Observations on the reduction of soil temperature

✍ Scribed by G. Stanhill

• Publisher: Elsevier Science
• Year: 1965
• Weight: 348 KB
• Volume: 2
• Category: Article
• ISSN: 0002-1571
• DOI: 10.1016/0002-1571(65)90018-x

✦ Synopsis

In some of the vegetable growing areas of Israel the soil temperature during the day at sowing depth is above the average optimum for vegetable crop germination from the beginning of June until mid-September. During July the temperature equals the average maximum for germination.

Surface dressings of a commercial grade of magnesium carbonate were applied in an attempt to reduce the temperatues. These maximum soil temperatures were reduced by some 10°C for approximately three weeks after treatment. Doubling the rate of application did not increase the effect, but it was maintained for a longer period.

Measurements showed that the radiation balance on the treated surfaces was only one sixth of that on the control surface, mainly because the application of magnesium carbonate doubled the albedo of the soil surface. The treatment reduced the evaporative heat flux by one fifth and reversed the direction of the convective-heat flUX, Except in the period immediately following application, the soil heat flux was not greatly affected by the surface treatment.