Effect Of Different Combination Of Controlled Release Fertilizers In Yield And Quality Of Rice With Good Taste Quality

The experiment was carried out in rice and wheat technology comprehensive demonstration base of jiangsu province from 2017 to 2018 in the town of shengao,jiangyan district,Tai zhou city.Soil type is waterlogged paddy soiln and the preceding crop is wheat.Rice cultivars of Nanjing 9108 and Fengjing 1606 with good eating quality were adopted as experimental materials to study the effect of combined fertilizers(CF)on the yield,nutrient uptake and utilization and quality formation of rice.CF was firstly mixed with different release periods polymer-coated urea in particularly proportion and combinations,then blended with quick-acting fertilizer.The controlled release period of polymer-coated urea we used were 40 days(F),60 days(S),80 days(E),100 days(T1)and 120 days(T2).CF treatments are A1(10%F+40%E),A2(10%F+40%T1),A3(10%F+40%T2),B1(10%S+40%E),B2(10%S+40%T1)B3(10%S+40%T2).Furthermore,they also have 25%urea and 25%compound fertilizer.Conventional urea split fertilization is as control(CK).The main results were as follows:1.The yield of A2 and B2 was significantly higher than that of A1,B1,A3,B3 and CK because of increasing total spikelet number and stable percentage of filled grain and 1000-grain weight.In addition,the yield of B2 was the highest.The defect of A1 and B1 is too much nutrent was released during eariler stage so that rice hadn’t enough energy to keep high leaf area index and obtain adequate total spikelet number from heading to maturity stage,which resulted in reduction of yield.A3 and B3 had relatively high percentage of filled grain and 1000-grain weight,but they didn’t have enough panicle number so as to low yield.Under B2,the plant injury of rice with good eating quality was relieved quickly at the seedling stage with the assistance of controlled-release fertilizer and quick-acting fertilizer.Then rice began to tiller flourishly,which contributed to reach the expected number of panicles.With the ineffecient tillers died out gradually after the peak time of tillering stage,the appropriate number of effective panicles was obtained.From jointing to heading stage,leaf area index,crop growth rate,photosynthetic potential and net assimilation rate of rice were so excellent that it had large total spikelet number.In grain filling period,rice kept a high leaf area index because of slow leaf area attenuation rate so that large amount of dry matter production could be manufactured by photosynthesis to meet the demand of large storage capacity,then it could have high yield.2.Compared with CK,the amount of nitrogen accumulation,ratio of accumulation and nitrogen sbsorption rate of controlled release fertilizer combinations treatments was significantly higher from sowing to jointing stage.From joingting to heading stage,the amount of nitrogen accumulation of B2(2018)and B1(2019)was similar to CK,while nitrogen sbsorption rate of CK was almost the highest.From heading to maturity stage,the amount of nitrogen accumulation and nitrogen sbsorption rate of CK and B2 was higher than other treatments.Under B2,the amount of nitrogen uptake in jointing stage was medium,and the amount of nitrogen accumulation was high from jointing stage to heading stage as well as from heading stage to maturity stage.The total nitrogen uptake at maturity stage was significantly higher than that of other controlled release fertilizer combinations and CK.The amount of nitrogen uptaken by stems,sheaths and leaves was relatively high at heading and maturity stages.After heading,the amount of transferred nitrogen,apparent nitrogen transfer rate and nitrogen transfer contribution rate of leaves was at medium level,the same as stem and sheath;but the nitrogen accumulation in the panicle was significantly higher than that of other treatments.NHI(nitrogen harvest index),NRE(nitrogen recovery use efficiency),AE(agronomic nitrogen use efficiency),PE(physiological nitrogen use efficiency)and PFP(partial factor productivity of applied nitrogen)of B2 were significantly higher than those of other controlled release fertilizer combinations treatments and CK.3.Under the conditions of this study,compared to CK,controlled release fertilizer combinations treatments improved brown rice rate,milled rice rate,and head milled rice rate by 0.23%～0.39%,1.72%～2.28%and 4.79%～7.71%,which means CF can improve the processing quality of rice.Moreover,in controlled release fertilizer combinations treatments,the length,width and length-width ratio of rice were increased and chalky area,chalkiness and chalkiness rate of rice were 6.76%～16.21%,22.34%～47.87%and 7.92%～16.33%lower than that of CK.Nutritional and cooking taste quality of different treatments were various.In controlled release fertilizer combinations treatments,protein content of rice was 5.20%～5.68%lower than CK,mylose content,gel consistency and taste value of rice were 4.63%～6.14%,6.67%～6.73%and 5.66%～6.78%higher than those of CK;the value of peak viscosity,hot viscosity,final viscosity,and breakdown in RVA parameters of rice was higher than CK,and value of setback and peak viscosity time were opposite.