| To alleviate the pressure of population growth and economic development of the demand for food,particularly in the circumstances of sustained reduction in arable land and the limited potential of increasing grain acreage,improving the crop yields per hectare has become the only way to protect our food security.In order to achieve high yield,the put of excessive nitrogen（N）fertilizers of farmer’s fertilizer practices（FFP）leads a way of agriculture development characterized by high input,high output and high environmental costs in our country.Therefore,changing the FFP,build trinity optimized nutrient management model of soil-crop-environmental is the urgent need to achieve synergies high yield of crop and high efficient of resource on modern agriculture production.In this study,the field experiments supplied with three different N nutrient management models were conducted in long-term location experiment station of Institute of Agricultural Sciences,Rugao City,Jiangsu Province in 2009-2013.The experiment design followed PK（only phosphorus potassium,control）,FFP and OPT（optimized nutrient management）,which includes four different OPT treatment:OF（optimal fertilizer）,OFR（OF reduce nitrogen）,OFRD/OFRS（OFR increase density/substitute nitrogen）and OFRDR/OFRRS（OFRD reduce nitrogen/OFR reduce nitrogen substitute nitrogen）,respectively.We mainly focused on the effects of different nutrient management models on rice biomass accumulation and distribution,yield and nitrogen use efficiency,canopy physiological ecology,nutrient fluxes and non-structural carbohydrates（NSC）during yield formation process,zinc biofortification,and large area of application and practice,in order to provide theoretical and practical of achieve rice high-yielding and high-efficient by optimized nutrient management.The major results are list as follows:1.The model of optimized N management is conducive to the formation a changes biological groups of rice on continuing high yield and high efficiency with different growth stages.The result showed that:（1）the biomass accumulation and distribution of FFP was significantly higher than PK and OPT before booting stage,but the FFP was significantly lower than OPT after flowering stage;（2）the biomass accumulation of leaf and sheath were first increased and then decreased,and the stems was relatively stable after flowering stage;the biomass accumulated of leaf and sheath of OPT were significantly higher FFP at tillering stage;（3）the biomass distribution of leaf and stem were gradually decreases,but the sheath was first increased and then decreased,the biomass distribution of the leaf affected by the different treatment displayed the following general trend:FFP>OPT>PK,with the sheath and stem was PK>OPT>FFP at total growth period;（4）the biomass accumulation of different leaf were showed that top 2>top 3>top 1,the sheath was top 1>top 3>top 2,while the stems was top 3>top 2>top 1 after flowering.2.The model of optimized N management could be rational allocation N accumulation and distribution of rice plant,collaboration to achieve the highest grain yield and its composition,the largest fertilizer use efficiency and minimum environmental secondary risks at total growth period.The results showed that:（1）OPT was significantly increased rice yield and the ratio of increase yield of OF treatment was 4.6%when decreased N rate 22.9%（OF）-56.0%（OFRRS）compared with FFP;（2）N accumulation and distribution of FFP were significantly higher than the PK and OPT at tillering stage,then the N accumulation was not significant between FFP and OPT,but the N distribution of OPT was significantly higher than FFP after booting stage,and acquisition a higher nitrogen harvest index;（3）the average value of PFPN,AEN and REN on OPT was higher than FFP 62.7%,62.8%and 70.2%,respectively.3.The model of optimized N management could be achieve HYHE,the reason was have a sustained physiological and ecological functions during total growth period.The results showed that:（1）leaf area index（LAI）was first increased and then decreased,the LAI of FFP was significantly higher than PK and OPT before booting stage,but the OF was always reach a greatest value after booting stage,and top2>top 3>top 1 of LAI at flowering;（2）there was a larger effect of leaf pruning degree on grain parameters,and the impact on inferior higher than superior,the ratio of contribution to one panicle or 103-grain weight of inferior and superior was stem+sheath and lest leaf>top 2 or top 3>top1;（3）the SPAD was gradually decreased after flowering,the SPAD of FFP was higher than PK and OPT before booting stage,the SPAD of flowering and harvest were top 2>top 3>top 1 and top 1>top 2>top 3,respectively;（4）the photosynthetic parameters gradually decreased,FFP was higher than OPT before booting stage,and top 1>top 2>top 3 of leaf photosynthetic parameters after flowering stage;（5）the canopy temperature（CT）of PK were higher than FFP and OPT during total growth period,the CT of OPT was higher than FFP before booting stage,but the difference was not significant after flowering,and there is a same consistent change at different times each day;（6）leaf water content（LWC）was gradually decreased with the growth period,PK was always lower than FFP and OPT,FFP was higher than OPT before flowering then the difference was not significant,and top 3>top 2>top1 of LWC after flowering;（7）leaf nitrogen concentration（LNC）was positively correlated with the LWC and net photosynthetic rate（Pn）,CT and LNC,LWC,Pn,transpiration rate（Tr）or biomass or yield was negatively correlated.4.The model of optimized N management has a significant effect the dynamic changes and spatial distribution of plants nutrients,and there was a significant correlation between the nutrients during the yield formation process.The results showed that:（1）the NSC content was always stem>sheath>leaf at flowering and harvest stages,the NSC content of leaf at harvest stage was increased 66.1%than flowering stage,but the NSC content of stem and sheath at flowering stage were decreased 48.2%and 94.4%than harvest stage,respectively;the NSC content was always gradually increased from top1 to top3 of rice organs,and the NSC content of rice organs were FFP>OPT>PK and FFP>PK>OPT at flowering and harvest stage,respectively;（2）the N content was leaf>stem>sheath at flowering and stem>leaf>sheath at harvest stage,respectively;the N content of leaf,sheath and sheath at harvest stage were decreased 75.5%,5.1%and 43.9%than flowering stage,respectively;the N content was significant declined from top1 to top3 of rice organs at flowering stage,but the N content was significant improved from top2 to rest of rice organs at harvest stage;the N content of rice organs were always OPT>FFP>PK at flowering and harvest stages;（3）the K content was sheath>stem>leaf at flowering and stem>sheath>leaf at harvest stage,respectively;the K content of leaf,sheath and sheath at harvest stage were increased-40.7%,-35.1%and 75.6%than flowering stage,respectively;the K content was significant declined from top1 to rest of rice organs at flowering and harvest stage,except leaf at flowering stage;the K content of leaf was FFP>OPT>PK,but the K content of sheath and stem at flowering and harvest stages,respectively;（4）there was a significantly negative correlated between N or K and NSC content of stem organs at flowering stage;there were a significantly negative correlated between N and NSC content,and positive correlated between K and NSC content of stem organs at harvest stage.（5）the grain filling rate of superior（814.07）was higher than inferior（498.07）,the grain N content kept stabilizing value and the grain K content was gradually increased during the yield formation process,and the N and K contents of superior were higher than inferior 4.1%and 18.6%,respectively.5.The optimized nutrition management by use zinc（Zn）and N fertilizers to obtain higher yield and higher grain Zn concentration of rice biofortification in low native Zn status.The results showed that:（1）the native soil Zn status was the dominant factor in determining the grain yield increase rate by Zn fertilizer application,the higher yield by use Zn fertilizer on the lower soil Zn status;（2）soil Zn application was more effective on the rice grain yield than foliar spray;however,foliar spray could more effectively increase the grain Zn concentration relative to soil application,and the grain Zn concentration affected by the application methods displayed the following general trend:soil application + foliar spray>foliar spray>soil application>control;（3）increase in the grain yield and Zn concentration by raising the N fertilizer amount from 200 kg/ha to 300 kg/ha,and the Zn application might increase the concentration and accumulation of N in rice plants;（4）there was a significantly positively correlated between grain Zn concentration and grain N concentration.6.The optimized nutrition management technology of high yield and high efficiency（HYHE）have a strong practical feasibility,that could be collaborate to improve rice yield,increase nutrient efficiency,enhance the nutrient contribution stage and reduce environmental risks,by combined nitrogen regulation of total and times,organic nitrogen fertilizer substitute,application trace elements and reasonable cultivation measures in large-scale application of Jiangsu Province.The result showed that:（1）the farmers average N rate,yield and nitrogen partial factor productivity（PFPN）of rice production was 336.7 kg hm-2,8131.8 kg hm-2 and 24.2 kg kg-1,respectively,and only 27.2%reached the HYHY according to farmer survey in Jiangsu province,China;（2）OPT of field experiment was significantly increase rice yield of 5.9%and PFPN of 37.6%when average reduction N rate of 22.9%compared to FFP,and achieved to HYHE based farmer research;（3）the average increased yield 5.6%of OPT than FFP within Jiangsu province in China Soil Testing and Formulated Fertilization database;（4）the model of nutrient contribution stage was build and optimized nutrient management in rice production is located in the advanced stage of nutrient contribution stage model. |
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