以生理生态过程为基础，构建了油菜光合作用与干物质积累的模拟模型。模型针对油菜特有的生态冠层结构，采用“三层模型”法，即通过对花、角果、叶三层分别计算光能截获和光合作用，利用高斯积分法计算每层的光合量而得出每日的冠层总同化量。模型充分量化了油菜生理年龄、温度、氮素、水分等因子对最大光合速率的影响，同时考虑了维持呼吸与生长呼吸的消耗。利用不同品种、不同播期、不同氮素水平下的干物质积累动态对模型进行了初步验证，结果表明模拟值与观测值吻合度较好，模型具有较强的机理性和预测性。
Photosynthesis and dry matter accumulation are major determinants of the final yield in crop production. Based on eco-physiological processes, a simulation model for photosynthetic production and dry matter accumulation was established for rapeseed. The model used a ‘3 layer model’ for calculating the radiation interception by the layers of flowers, pods and leaves and light absorption by pods and leaves. Gaussian integration method was used to calculate the photosynthesis of pod and leaf layers, and the daily total canopy photosynthesis which was that of all layers of green organs. The effects of physiological age, temperature, nitrogen and water deficit factors on maximum photosynthesis rate were adequately quantified. The model calculated maintenance respiration and growth respiration which consume some photosynthate. Partition index of shoot was quantified by physiological development time (PDT) to calculate shoot dry matter from plant biomass. Then, plant biomass loss due to freezing was quantified by temperature effect. Testing of the model for dry matter accumulation with the field experiments of different genotypes, sowing dates, and nitrogen levels showed a good fit between the observed and simulated data. Thus, the present model appears to be favourable on mechanism explanation and reliable prediction.
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