Objective  Mulching soil will affect the distribution of soil water and heat. Studying the influence of different mulching methods on the distribution of soil water and heat can provide a reference for the selecting of appropriate mulching methods for different crops to control the distribution of soil water and heat.

  Method  In order to explore the effects of different mulching methods on the distribution of soil water and heat, field experiments with 5 experimental treatments of no coverage, plastic film coverage, 1.5 cm deciduous coverage, 3 cm deciduous coverage and 4.5 cm deciduous coverage, were conducted to determine the temperature, moisture content and evaporation of soil planted with corn seedlings under different mulching methods.

  Result  For the same mulching time, the 5 cm soil layer under the mulching film had a large daily temperature difference in summer, with a dramatical temperature variation. The soil temperature difference under the deciduous mulching was small with a gentle temperature variation. Plastic film mulch increased the summer temperature of the 5 cm soil layer, while the leaf mulch reduced the soil temperature. The thicker the leaf mulch, the more significant effect. Mulching soil improved the water retention of the soil. The moisture content of the 5 cm soil layer under the leaf mulch showed an increasing trend. Compared with no mulching, the soil water evaporation under the treatments of plastic mulch, 1.5 cm, 3 cm and 4.5 cm deciduous mulches decreased by 43.61%, 25.03%, 27.19% and 30.96%, respectively. The change law of cumulative soil moisture evaporation over time under different mulching methods could be characterized by an exponential equation.

  Conclusion  For farmland soil, plastic mulch increased temperature and saved water, while deciduous mulch reduced temperature and saved water. The thicker the leaf mulch, the more significant effect.