Effects of Different Proportions of Nitrogen and Potassium Amounts on the Potassium Absorption and Utilization Efficiency in Direct-seeded Rice

In the conditions of three nitrogen amounts and three potassium amounts,the effects of different proportions of nitrogen and potassium amounts on the potassium absorption and utilization efficiency were discussed.The result indicated that the increase of application of potassium fertilizer amount improved the plant potassium accumulation,at the same level of nitrogen; the increase of application of nitrogen fertilizer improved potassium accumulation increasing by 30.61% ~ 37.30% at low level of nitrogen.Nitrogen fertilizer did not play a significant role in potassium absorption under high nitrogen level,but improved the potassium accumulation before spike differentiation.Increasing amount of nitrogen fertilizer could increase potassium percentage of total ratio in leavs,but reduced the potassium percentage of total ratio in culm,and had little effect on potassium distribution ratio in sheath and panicle.The potassium output rate of leaves decreased when nitrogen levels increased,the output rate of treatment of N2was nearly 9 percentage points less than that of treatment of N1.The potassium input rate of culm decreased significantly at high levels of nitrogen and potassium.The efficiency of potassium fertilizer in dry matter and grain production decreased when application of potassium fertilizer increased.Demand for potassium amount of one hundred kilograms of rice was the highest in the treatment of N2 but had no significant difference from treatment of N3.The effects of application levels of nitrogen fertilizer and potassium fertilizer on the potassium harvest index were not significant.