Simulation Research On Maize Yield Property Based On Field Climatic Real Time Monitor

With the increasing of crop yield,yield breaching becomes more difficult than ever. Higher productivity requires better crop performance,which accordingly requires precise crop husbandry.However,there are still large gaps in understanding crop performance and their relevant physiological factors and the following manipulation measures.As a consequence of which,quantified crop yield analysis is badly needed.On the basis of the"Yield Property Equation"put forward according to the"Three Combination Structure"crop yield analysis model,the quantitative analysis to the change characteristics for high-yielding population and proper ecological condition for yield formation of maize(Sea mays L.)in Northeast plain of China were studied.And the main results were as follows:(1)An extensively suitable NAR simulation model,y=a+bx+cx²+dx³+ex⁴,was developed with normalized NAR and crop growth duration data.And by means of which,the specific normalized model NARR=-0.01+10.54×(t)-39.72×(t)²+52.81×(t)³-23.37×(t)⁴(r=0.9461**) for spring maize was established.MNAR could be obtained by the equation, MNAR=(at+(b/2)×(t)²+(c/3)×(t)³+(d/4)×(t)⁴+(e/5)×(t)⁵)/t.Compared to other calculated equations of MNAR,MNAR=1/Tt*∑((NAR_i+NAR_i+1/2).t and MNAR=(EN.GN.GW)/(MLAI.D.HI),linear coefficients among them were between 0.59-0.99 and correlated significantly.So the results showed that NAR dynamic model provided a better method to caculate MNAR.It can be used in the equation of MLAI*D*MNAR*HI=EN*GN*GW,the equation was implemented the numeralization, hipping and indexation.The same meathod was used to simulate the DMA dynamic model, y=a/(l+be^-cx).The results showed that normalized NAR,DMA and LAI dynamic model provided a better description for crop population dynamics and put forward the possible ways to better use"Yield Property Equation"for higher crop yield.(2)On the basis normalized super high-yielding model of DMA,LAI and NAR and the differences of ecological factors,PAR,sunshine hour,temperature and rainfall,among regions,to determine or predict the simulated models for other regions.In the paper, temperature calibrated parameter refered to the model put forward by Longsiyu,which was P_T=y(T)/y(T₀)=(1+(T-T₀)/(T₀-T_min))^λ₁×(1-(T-T₀)/(T_max-T₀))^λ₂.By the same meathods of which,the sunshine hour and rainfall calibrated models were established,which was P_S =y(S)/y(S₀)=(1+(S-S₀)/(S₀-S_min))^γ₁×(1-(S-S₀)/(S_max-S₀))^γ₂and P_R=y(R)/y(R₀)=(1+(R-R₀)/(R₀-R_min))^φ₁×(1-(R-R₀)/(R_max-R₀))^φ₂,seperately.The maximum value,the minimum value and the optimization value of which were determined according to others' research results.Verified to Xinjiang,Neimenggu,Henan,Hebei,Shanxi,Shandong, Shenyang and Langfang,the the higherst,calibrated parameter appeared in Xinjiang,2002, which was 1.7451 and the loweat in Shanxi,2003,which was only 0.4216.the calibrated parameters varied with regions,years and sowing data.Accuracy was higher for low density, late sowing and early mature varieties for DMA calibrated model,high density,late sowing and middle-late mature were of high accuracy for LAI calibrated model,and high density,late sowing and early mature for NAR calibrated model.Which provided a new and simple simulated method.(3)On the basis of photo-thermal status and the resource utilizing efficiencies,super high grain yielding target were preliminary put forward at different high yielding districts.The radiation production potential(RPP)and thermal production potential(TPP)were calculated by means of photo-thermal status and crop production potential model,and the conceptions of radiation production potential equivalence(RPPE)and thermal production potential equivalence(TPPE)were brought forward.According to the values of RPPE and TPPE of favourable years,the super high yielding targets of different meteorologic years were preliminary put forward.Compared actual crop yield to the target yield,one can evaluate if the practice techniques suit for specific site or cultivar.Through which one can evaluate the cultivation levels between different Agroecological zones and different years.(4)According to the relationship among LAI and sunshine hours,temperature and rainfall, detemined the dynamic characteristics of leaf area index(LAI)and allocation characteristics of ecological resources under different yield levels.The results showed that the relative LAI models,with relative growth day(x₁),relative accumulated temperature(x₂),relative rainfall(x₃) and relative sunshine hours(x₄)as independences,fitted the rational formula y=(a+bx)/ (1+cx+dx²).Derivated to each modle,found that when the yield reached the 15499.86 kg·hm^-2,x₁,x₂,x₃ and x₄ was 1.43,1.41,1.44 and 1.40,respectively.Which meant high or super high yields could be achieved when x₁,x₂,x₃and x₄ were about 1.40.which could provide the scientific base for high-yielding cultivation,climatic resources proper exploitation and utilization and crop production potential excavation.(5)Analyzed the relationships between ecological factors(X)and yield property indexes (Y)in the yield property equation with the stepwise regression analysis.The ecological factors(X)were as follows,effective accumulated temperature(X₁),rainfall(X₂),sunshine hours(X₃),daily mean temperature(X₄),daily mean rainfall(X₅),daily mean sunshine hours (X₆),daily mean humidity(X₇),daily mean maximum temperature(X₈),daily mean minimum temperature(X₉),accumulated temperature in July(X₁₀),sunshine hours in July(X₁₁),mean temperature in July(X₁₂),mean sunshine hours in July(X₁₃),mean humidity in July(X₁₄), daily mean maximum temperature in July(X₁₅),daily mean minimum temperature in July (X₁₆),the number of days over 30℃(X₁₇),the ratio of growth days before and after silking (X₁₈),the ratio of accumulated temperature before and after silking(X₁₉),the ratio of rainfall before and after silking(X₂₀),the ratio of sunshine hour before and after silking(X₂₁). Clarified the relationship among ecological factors and yield property indexes.The ecological factors affected to yield primarily were effective accumulated temperature,daily mean temperature,daily mean minimum temperature,daily mean maximum temperature in July,the ratios of growth days,rainfall,accumulated temperature and sunshine hours before and after silking.Which provided theoretical instruction for maize cultivation.(6)The 3rd agrometeorological station has been finished developed by Zhaoming laboratory,the equipment was of multi-function,high stability and high accuracy.Using the sensing technology to collect the information of PAR,air temperature,relative humility,wind velocity,wind direction,rainfall and soil moisture.Using the SD card and GSM technology to achieve the data storage and communication at any time.Accoring to the meterorological information collected by weather station and maize growth data,the agricultural information management and making decision system was established,which achieved all the functions of agricultural information management,crop growth monitoring,simulation models prediction and cultivation management and making decision.