EVALUATION OF SOIL-TEMPERATURE MODERATING AND MOISTURE CONSERVING EFFECTS OF VARIOUS MULCHES DURING A GROWING-SEASON

The seven mulches investigated affected soil temperature throughout th e season compared with bare soil. The degree of temperature moderation varied depending on whether the temperature trend was increasing, rel atively constant or decreasing. The organic mulches, wood chips and si lage, as well as spun polypropylene covered with wood chips kept the s oil temperature cooler compared with bare soil until middle of August. During periods of soil warming, spun polypropylene and paper reduced soil temperature. Soil under black plastic had a higher mean temperatu re than bare soil throughout the season. Degradable plastic increased soil temperature, but only to a small extent. The organic mulches cons erved more moisture than any other of the materials evaluated, althoug h during July soil moisture contents were significantly higher under a ll mulches compared with bare soil.