The efficiency that black mulch increases soil temperature, that is, transfers heat from the mulch to the soil, can be improved by optimizing contact between the mulch and the soil surface.

• 黑色塑料薄膜提高土壤温度的效率（即把热能从薄膜传递到土壤）可以通过使薄膜与土表最适的接触来提高。