2002-07-08_GENERAL DOCUMENTS - M2002004 (3)

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SMITH, REDENTE, and HOOPER tal inoculation of revegetation :a fungi has enhanced seedling of revegetation species. Thus, repetitive ability and productiv- 'cation of vesicular - arbuscular is not been demonstrated even ttion methods are in progress. 'loping commercial application mphasize methods of maintain - Drage periods or using direct re- matter level in the plant growth baseline conditions under a to- sed in the post- mining reclama- recommendation is important. surrounding undisturbed areas he rate at which C is lost from :r content increases. Likewise, ,curbed soils may indicate long- 1 abundant supply for reclama- horizon(s) having a greater per - should be stockpiled separately :t topsoil criteria. During over - tion, the first -lift topsoil should in the minesoil profile. ion is the proposed post- mining be about 75 percent of unculti- vated baseline conditions under le, if the pre- mining land use is d use is cultivated cropland, op- rf baseline values. an estimate of what these rule - ty vary with location. Through - :r content ranges from 0.5 to 12 .s of the West, levels are usually nt of the Southwest virgin soil t, whereas organic matter levels 2.5 to 6 percent. Mountainous organic matter levels of 2 to 12 - get levels for organic matter in ve site and soil quality. Organic niting criterion of soil material SOIL ORGANIC MATTER being evaluated for use as topsoil. The following organic matter application and management recommendations can mitigate adverse conditions that may exist in nontopsoiled plant growth media: ► If the major limitation of the plant growth media is a clay, loamy sand or sand texture, or a loamy or sandy skeletal particle size class, at least 2.2 t /ha of organic matter should be incorporated into the upper 8 cm of soil. ► If the major limitation of the plant growth medium is its sodic condi- tion, up to 4.2 t /ha of organic matter could be incorporated into the upper 20 cm of soil to increase infiltration and permeability. This condition will create an environment where, under irrigation or in higher rainfall areas, application of Na replacement amendments, such as CaSO3, will optimize Na cation displacement. ► If the slope of the reclaimed land exceeds 25 percent and annual pre- cipitation exceeds 30 cm, or the area receives intense thunderstorms, 2.2 t /ha or more of organic matter (straw mulch) should be applied, all other soil conditions not limiting, to increase infiltration and minimize water erosion. ► Any area receiving applied organic matter with a C/N ratio exceeding 20:1 may need N fertilization. ► Soil areas to be stripped and then have the topsoil replaced directly should be given consideration for rotoclearing prior to stripping. ► With the possible exception of the northern Great Plains, cropland use of mined land is discouraged for several years after mining because of the organic matter loss and, hence, accelerated erosion that may occur under this form of management. ► Excessive applications (? 200 t /ha) of manure or sewage sludge should be avoided in any type of plant growth media. P. Applications of organic matter will raise the cation exchange capacity of the soil. ► Application of organic matter to nontopsoiled or spoil plant growth medium via the use of a leguminous covercrop should appreciably increase the dynamic fraction and possibly accelerate processes of soil organic formation when moisture is adequate. REFERENCES 209 1. Agricultural Research Service, U.S. Department of Agriculture. 1965. Predicting rainfall- erosion losses from cropland east of the Rocky Mountains. Agricultural Handbook 282. Washington, D.C. 2. Alexander, M. 1977. Introduction to soil microbiology. John Wiley and Sons, Inc., New York, New York. 467 pp. 3. Allen, E. B., and M. F. Allen. 1980. Natural reestablishment of vesicular-arbus- cular mycorrhizae following strip -mine reclamation in Wyoming. Journal of Ap- plied Ecology 17: 139 -147. 4. Allison, F. E. 1973. Soil organic matter and its role in crop production. Developments in soil science, 3. Elsevier Scientific Publishing Company, Amsterdam, The Netherlands. 637 pp.