Tree Nutrition and Soil Fertility

Investigations at the Wareham Forest have shown that the presence of a soil toxin tends to prevent both the production of short roots in Scotch pine seedlings and the subsequent conversion of these roots into mycorrhizae. Under field conditions the activity of the toxin-producing organisms can be suppressed, and the development of mycorrhizae stimulated, by mixing with the soil various composts, which thereby produce conditions favorable to the vigorous growth of the seedlings. The judicious application of suitable composts helps to hasten the successional changes in soil microorganisms which normally accompany successional changes in surface vegetation in the transformation of grassland to woodland, and thus make it physiologically possible for trees to be planted successfully on such areas sooner than would otherwise be the case.