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- Title
半干旱区周年全膜覆盖对玉米田土壤冻融特性 和水热分布的影响.
- Authors
王红丽; 张绪成; 于显枫; 侯慧芝; 方彦杰; 马一凡
- Abstract
Relying on the three-year field positioning experiment (2015-2017), two processes of annual total film coverage (PM) and bare land (CK) were set up to analyze the relationship between soil temperature and humidity gradients and hydrothermal movement in semi-arid and cold areas. The results show that the freezing and thawing processes of PM and CK are one-way freezing and two-way thawing. Compared with CK, the freezing period of PM lags, the freezing rate slows down, and the freezing depth is shallower by 20 cm, but the melting rate is faster and the melting period is shortened by 6-7 days. During the freezing period, the temperature gradients of PM and CK are both positive, and the heat is transferred to the upper layer of soil, but the intensity of PM conduction is greater than that of CK. During the thawing period, the temperature gradient of PM is positive, and the heat is transferred to the upper layer, while CK is the opposite. The movement of soil moisture is as follows: PM moves upwards throughout the freezing period, and CK shows a "down-up-down" movement; during the melting period, PM moisture moves upwards, and CK moves upwards during the initial melting period. In the middle and late thawing period, it migrates to the lower layer. During the freezing period, the soil temperature gradients of PM and CK are positively correlated with the humidity gradient, but the correlation of PM is greater than CK. The temperature gradient of PM soil during the thawing period is positively correlated with the humidity gradient. Moisture moves to the upper layer at the same time, CK is negatively correlated, and soil heat and moisture move to the lower layer at the same time. Driven by the gradient of soil temperature and humidity, the soil temperatures of PM 0 ~ 10, 10 ~ 20, and 20 ~ 30 cm before fusion-sowing were compared. The average increase of CK is 1.13 ~ 1.34, 0.96 ~ 1.24 and 0.89-1.32%: the soil moisture content is increased by 3.4% ~ 5.6%, 1.4% ~ 2.2% and 6.7% ~ 7.8% respectively. It can be seen that PM can be semi-arid and cold The overwintering crops in the district provide green water and spring sowing crops for seeding, emergence and seedling protection to provide water and heat protection.
- Subjects
SOIL moisture; SOIL temperature; HEAT transfer; WATER springs; THAWING
- Publication
Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao, 2020, Vol 31, Issue 4, p1146
- ISSN
1001-9332
- Publication type
Article
- DOI
10.13287/j.1001-9332.202004.027