Importance of Soil Fertility, Soil Sampling, and Fertilizer Recommendations in the Inland Pacific Northwest

Abstract

Organic debris, including wood residues, provides parent materials for development and function of organic mantles on forest soils. Along with providing a storehouse of nutrients and moisture, organic materials provide either the environment or the energy source for microorganisms critical to both the nutritional quality of forest soils and the ability of conifers to extract nutrients and moisture from the soil. The role and relative importance of specific organic components can vary substantially with site and conifer species. Age of the trees appears to have less of an effect on importance of organic matter than site or species. Of the many organic materials incorporated in a forest soil, the woody component is in many ways the most important. To protect productive potential of forest soils, a continuous supply of organic materials must be provided, parti<?ularly in harsh environments. In case· of excess losses of the organic mantle, complete recovery of the site may require several hundred years, even with proper management.