【摘要】 通过不同土壤条件下幼苗磷吸收实测值与机理模型预测值的比较 ,检验了几种养分吸收机理模型对玉米与大豆幼苗磷吸收的预测能力 ,同时探讨了解析解模型与数值解模型的主要模拟误差来源及其改进方法。研究结果表明 :供试 3种机理模型均能较好地反映玉米与大豆幼苗的磷吸收变化情况 ;3种机理模型中 ,以建立于解析解基础上的SC模型的预测能力最低 ,而以考虑了根毛作用的C2模型的预测能力最强 ;影响机理模型预测能力的重要因素是土壤供磷水平 ,土壤供磷水平低时机理模型的预测能力明显降低 ;土壤养分缓冲容量b2 参数的选用能在一定程度上使数值解机理模型计入根介入的根际磷活化与吸收 ,从而提高数值解机理模型在土壤低供磷水平时的磷吸收预测能力 ;解析解模型的误差校正方程可明显提高其预测能力。更多还原

【Abstract】 By comparing the measured and model-calculated P absorbed by seedlings, the verification error sources and improvement of several mechanistic models of nutrient uptake in the process of P absorption by maize and soybean under different soil conditions were studied. The results showed that: (a)all of the three kinds of selected models can reflect the changing trend of P uptake by seedlings of Maize and soybean, (b) among the three selected models, the predicting ability of SC model is the poorest, and that of C2 model including the effect of root hairs is the strongest, (c)the most important factor influencing model’s predicting ability is soil P level, and the model’s predicting ability will become poor evidently when soil P level lowers, (d)by choosing the b2 model parameter, the root-mediated P activation and absorption could be included to a certain extent in the simulated P uptake by seedlings, and therefore the ability of selected mechanistic model based on numeric solution to predict P uptake by seedlings under p-stressed situation is enhanced, (e) the correcting equation for simulating deviation of the model based on analytical solution can markedly improve its predicting ability. \;更多还原