Salty bark as a soil amendment

Abstract

Bark from Douglas-fir logs floated in sea water contained 0.75 to 1.94 percent salt (NaCl). Leaching by natural and simulated rainfall and by soaking readily removed this salt. Bush bean and tomato plants were grown in the greenhouse on a sandy loam soil to which bark of three different proportions of salt was applied as a mulch and as an incorporation at the rate of 40 tons per acre. Mulches containing 0.75 and 1.41 percent salt had little effect on beans but bark containing 1.94 percent salt was slightly depressive; all the incorporations were depressive. Tomato plant yields were reduced by all the bark treatments, most severely by the incorporations. Use of salty bark at usual rates on the soil can injure salt sensitive plants. Mulches would be less hazardous than incorporations. Chunk sizes would probably cause no toxic effects. Most soil microbes and their essential activities are not likely to be appreciably influenced by salt leached into the soil from salty bark.

Citation

Bollen, W.B. 1971. Salty bark as a soil amendment. Res. Pap. PNW-RP-128. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 20 p