| 摘要: |
| 为研究旱地玉米全膜双垄沟垄体结构对其水热效应的影响程度，采用数值模拟方法对垄体结构和保温保水性能之间的关系进行研究。参考现有的全膜双垄沟种床构建农艺要求建立4种垄体模型，分别为T1、T2、T3和T4模型，对其雨水入渗和热平衡过程进行数值模拟，结合模拟结果对玉米全膜双垄沟垄体结构和相应的配套机具进行了优化。入渗模拟结果表明:在相同降雨边界条件下T2模型垄沟内土壤平均含水率最高(含水率为18.0%)，其次为T4模型(16.9%)。热平衡模拟结果表明:在相同的温度边界条件下T4模型垄沟内土壤平均温度最高(温度值为23.5 ℃)，T2模型最低(22.8 ℃)，兼顾保温性和保水性2个因素，T4模型为最优模型。在T4模型的基础上对现有的全膜双垄沟垄体结构进行优化，优化后的垄体呈拱型结构，大垄拱顶弧半径为48 cm，大垄宽70 cm，垄高15 cm；小垄拱顶弧半径为22 cm，小垄宽40 cm，垄高20 cm；垄沟为梯形结构，沟底宽8~10 cm，沟底与大垄宽度比约1∶7，与小垄宽度比约1∶4。同时配套的起垄铺膜机具需要安装垄体整形装置，其形状和结构要与优化后的垄体相匹配，配套的直插式穴播机行走轮宽度应小于垄沟沟底宽度(8~10 cm)，播种后膜孔半径保持在4~5 cm。 |
| 关键词: 全膜双垄沟 水热效应 数值模拟 农艺优化 |
| DOI：10.11841/j.issn.1007-4333.2020.01.03 |
| 投稿时间：2019-04-08 |
| 基金项目:国家自然科学基金项目(51775115、51405086)；农业部西北农业装备重点实验室开放基金(2017NAE-01) |
|
| Agronomic optimization of maize whole plastic-film mulching on double ridges of maize in arid land based on numerical simulation study on moisture and thermal effect |
|
WEI Wancheng,DAI Fei,ZHANG Fengwei,ZHANG Shilin,SHI Ruijie,LIU Yuanxiang,SHEN Pengyun
|
| (College of Mechanical and Electrical Engineering, Gansu Agricultural University, Lanzhou 730070, China) |
| Abstract: |
| To study the moisture and thermal effect of the whole plastic film mulching on double ridges of maize in arid land, the relationships between the structure of the ridges and the thermal insulation and water retention performance are studied by numerical simulation method. Four kinds of ridge models, namely T1, T2, T3 and T4 model, are established referring to seedbed construction agronomic requirements of whole plastic-film mulching on double ridges. The process of rainwater infiltration and thermal equilibrium is numerically simulated. Combined with the simulation results, the structure of ridges of the whole plastic film mulching on double ridges and the corresponding supporting machine are optimized. The results of rainwater simulation showed that: Under the same rainfall boundary conditions, the average water content in the T2 model is the highest(water content is 18. 0%), followed by the T4 model(16. 9%), which showed that the ridge structure of T2 model has the best water retention performance. The results of thermal equilibrium simulation showed that under the same temperature boundary condition, the average soil temperature in T4 model is the highest(temperature value is 23. 5 ℃)and the T2 model is the lowest(22. 8 ℃), which showed that the structure of ridge of T4 model has the best thermal insulation performance. However, considering the thermal insulation and water retention, T4 model is the optimal model. In conclusion, The existing structure of the ridge is optimized base on the T4 model: The structure of the ridge arch should be arched, the radius of the large ridge arch is 48 cm, the width is 70 cm and the height is 15 cm, the radius of the small ridge arch is 22 cm, the width is 40 cm and the height is 20 cm; The furrow is trapezoidal, the bottom width is 8-10 cm, and the trench width ratio with large furrow is about 1∶7, the trench width ratio with small furrow is about 1∶4; At the same time, the ridging and spreading machines need to be fitted with a ridge shaping device, and its shape and structural parameters should be matched with the optimized ridge, the width of the walking wheel of the matching direct insert hill-seeder should be less than the width of the furrow(8-10 cm), and the radius of the membrane hole remains at 4-5 cm after sowing. |
| Key words: whole plastic film mulching on double ridges moisture and thermal effect numerical simulation agronomic optimization |
