不同犁底层深度土壤水热运移过程试验与模拟

Experiment and simulation of soil water and heat transfer process in different depth of plough bottom

为了探索覆膜滴灌条件下犁底层深度对土壤水热运移影响的机理,本文采用土柱试验与模拟相结合的方法,修订了HYDRUS土壤水热运移模型主要参数,对不同犁底层深度(0 cm(CK)、20 cm(PB20)、30 cm(PB30)、40 cm(PB40)、50 cm(PB50))下土壤水热运移规律进行研究。结果表明:模型能够较好模拟不同犁底层深度下土壤水分和温度的分布以及随时间变化的趋势;犁底层可以阻碍水分运移,减缓水分向下的入渗速度,心土层各土层的含水率比耕作层各土层的含水率高,土壤表层的含水率随犁底层深度的增大而增大;PB处理的土壤表层温度比CK处理高2℃左右,随着犁底层位置的加深,耕作层下部土壤温度明显增加。研究结果可为新疆地区作物高产稳产、农业生产可持续发展提供参考。

In order to explore the mechanism of soil water and heat transfer under the condition of mulching drip irrigation, the main parameters of HYDRUS soil water and heat transfer model were revised by the method of soil column test and simulation, and the law of soil water and heat transfer under different plough bottom depths(0 cm(CK),20 cm(PB20),30 cm(PB30),40 cm(PB40),50 cm(PB50)) was studied.The results show that: the model can better simulate the distribution of soil moisture and temperature under different depths of plough bottom and the trend of change with time;the plough bottom can block the water movement and slow down the infiltration rate of water downward;the moisture content of each layer in the subsoil layer is higher than that of each layer in the tillage layer, and the moisture content of the surface layer increases with the increase of the depth of plough bottom;the PB treated soil surface temperature is about 2℃ higher than CK treatment.With the deepening of the bottom position of plough, the soil temperature of plough layer increases obviously.The results can provide reference for the high and stable yield of crops and the sustainable development of agricultural production in Xinjiang.