【摘要】 【目的】确定夏玉米倒伏后农田蒸散量变化特征。【方法】郑州农业气象试验站2016年8月25日出现夏玉米大风倒伏现象,利用正常年(2017年)气象数据、作物观测数据和涡度观测数据,通过Penman-Monteith模型(P-M模型)模拟并检验夏玉米正常生长年型蒸散量变化特征,优化参数模型,计算P-M模型模拟值与实测值的最优拟合度。然后根据率定参数的P-M蒸散模型,利用田间调查数据,以未倒伏的植株参数为假定夏玉米没有发生倒伏,进行农田蒸散量模拟,模拟结果作为蒸散量对照值(P-M_N);以实际倒伏后的植株参数,进行农田蒸散量模拟,模拟结果为实际倒伏蒸散量(P-M_L)。【结果】正常年型蒸散量模拟值与实测值具有较好的一致性,模拟绝对误差为0.005,相对误差为10.7%,均方根误差和一致性指数分别为0.019、0.980,说明模型具有较好的预测性。在倒伏年,倒伏后蒸散量模拟值与实测值的绝对误差和相对误差分别为0.002 mm/30 min、2.9%,均方根误差为0.001,一致性指数为0.98。【结论】乳熟期夏玉米倒伏后农田蒸散量显著降低,根据P-M模型计算结果,夏玉米倒伏后农田蒸散量降低0.019 mm/30 min,日平均降低0.68 mm/d,降低18.3%。并且倒伏前期日平均降低0.99 mm/d,降低20.6%;倒伏后期日平均降低0.42 mm/d,降低14.8%。更多还原

【Abstract】 【Objective】Strong winds in summer often result in lodging stress to summer maize in central China. The purpose of this paper is to evaluate experimentally how the lodging affects evapotranspiration from a maize field.【Method】The analysis was based on a dataset collected on 25 August 2016 after a strong wind hit Zhengzhou agrometeorological station. Using the Penman-Monteith(P-M) model, meteorological and crop data, as well as vorticity measured in 2017(a normal year), we calculated the evapotranspiration and optimized the model parameters to fit the P-M model to the measured data in 2017. Using the P-M model and the calibrated parameters and field-survey data, we estimated evapotranspiration from the summer maize field without any lodging as the control(P-M_N). The reduced evapotranspiration(P-M_L) due to the lodging in 2016 was estimated using field survey-plant data. 【Result】The evapotranspiration calculated without lodging agreed well with the measured data,with an absolute error of 0.005 mm/30 min, a relative error of 10.7%, and root mean square error and consistency index being 0.019 and 0.98 respectively. For the lodged maize field, the absolute and relative errors between the calculated and measured evapotranspiration were 0.002 mm/30 min and 2.9%, respectively, and the root mean square error and the consistency index were 0.001 and 0.98 respectively. 【Conclusion】Mazie lodging at milk stage due to strong winds significantly reduced its evapotranspiration. Results calculated using the P-M model showed that the lodging reduced daily evapotranspiration by 0.68 mm, a 18.3% reduction compared to the control. The reduced daily average evapotranspiration in the early stage of the lodging was 20.6%(0.99 mm), while in the later stage it decreased to 0.42 mm, 14.8% down compared to the control.更多还原