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针对目前已有群体叶面积指数(LAI)模拟模型形式多样、参数较多以及应用性不强等问题,对春玉米、水稻和冬小麦的LAI及出苗至成熟天数进行归一化处理,分别将最大LAI和出苗至成熟天数定为1,以相对LAI(0～1)和相对时间(0～1)为参数进行LAI动态模拟,筛选、建立了一个适用于这3种作物的相对化LAI动态模拟模型y=(a+bx)/(1+cx+dx2)。其中,春玉米y=(0.0134+0.3234x)/(1-2.774x+2.4178x2),r=0.9859**;水稻y=(0.0777+0.0205x)/(1-2.73744x+2.0484x2),r=0.9865**;冬小麦y=(0.0131+0.0035x)/(1-2.4515x+1.5273x2),r=0.9719**。利用该模型,自拔节期起就能够较准确地进行LAI的动态预测,其在春玉米、水稻和冬小麦上的准确度(以k表示)分别为1.050、1.0357和1.1168,精确度(以R2表示)分别为0.8728、0.9270和0.9254。3种作物整个生育期内模型的模拟值与测量值的精确度均在0.98以上,准确度达0.86以上,表明相对化LAI动态模型能够准确地反映作物群体动态变化。模型不仅可以计算出作物生育期间的平均LAI、总光合势,还能计算任一时刻的LAI以及任一时段的光合势;结合田间调查,还可得到作物生长期间的平均净同化率和平均作物生长率等产量相关的重要生理参数。根据作物群体中各光合生理参数与产量的关系,提出了3种作物进一步增产的可能途径。
In view of the variety of LAI models, the more parameters and the less applicability, the LAI and emergence to mature days of spring maize, rice and winter wheat are normalized to the maximum LAI and the number of days from emergence to maturation was set as 1. The relative LAI (0-1) and relative LAI (0-1) were used as parameters to simulate and screen LAI, and a relative LAI dynamic simulation was established for these three crops Model y = (a + bx) / (1 + cx + dx2). Among them, the spring maize y = (0.0134 + 0.3234x) / (1-2.774x + 2.4178x2), r = 0.9859 **; rice y = (0.0777 + 0.0205x) / (1-2.73744x + 2.0484x2), r = 0.9865 **; winter wheat y = (0.0131 + 0.0035x) / (1-2.4515x + 1.5273x2), r = 0.9719 **. Using this model, the dynamic prediction of LAI can be performed more accurately since the jointing stage. The accuracy (expressed in k) of spring LAI, rice and winter wheat is 1.050, 1.0357 and 1.1168, respectively. The accuracy ) Were 0.8728, 0.9270 and 0.9254, respectively. The accuracy of the simulated and measured values of the three models during the whole growth period were both above 0.98 and the accuracy was above 0.86, indicating that the relative LAI dynamic model can accurately reflect the dynamics of crop population Variety. The model can not only calculate the average LAI and total photosynthetic potential during crop growth, but also calculate the LAI at any time and the photosynthetic potential at any time. Combined with field investigation, the average net assimilation rate and average crop Growth rate and other important physiological parameters related to yield. According to the relationship between the photosynthetic physiological parameters and yield of crop groups, the possible ways of further increasing production of three kinds of crops were put forward.