Effect of farmland microclimate irrigation

After irrigation, the ground reflectivity decreases, the solar radiation income increases, and the evaporation heat consumption on the soil surface is strong, thus weakening the temperature gradient and turbulent exchange between the air layer and the soil layer. At the same time, with the increase of soil water content, soil heat capacity and thermal conductivity increase, while soil heat flux decreases significantly, and daily temperature difference also decreases. Therefore, irrigation in daytime and warm season can produce cooling effect; At night and in the cold season, it can produce the effect of heating. The temperature effect of irrigation is more obvious during the day in warm season and more obvious at night in cold season. Irrigated farmland may also have inversion during the day. Irrigation effect is not only influenced by region, season, day and night, weather conditions, but also has a great relationship with irrigation methods, irrigation area, irrigation amount and soil conditions. Generally, the larger the irrigation area, the looser the soil, the lighter the soil color, and the clearer and drier the weather conditions, the more obvious the effect will be. The temperature effect of irrigation is also restricted by the irrigation water temperature. In production, the temperature of farmland can be adjusted according to the change of water source temperature.