Potassium uptake and recovery by an upland rice-soybean rotation on an Oxisol.

(...) Six K treatments supplied 0 to 240 kg K ha −1 to each crop and lime treatment. Potassium fertilization increased grain yields of rice and soybean and K content of grain and stover of both crops. With both crops a large proportion of the K was present in the stover. Liming had no effect on K accumulation of rice grain; an inconsistent effect on K accumulation in rice straw; and significantly increased the K content of soybean grain and stover. Upland rice was very efficient in utilizing K applied to that crop as well as residual soil K from previous fertilization