Effects Of Slow-controlled Release Fertilizer Types And Their Fertilization Methods On The Formation Of Yield And Quality In Early Ripen And Late-season Rice

The experiment was conducted in Changshu Research Institute of Agricultural Science in Taihu area of Jiangsu Province from 2015 to 2016.Soil type is waterlogged paddy soiln and the preceding crop is wheat.Early maturing and late japonica rice cultivars of Yongyou 1538 and Changnongjing 8 were adopted as experimental materials.Three types of slow-controlled release fertilizer[polymer-coated urea(PCU),sulfur-coated urea(SCU)and urea formaldehyde(UF)]and two fertilization managements[slow-controlled release fertilizer as basal fertilizer with conventional urea as tillering fertilizer(BT)and slow-controlled release fertilizer as basal fertilizer with conventional urea as panicle fertilizer(BP)]were used with conventional urea split fertilization as control(CK).The main results were as follows:1.The yield of different types of fertilizer showed the trend of PCU>SCU>UF.Compared with PCU,nitrogen of SCU or UF released mainly at the early and middle stage of growth,which resulted in the insufficient number of grains perpanicle in the later stage of growth.The total spikelet per area was decrease significantly.The photosynthetic potential of leaf decreased from heading to maturity.In Yongyou 1538,the yield of different fertilization methods showed the trend of BT>BP.The photosynthetic potential and dry matter accumulation increased at the stage of heading to maturity,and the number of effective panicles,grains per panicle,total spikelet and yield increased significantly.In Changnongjing 8,there was no significant difference in yield between BT and BP.The high yield of rice could beachieved through increased number of effective panicles in BT treatment or through the increased number of grains per panicle in BP treatment,respectively.Compared with CK.In terms of plant morphology,BT can reduce plant height.BT decreased leaf base angle and sag degree.BT also can improve light receiving attitude.BP have no significant effect on plant height.It can increase leaf length、drape degree and shorten basal internode length of upper three leaves.It also improved the ability to resist lodging.The yield and material accumulation of slow-controlled release fertilizer under BP fertilization treatment were superior to CK.Among different types of slow-controlled release fertilizer,PCU had the most obvious effect on increasing yield and labor saving.2.With two methods of N fertilization,the amount and ratio of N accumulation were relative high during the period from sowing to jointing in the treatment of BT,while they were relative high during the periods from jointing to heading and from heading to maturity in the treatment of BP.Meanwhile,the rate of nitrogen absorption and the SPAD value of the sword leaves at late growth stage of rice were increased in BP treatment.The nitrogen release of three types of slow-controlled release fertilizer was different in different growth stages of rice.The nitrogen accumulation and nitrogen absorption rate of UF were highest from sowing to jointing stage.SCU and PCU were similar in joint-heading stage.They were significantly higher than UF.While the PCU was highest in heading and mature stage.Phosphorus,potassium absorption and nitrogen fertilizer absorption had synergistic effects.The amount and ratio of nitrogen accumulation of each growth stage were significantly positive correlated with phosphorus and potassium accumulation.Among different types of slow-controlled release fertilizer,PCU was longevity at the early and middle growth stage of rice.And topdressing urea at later growth stage can ensured the nutrient absorption of rice at different growth stages.To increase chlorophyll content,maintain photosynthetic capacity and prevent premature senescence,so as to increase the synergistic absorption of phosphorus and potassium.3.Under the experimental conditions,there was no significant difference between slow-controlled release fertilizer and CK of processing quality on rice.Compared with BT,the rate of chalkiness,the area of chalkiness and the degree of chalkiness were significantly increased,and the protein content in rice was increased,and the nutritional quality was improved.The protein content was negatively correlated with the taste value(R2=0.996**),so the food taste value decreased significantly.In cooking and eating quality,amylose content and gel consistency decreased,the highest viscosity,hot viscosity and breakdownvalue of RVA decreased.Among the three types fertilizer,PCU significantly increased the chalkiness rate,chalkiness size and chalkiness,protein content,the content of amylose and gel consistency,decreased the quality of taste,the peak viscosity,hot viscosity,breakdownvalue,and the decrease of cooking taste quality.Therefore,SCU and UF could improve the cooking and taste quality of rice significantly under the fertilization method of BT.The rice quality and yield of PCU was close to CK.