Effects Of Different Cultivation Management Modelsand Nitrogen Application On Yield Formation And Nitrogen Utilization In Winter Wheat

There is an urgent need to integrate individual technologies to createpractical cultivation management model in wheat production in order to achieveobjectives for high yield, high quality and efficient and ecological security. Under thefield conditions, two experiments of cultivation management models（the traditionalfarmers habits model was FM, the adjustment models were AM1,AM2,AM3）andnitrogen application rates (N0,N120,N180,N240,N360) were conducted withmulti-spike cultivars ping’an8, effects of different cultivation management modelsand nitrogen application on yield formation and nitrogen utilization of winter wheatwere studied at Wen County in Henan Province during2010to2012. The main resultswere as follow:1. Effect of different cultivation management models and nitrogenapplication on panicle development of winter wheatThe results showed that FM delayed panicle development of wheat, had less thetotal number of unit area flowers before the growth and development, and moreflorets at the after the growth and development, but the florets were early degradation,more degradation florets and less perfect florets. AM2and AM3promoted thedevelopment process of the wheat panicle, every model had same developmentprocess later, and AM2had less per unit area of the total number of florets and perfectflorets. The total number of per unit area florets about AM1and AM3were larger thanAM2, lower than FM, but the perfect florets had no significant difference and FMlater, and lower rates of degradation of per unit area perfect florets. The total numberof per unit area florets and perfect florets increased with increasing applicationamount of nitrogen, the perfect florets reached the maximum when nitrogen rate of240kg·hm-2, When the nitrogen rate was too high, raised the total number of per unitarea florets, to speed up the rate of perfect florets degradation.It showed thatreasonable cultivation management model, the optimum population structure andnitrogen fertilizer in the case to ensure that the more total florets, can delay the floretsdegradation rate, increase the number of perfect florets, and increase the number ofgrains per spike.The flower ovary development rates with flowers defeat bred grains are closely related in the conditions of cultivation management model. Different flowers ovarywidth of the different parts spikelets was increasing with the propulsion of the growthperiod, the performance was the central spikelets> lower spikelets> top spikelets.Theovary growth rate trend was broadly consistentat on the same spikelets differentPosition of different cultivation management models,the adjustment model ovarywidth was greater than FM.There was a highly significant positive correlation bothmature grain number and perfect florets of anthesis stages, five days after anthesis,thecorrelation coefficient was0.95,0.93, The final number of spikelets and perfect floretsof anthesis, five days after anthesis, spike dry matter accumulation and ear nitrogencontent were a significant positive correlation. Proving reasonable cultivationmanagement model and the optimum nitrogen rate improved dry matter and nitrogenaccumulation in wheat, increased per unit area perfect florets, thereby reduced perfectflowers abortion, had an important role to improve the grain number.2. Effect of different cultivation management models and nitrogenapplication on the material production of winter wheatThe results of this study showed that wheat group dynamics of differentcultivation management models and nitrogen fertilizer showed a single peak curve,with the growth stages, first increased and then decreased, the maximum number oftillers in the jointing stage; wheat biomass growth trends showed a "S" curve, biomassgrowth slowed from wintering to jointing stage, rapided growth from jointing stage toanthesis stage, slowed growth anthesis to maturity again of two years. FM was largerbefore the jointing stage, dry matter accumulation was less after the jointing; thepopulations of AM2had fewer tillers, less the amount of dry matter accumulationbefore the jointing stage, dry matter accumulation rapid after jointing, had a higherdry matter accumulation in the maturity. Compared to different nitrogen amount ofdry matter accumulation, The N360populations and dry matter accumulation werehigher than other treatments before the jointing stage, but the N240populations anddry matter accumulation was larger than N360after the jointing to maturity. Showedthat planting density and nitrogen fertilizer too much will lead to excessive tillers ofwheat in early growth stage, the interim population density of the fertility is too large,ineffective tillers mass extinction at late growth stage, resulting in waste of resourcesof the nutrients. Reasonable cultivation management model and nitrogen fertilizer cansignificantly improve the quality of wheat groups lay the foundation for higher grainyield of winter wheat. This study showed that pre-anthesis vegetative organs stored of dry mattertranslocation was allthe performance of Stem> sheath> leaf> cob+glume, the largestorgan of pre-anthesis vegetative organs stored of dry mattercontributed to seed wasthe stem and sheath, AM2improved the pre-anthesis vegetative organs stored of drymatter translocation and transport rates, accumulated more photosynthetic products ofpost-anthesis to ensure that the needs of the grain filling. The contribution rate ofpost-anthesis dry matter translocation to seed was larger than the contribution rate ofpre-anthesis dry matter translocation to seed; they were54.37%,45.63%and52.73%,47.27%. FM spike was significantly higher than the adjustment model, but the numberof grains per spike and grain weight were lower, grain yield of FM was significantlylower than the AM1, AM2, AM3; spike were less of AM2and AM3, but the numberof grains per spike and grain weight was significantly higher than FM, AM1, grainyield and harvest index were higher. Spike, grain yield and biomass of differentnitrogen application with increasing amount of nitrogen increased, reached themaximum when the nitrogen rate of240kg hm-2.3. Effect of different cultivation management models on nitrogenmetabolism of winter wheatThe result showed that, the flag leaf NR activity was higher in the anthesis stage,with reduced with the flowering days passage, flag leaf NR activity of AM3was thehighest for the year2010-2011. The flag leaf NR activity within15days after anthesisstage to maintain a high activity, followed by flowering days after the passage ofdecline, flag leaf NR activity of both AM1and AM3were higher in2011-2012.Theflag leaf GS activity showed a single peak curve changes, a peak was at10days afterflowering, GS activity of AM2was the highest, GS activity of FM was minimum;grains GS activity peaked at5days after flowering, and then decreased, astrong-grains and inferior grains GS activity showed a downward trend and AM2GSactivity was the higher in2010-2011. The2011-2012flag leaf GS activity peak at5,20days after flowering, GS activity of both AM3and AM1were higher; grains GSactivity peak in the10days after flowering, a strong grain of AM2, GS activity ofAM3was higher, Inferior Grains GS activity of AM2was higher; then decreased, andsmall peak was after about25days after flowering again, a strong grain GS activity ofAM1, AM3and Inferior Grains GS activity of AM2were higher. Reasonablecultivation management model can improve the ability of wheat flag leaf and grainnitrogen assimilation. 4. Effect of different cultivation management models on nitrogenutilization of winter wheatThe result showed that, with the advance of of the growth period, the amount ofnitrogen accumulation of wheat gradually increased, up to the the largest at maturity.Nitrogen accumulation of AM2was the largest, and nitrogen accumulation afterflowering contribution rate to spike was significantly lower than AM1and AM3in2010-2011. Nitrogen accumulation of AM3was the highest, and nitrogenaccumulation after flowering of AM2contribution rate to spike was significantlyhigher than AM1and AM3in2011-2012.Plant nitrogen accumulation about nitrogenrate of240kg hm-2at different nitrogen rate was the largest; nitrogen accumulationwas reduced when increased the amount of nitrogen fertilizer. Contribution rate ofnitrogen translocation to grain nitrogen accumulation was about80%, nitrogentranslocation and transport rates of the leaves were higher than others,transport ratesof AM3before flowering was highest.With the increase in the amount of nitrogenfertilizer, more nitrogen grain N uptake, excessive nitrogen application rate is notconducive to seed nitrogen accumulation.From the harvest index of wheat, harvestindex of AM2was less than AM1, AM3because of high nitrogen rate; recoveryefficiency and PFP decreased when increased the amount of nitrogen fertilizer, AM2was lower; with the nitrogen rate increased, nitrogen agronomic efficiency increasedfirst and then decreased. Nitrogen agronomic efficiency, recovery efficiency of FMwas lower.5. Effect of different cultivation management models on nitrateanalysis of winter wheatThe results of this study show that nitrate accumulation of FM was more,followed by the advance of the growth period gradually reduced;0-30cm and60-120cm soil nitrate accumulation of AM2and AM3were greater than FM and AM1in the maturity, analyze the reasons: AM2and AM3nitrogen rate were larger, resultedin soil nitrate with water seepage into the downward migration, reduced the nitrogenuse efficiency, increased the risk of leaching; higher nitrate content at AM10-60cmmeet the growing demand of wheat for nitrogen fertilizer, and also reduced the deepnitrate leaching.To increase production at the same time, effectively preventfertilization excessive with the infiltration of water into deep sand migration ofNO3-N, to prevent NO3-N leaching has important significance.In summary, compared AM1to FM, was less input, and suitable supply of fertilizer to meet the growth of wheat demand, wheat dry matter and nitrogenaccumulation were higher, yield and nitrogen use efficiency were higher, was thehigh-yield planting management model for the current wheat production application.Compared AM3to AM2(super high-yielding model), reduced the inputs, the yielddifference was not significant, for the future wheat production on the promotion of thehigh-yield planting management model again; soil fertility and production levels inthe local conditions, optimum nitrogen application range was180-240kg hm-2forwheat high production.