The Effects of Hay and Straw Mulches on Soil Temperatures and Moisture Values

Abstract

<p> Measurements of soil temperature and soil moisture values beneath and in close proximity to circular mulches of hay and straw were made. The experiments were conducted to determine whether sub-surface effects vary with mulch diameter, and to acquire information concerning the seasonal changes in such effects produced by a mulch of most favourable diameter. The modification of soil climate increased with a greater mulch size. A circular mulch with a diameter of 60 cms or less was considered to be of no practical value for winter protection of roots. The mulch with a 240 cms. diameter, provided some winter protection, preventing freezing of the soil, and, in summer caused considerable modification of the sub-surface climate. In the summer, soil temperatures were lowered by values of up to 5°C and 2.5°C at 5 and 100 cms. depth respectively. After a two-month period of dry weather, moisture values at 0-10 cms. depth beneath the mulch were 20% by volume, whereas, outside the mulch they were 5%. These differences decreased with increasing depth but were over 10% at 100 ems. </p>