was more distinct than that of Fujiandao. Potassium deficiency could also promote the sodium uptake and accumulation, especially in the root of Fujiandao, which meant sodium and potassium substitution in the root should be one of the mechanisms of high potassium deficiency tolerance.