How to regulate soil temperature in greenhouses? A detailed guide to practical methods

1. High-ridge cultivation with plastic film mulching. Growing crops on high ridges in greenhouses and polytunnels increases the soil surface area, which helps the soil absorb more heat and raises soil temperature. Mulching with plastic film can raise soil temperature by 1°C-3°C and also increases the light reaching the area near the ground.

2. Dig cold-proof trenches. To reduce the exchange of soil heat between inside and outside, a cold-proof trench should be dug along the front edge of the greenhouse. The depth of the cold-proof trench should equal the thickness of the local frozen soil layer, and the width should be half the thickness of the frozen soil layer. Fill it with insulating materials such as weeds and horse manure, then cover it with plastic film and soil.

3. Apply more organic fertilizer in greenhouses and polytunnels. The biological heat released when these organic fertilizers decompose can raise soil temperature. At the same time, increasing soil organic matter can also improve the soil's ability to absorb and retain heat.

4. Maintain soil moisture. Soil with a high water content appears dark in color, which can improve the soil's heat absorption capacity. The high heat capacity of water can also increase the soil's heat preservation capacity.

5. Put up the greenhouse covering earlier. For large greenhouses and small and medium-sized tunnels, put up the frame and cover with film earlier to increase the amount of heat stored in the soil.

6. Underground heating. Using equipment such as electric heating cables, hotbed fermentation materials, and underground hot water pipe channels to heat the soil is the most effective measure for raising soil temperature, but the cost is relatively high.

7. Cooling. When soil temperature is too high in spring, in addition to lowering soil temperature by lowering the air temperature, you can also water in the evening to lower soil temperature. Xu Yongmei