The Effect of Mulches on Soil Temperature
A mulch is a blanket put over the soil surface to control weeds, reduce fluctuations in soil moisture, modify soil temperature, avoid damage from splashing of soil or even to reduce insect infestation on crops. The effects of various mulch materials on control of weeds and insects have been covered in other writings. In this article we will dis cuss some of the effects of mulch materials on soil temperature. There is a great variety of mulch materials that can be used as a layer over the soil surface. Inorganic granular materials would include stones, sand and calcined clay pellets. Organic granular or fibrous materials would include peat moss, chopped bark, cocoa hulls, peanut hulls, licorice root, woodchips, grass clippings, hay, etc. Mulch mats could be of fiberglass or organic fibers. A mulch could also be sheets of paper, paper covered with plastic or aluminum foil, clear polyethylene or polyvinyl film or film impregnated with a black opaque material or covered with a reflective surface. There is no limit to the kinds of materials that could be used as a mulch, but horticulturalists are only interested in those that produce benefcial effects, are relatively easy to apply, are easy to obtain in large quantities and are inexpensive. In cold weather the soil cools off at night by loss of heat to the cold air and radiation to the cold sky. It warms up in the daytime. If air temperatures are below freezing the surface freezes, but depth of freezing is limited by the warmth from non-frozensoil below and the heat given off in freezing as well as by air temperature. Soil temperature changes are most rapid at the soil surface and decreases with depth.
Source: • New York State Flower Industries, Inc. Bulletin #25
Keywords: Soil temperature Freezing control weed Insect infestation loss of heat