改进CERES-Maize模型在玉米膜下滴灌模式下的适用性

针对CERES-Maize模型没有覆膜处理模块而无法从机理上实现对覆膜玉米生长发育及产量形成过程进行模拟的问题,依据作物生长发育的有效积温原理,利用膜地增温对有效气积温的补偿效应,量化覆膜地温对气温的补偿值,改进模型气象模块中的气温输入数据,同时将模型中影响腾发量及水量平衡计算的冠层能量消光系数K调整为0.5,构建了适宜于膜下滴灌的改进型CERES-Maize模型,并依据2014和2015年膜下滴灌玉米田间试验数据对改进模型进行验证.结果表明覆膜地积温对气积温的增温补偿系数C_c:播种-出苗期为0.45,出苗~抽雄前期为0.20;随着K降低,地上生物量与籽粒产量的相对误差绝对值ARE降低并趋近于0;改进后的模型能够较好地模拟覆膜玉米开花期天数、成熟期天数、收获期地上生物量和籽粒产量,其模拟值和实测值的ARE分别为0.58%,0.37%,7.65%和16.95%,相对均方根误差RRMSE分别为0.84%,0.51%,8.75%和17.50%.

Applicability of improved CERES-Maize model under mulch drip irrigation of maize

An improved CERES-Maize model was generated to simulate the growth and yield of maize under mulch drip irrigation. Based on theory of effective accumulation temperature and compensating action on effective cumulative ambient temperature by soil temperature increase in mulched maize fields, the input data of ambient temperature for the modelled meteorological module were improved by quantifying the compensation value on the ambient temperature. The canopy energy extinction coefficient, K, which can affect evapotranspiration and water balance, was adjusted to 0.5. The improved model was validated with two-year experimental data of maize under mulch drip irrigation in 2014-2015. The results show that the compensatory coefficient of cumulative soil temperature, C_c, in plastic film mulch field is 0.45 from sowing to emergence stages, and 0.2 from emergence to tassel stages. The absolute relative errors(ARE)of above-ground biomass and grain yield decrease and approach zero with decreasing K. The improved model can simulate flowing days, mature days, biomass and maize yield under mulch drip irrigation quite well with AREs of 0.58%,0.37%,7.65% and 16.95%, respectively, and the corresponding relative root mean square errors(RRMSE)are 0.84%,0.51%,8.75% and 17.50%, respectively.