耕作及种植方式对土壤入渗参数和畦灌水流运动的影响

Effects of tillage and planting patterns on soil infiltration parameters and water flow of border irrigation

为探明耕作和种植方式对土壤入渗参数及畦灌水流运动的影响规律,试验设置了4个处理(深松+旋耕+等行距、深松+旋耕+三密一稀、旋耕+等行距、旋耕+三密一稀旋耕+三密一稀),每个处理中设3种不同畦田规格(畦长30、35、40m,畦宽均为2m),越冬和拔节期分别进行灌水,实测了入渗量、水深、水流推进时间等,基于采用Kostiakov入渗公式计算的土壤入渗参数和WinSRFR4.1软件优化法求解的入渗参数,研究不同处理下入渗参数变异对畦灌水流运动的影响。结果表明:1)田间试验实测值和基于WinSRFR4.1软件优化模拟值间入渗系数和入渗指数相对误差最大值分别为1.24%和1.57%,表明采用2种方法确定不同耕作和种植方式下土壤参数均可行;2)耕作和种植方式的不同会对土壤入渗参数产生较大影响,前者影响更大。3)越冬期和拔节期灌水时入渗系数变异系数最高分别为0.34和0.22,入渗指数变异系数最高分别为0.14和0.13。2次灌水期间相同处理入渗参数也发生了时间变异性,处理深松+旋耕+等行距和深松+旋耕+三密一稀的入渗系数和入渗指数均发生中等变异性,处理旋耕+等行距和旋耕+三密一稀发生弱变异性。4)在土壤入渗参数的变异性影响下,2次灌水过程中,不同处理水流运动时间均发生了变异性。5)基于土壤入渗参数变异性,确定了2次灌水不同耕作及种植方式冬小麦畦灌条件下土壤入渗系数和入渗指数。研究结果可为畦灌系统设计和管理评价提供理论依据和技术支撑。

It is important to understand infiltration characteristics of irrigation water in soils under different tillage and planting pattern conditions. In this study, we studied the effects of tillage and planting patterns on soil infiltration parameters and flow movement of border irrigation. A total of 4 treatments were designed. They were subsoiling and rotary tillage with planting mode of equal line spacing(15 cm)(I), same with I in tillage method but different in planting mode with line spacing of 12.5 cm+12.5 cm+15 cm(II), same with I except that subsoiling is not used(III) and same with III except that the planting mode is line spacing of 12.5 cm+12.5 cm+15 cm(IV). The treatment of I and II had the same tillage method but different planting pattern and the treatment of I and III had the same planting pattern but different tillage method. A total of 3 plots with different lengths(30 m, 35 m and 40 m) and same width(2 m) were prepared for each treatment. The calculated values of infiltration parameters were obtained by Kostiakov model. Meanwhile, WinSRFR4.1 software optimization method was used to obtain the simulated values of infiltration parameters. Then, the effect of infiltration parameters variability on water movement was analyzed. The results showed that: 1) the maximum relative errors of infiltration coefficient and infiltration index between the calculated value and the simulated value by the software were 1.24% and 1.57%, respectively. It indicated that it was feasible to simulate the soil infiltration parameters under different tillage and planting patterns by the software. 2) The tillage and planting method had effects on soil infiltration parameters. Compared to the planting pattern, the tillage had the much more influence on the infiltration parameters. 3) Coefficients of variation of infiltration coefficient were up to 0.34 and 0.22 at the wintering and jointing stage, respectively. In these 2 stages, the coefficients of variation of infiltration index reached 0.14 and 0.13, respectively. The infiltration parameters showed a time-dependent change trend. The infiltration coefficient under the subsoiling plus rotary tillage condition had the medium variability while the infiltration index of the rotary tillage had the weak variability. 4) Affected by the influence of variability of infiltration parameters, the irrigation water movement was also variable depending on the time. The variability of water movement during the second irrigation period was weaker than that during the first irrigation period. 5) Based on the variability of soil infiltration parameters, infiltration parameters in the 2 irrigation periods were determined in the different tillage and planting pattern. The result proposed in this study could better provide technical support for the design and management evaluation of border irrigation system.