Summary Of Soil Potassium Status And Research On Double Cropping Late Rice Response To Potash Application In Jiangxi Province

Potassium is a necessary nutrition element for the growth and development in rice;Appropriate potash fertilizer applying and potassium management strategy is one of the preconditions for high and stable yield in rice.As a result,more and more researchers focus their research intersects on the recommended applying of potash fertilizer and potassium management strategy in different rice varieties at different areas.Jiangxi is one of the main rice producing areas in China,and it is also a region with serious soil deficiency in China.Therefore,it is very important to investigate the potassium supply of paddy soil and study the effects of potassium fertilizer in rice in Jiangxi province.This study analyzes the soil potassium status of 1985 and 2015 in paddy soil of Jiangxi province.Using the rice variety Wufengyou T025 as experimental material,we studied the growth and development of rice under different applying of potash fertilizer and potassium management strategy condition in different areas.The main research conclusions are as follows:1.In Jiangxi province,the proportion of lack available potassium in paddy soil was decreased from 40.63% in 1985 to 20.57% in 2015.In 1985,the proportion of lack total potassium in paddy soil in Jiangxi province is 19.07%,while in 2015,there is no total potassium deficiency in paddy soil in Jiangxi province.2.In 2015,the most serious situation of lack available potassium in paddy soil is Ganzhou city and the smallest proportion of lack available potassium in paddy soil is Yingtan city.In Ganzhou city,the proportion of the available potassium deficiency in paddy soil was 34.74%.In Yingtan city,the proportion of the available potassium deficiency in paddy soil was 5.29%.3.With the increasing of K rate,the yield of rice,the number of effective panicles and the setting percent was increasing in Taihe,while the dry matter accumulation in the mature period increased first and then decreased.In Yongxiu,The rice yield is increasing,but the dry matter accumulation in the mature period increases first and then decreases.With the increasing of K rate,the leaf area index of rice is increasing in Taihe,but there is no obvious rule in Yongxiu.Both the agricultural utilization rate and the partial productivity of rice potash fertilizer were decreased with the increasing of K rate in Taihe and Yongxiu.4.With the ratio of splitting K at panicle initiation increase,there was no significant change in rice yield at Taihe and Wannian,while it was increased and then decreased in Yongxiu.The result in dry matters accumulation at maturity was similar with the yield change rule in Wannian and Yongxiu.There was no significant change in leaf area index of each test site.With the ratio of splitting K at panicle initiation increased,the potassiumaccumulation at maturity in rice shows a slightly increase.Concluding all the experimental results,it shows that the soil potassium content of paddy soil in Jiangxi province has been improved,and the proportion of soil potassium deficiency is decreasing.In Taihe and Yongxiu,the recommended KCL rates for double cropping late rice all were 210kg/hm 2.The recommended ratios of splitting K(basal fertilizer:tillering fertilizer:panicle fertilizer)for Wufengyou T025 were 4:2:4 in Taihe and Wannian,while in Yongxiu it is 5:2:3.