水盐胁迫条件下制种玉米水盐生产函数参数的推求

Calculation of the Water Salt Production Function Parameters of Seed Maize under Water Salt Stress

为了探究作物产量与水盐胁迫之间的关系,在石羊河流域开展制种玉米咸水非充分灌溉试验,引入作物水盐生产函数,利用田间实测资料推求作物水盐生产函数的参数,并对作物水盐生产函数的参数进行了率定和验证。研究表明,在参数率定与验证过程中,制种玉米各生育阶段的蒸散量和产量的实测值与模拟值吻合较好,各试验处理蒸散量的RMSE均在10 mm以下,蒸散量的MRE均在25%以内,产量的RMSE均在800 kg/hm2以下,产量的MRE均在15%以内,均在允许误差范围之内;率定与验证得到的作物水盐生产函数的参数分别为b=6.72、ky1=0.43、ky2=0.82、ky3=1.41、ky4=0.65、ky5=0.24。产量影响因子参数ky较好地反应了不同生育阶段水盐胁迫对制种玉米产量影响的敏感性。率定参数后的作物水盐生产函数能够较好地模拟研究区水盐胁迫条件下制种玉米的蒸散量和产量。研究结果可为研究区制种玉米咸水非充分灌溉制度的制定提供依据。

In order to explore the relationship between crop yield and water salt stress,field experiments were conducted under deficit irrigation with saline water in Shiyang Rive Basin.The crop-water-salt production function was introduced and the parameters were calculated,calibrated and validated based on the field experiments measured data.The results showed that in the process of parameters set and validation,the simulated evapotranspiration and yield were agreed well with the measured values of seed maize at different growth stages;the RMSE values were all lower than 10 mm and the MRE values were lower than 25%,which was in the allowable error range;the RMSE values were all lower than 800 kg/hm2 and the MRE values were lower than 15%,which was also in the allowable error range.The crop-water-salt production function parameters after calibration and validation were b=6.72,ky1=0.43,ky2=0.82,ky3=1.41,ky4=0.65,ky5=0.24,respectively.The yield influencing factors(ky)reflected sensitivity to the seed maize at different growth stages under water salt stress.The crop-water-salt production function can well simulate the seed maize evapotranspiration and yield under water salt stress after calibration and validation.The results can provide a basis for the establishment of inadequate salt water irrigation system for seed maize in the study area.