Effects of water stress on rice yields and nutrients absorption under aerobic condition

PVC pumps filled with high-sandy soil were used to simulate groundwater table for controlling soil moisture. Effects of water stress on yields, nutrients absorption of rice were analyzed. Results show that both biological and economical yields of rice decrease with the increase of groundwater table ranged from 10 cm to 50 cm. Nitrogen absorption and Ca²⁺ and Cl^- accumulation of rice are accelerated under the reasonable groundwater table. Total soluble sugars and sucrose content of rice straw increase as well. However, phosphorus absorption, Mg²⁺ and Na⁺ accumulation of rice is reduced, and the transportation of K⁺ from the seeds back to the straws at ripening stage are retarded when groundwater table is low.