Effects Of Applying Potassium Fertilizer To Paddy Soil With Different Levels Of Potassium

Luliangyou996and Tianyouhuazhan was been used as provided materials. Paddies at different soil available K and different areas was been choosed as experimental field. Four treatments models was been set up in the experiment, which are high rate of potassium fertilizer (T1), optimum rate of potassium fertilizer (T2), low rate of potassium fertilizer, and no use of potassium fertilizer (CK), studied effects of rice yield and K use efficiency through planting double cropping rice in field. The results are showed that:1. Through analyzed the agronomic characters of double cropping rice, the results shows that the potassium fertilizer application can increase plant height, tiller number, and it can reduce invalid tiller number. The rice height or tiller number is not been significantly influenced by increased or decreased the optimized amount of potassium fertilizer application (T2).2. Through analyzed the flag leaf traits of double cropping rice in mature, the results shows that low potassium treat get more larger SPAD value; the flag leaf area of T1and T2treatment is significantly bigger than T3and CK, the biggest flag leaf area appeared in the T2treatment in middle-low soil available K rate, and T1treatment in high soil available K rate. The bigger flag leaf area, the better for assimilation and increment of yield.3. The application of potassium fertilizer increased rice yield, and comparing no potassium fertilizer treatment, the rice yield increased by4.08%-25.88%than the others treatments. Analyzed the yield components factor showed that the proper potassium fertilizer application can increase the rice effective panicles, grain number per panicle, and thousand kernel weight. The maximum rate of full grain appears in T2treatment and minimum in CK. The rate increased0.11%～2.39%than the others treatments. The best economical rate of potassium fertilizer (K2O) application is80kg/hm2and45kg/hm2under middle-low and high soil available K rate, respectively, however, under low soil available K rate, the best economical rate of potassium fertilizer (K2O) application is100kg/hm2in early rice and60kg/hm2in late rice.4. In different soil available K levels, the accumulation of rice to NPK reduced with the reduction of K application. The nitrogen (N) accumulation is91.70kg/hm2-126.34kg/hm2, phosphorus (P) is6.51kg/hm2～8.38kg/hm2, and potassium (K) is44.74kg/hm2～118.30kg/hm2. The maximum of Agronomic efficiency (AE) and Partial factor productivity (PFP) were20.57kg/kg and280.87kg/kg, respectively; and the minimum were1.99kg/kg and28.69kg/kg, respectively. AE and PFP are higher than other treatments, that its rate of potassium application is60kg/hm2,80kg/hm2, and15kg/hm2under low, middle-low, and high soil available K status, respectively.5. The contents of organic matter, nitrogen, phosphorus and potassium were not affected significantly by different rate of potassium application in the paddy soil after harvest.