盐分胁迫条件下制种玉米根系吸水模型参数的推求

The Calculation of the Root Water Uptake Model Parameters of Maize under Salt Stress Conditions

为了研究咸水灌溉条件下作物根系吸水与根区土壤盐分运动的关系,在石羊河流域开展咸水灌溉田间试验,引入Feddes提出的根系吸水模型,根据田间试验实际观测数据,对模型系数进行了计算。研究表明,通过计算相对根长密度和潜在蒸腾速率,推算得到最优灌水条件下的最大根系吸水速率;通过计算蒸腾强度与土壤渗透势,推算得到咸水充分灌溉条件下的盐分胁迫修正因子,并对盐分胁迫修正因子的参数p进行了验证,参数p推算和验证过程时的RMSE<0.10,MRE<10%,在允许的误差范围之内。建立了盐分胁迫条件下制种玉米根系吸水模型,为研究区研究制种玉米生长条件下土壤水盐运动规律奠定基础。

In order to study the relations between the root-water-uptake of crop and salt transport in root zones field experiments are conduc-ted under saline water irrigation in the Shiyanghe River Basin. It is introduced into the root-water-uptake model, which is proposed by Fed-des. The root-water-uptake model coefficients are calculated based on the field experiments and practical observed data. The results show thatthe maximum root-water-uptake rate is calculated under the optimal irrigation conditions by calculating relative root length density and poten-tial transpiration rate. It also calculates salinity stress reduction function under sufficient irrigation with saline water by calculating transpira-tion intensity and soil osmotic potential. The parameter （p） of salinity stress reduction function is validated and compared with calculationvalue. The RMSE values are less than 0.1 and the MRE values are less 10% within the allowable error range in validation and calculation ofthe parameter （p）. It establishes the root-water-uptake model of maize under salinity stress conditions. This model is conducive to under-standing the law of soil water-sah movement under maize growth.