Construction And Verification Of Function-Structure Model Of Millet Based On Organ Scale

Millet is one of the crops with a long history of cultivation in China.As a characteristic minor grain crop in Shanxi Province,millet has the advantages of drought tolerance and easy storage.It is a typical environment-friendly crop under dry farming conditions.In the process of developing precision agriculture,the construction of crop growth model can accurately simulate the relationship between crop growth and environmental conditions,which provides an important means for realizing sustainable agricultural development.Based on the feedback mechanism of physiological ecology and morphological structure in the plant function structure model,this paper takes Jingu 21 as the research object,takes the growth cycle as the time step,and the metamer as the basic structural unit to quantitatively study the relationship between millet growth and external environment,and constructs the function structure model of millet based on organ scale.In this paper,the model parameters were extracted from the sampled data of millet in the agricultural high-tech area of Wujiabao Village and the algorithm was programmed to realize it.Finally,the growth of millet in the Dongyang experimental site was simulated,and the measured data was compared with the simulation results to achieve model verification.The research content and conclusions of this paper are as follows:1.Field experiment: plant millet in the field,record crop growth conditions and meteorological data,take destructive sampling regularly and quantitatively,and measure the morphological data and biomass of each organ of millet.2.Model construction: Determine the basic unit of millet growth based on the observation data of millet field experiment,establish the relationship between metamer and effective accumulated temperature,and construct the topological structure model of millet;use sink strength to represent the assimilation of different types of millet organs ability,the expansion rate is used to indicate the ability of the same type of millet organs to obtain biomass in different periods,and the product of sink strength and expansion rate was used as the theoretical requirement of biomass for each organ of millet,and the biomass allocation and accumulation model during the growth and development of millet was constructed.According to the allometric rules during the growth and development of different organs of millet,a morphological model of millet organs was constructed.3.Model parameterization and realization: the relationship between metamer and effective accumulated temperature was determined in the topological structure model of millet,and the development parameter was obtained as 0.0286 ℃^-1·d^-1,and the effective accumulated temperature corresponding to one growth cycle was 35 ℃·d;based on the observation data of millet field experiment and gradient descent method,the implicit parameters of millet biomass allocation model were obtained;according to the relationship between internode volume,leaf area,ear and dry matter weight of foxtail millet,the morphological parameters of foxtail millet organ morphological model were obtained.The parameter of stem node morphological model was 4.0195.The morphological model parameter of the leaf is 0.0064.The morphological model parameters of grain ears are 2.9261,17.26.The C++ programming language and the Visual Studio development environment are used to simulate the growth of millet.4.Model verification: Taking the millet sampling data from the Dongyang Experimental Demonstration Base of Shanxi Academy of Agricultural Sciences as the model verification,the biomass simulation values of the millet internodes and millet leaves at different leaf positions at the 10th GC and13th GC of the Dongyang experimental site were selected for comparison with the real values measured in the experiment.The programming software was used to simulate and output the biomass distribution and accumulation results and morphological and structural changes of the above-ground organs of the Dongyang Experimental Millet.The results show that the simulation results are generally in good agreement with the real data,verifying the effectiveness of the function-structure model of millet,and can better describe the growth and development process of the upper part of millet.