土壤-根系统养分迁移和吸收的数值模拟 Ⅱ.模型验证及参数的敏感性分析

Numerical simulation of nutrient transfer and absorption in soil-root system Ⅱ.Mathematical model verification and the sensitivity analyses of the parameters

用盆栽试验对玉米幼苗磷吸收进行了分析 ,并结合土壤和玉米根系磷运移和吸收参数的测定 ,用稳态吸收模型进行了计算。结果表明 ,随着土壤施磷量的增加 ,玉米幼苗含磷量和吸磷量明显提高 ;对于同一施磷水平 ,随着生长时间的增加 ,玉米幼苗的吸磷量增加的幅度较快 ;不同施磷处理玉米幼苗磷吸收的计算值和实测值均线性相关 ;养分吸收模型的玉米幼苗磷吸收模拟值与实测值具有很好的一致性 ,能很好地反映出幼苗吸收磷的变化趋势。单因素敏感性分析表明 ,影响作物根系磷吸收因素的大小顺序为 L>Cav>r0 >α>Deb>v0 >rx;某些参数的变化可以影响其他一些参数的原有水平 ;用图型分析法能准确地反映 r0 ,Deb,Imax,Cav,v0 和 rx

Experiments with pots were conducted for corn seedling P absorption,combining with survey of P transfer and uptake absorption parameter of soil and corn.This paper calculated P uptake by the steady state model.The results show that:there was an obvious increase of corn seedling P content and absorption P quantity with quantity increase of P fertilization application in soil;for the same P application level,corn seedling P absorption quantity increase is rapid with the increase of growth time;a linear relation was obtained with measured and calculated P uptake in different soil P application treatments,consistency that corn seedling absorbed and calculated P uptake can reflect well plant P absorption change tendency;Single factor sensitivity analysis shows,the size order that affects crop absorption P factors is L>C av >r 0>α> D eb>v 0>r x ;Method of Graphical analysis can reflect two dimensional and multidimensional mutual relations between r 0,D eb,I max , C av ,v 0 and r x etc.