Fertilizer and Organic Amendment Effects on Mine Soil Properties and Revegetation Success
- Stephen H. Schoenholtz ,
- James A. Burger and
- Richard E. Kreh
Nitrogen deficiency frequently limits mine-soil revegetation in the eastern USA. Application of organic amendments to these systems may provide a long-term source of N and eliminate the need for repeated fertilization. A factorial experiment was conducted using lysimeters to determine the degree to which (i) organic amendments (control, 50 Mg ha−1 of whole-tree wood chips, or 500 Mg ha−1 of native topsoil) and (ii) inorganic N fertilizer (0 or 100 kg N ha−1 as NH4NO3) affected mine-soil properties and establishment of herbaceous vegetation and pitch × loblolly hybrid pine (Pinus rigida L. × P. taeda L.) seedlings on a newly exposed mine soil from the central Appalachian region. Amendments were tilled into the soil surface prior to application of fertilizer and cover-crop seed. After 3 yr, total N, mineralizable N, and organic C in the wood-chip-amended mine soil were 10, 50, and 18% higher, respectively, than the control. Tree growth after 2 yr was highest with wood chips. A lack of wood-chip treatment effect on pine nutrition showed that higher soil moisture levels, resulting from lower evapotranspiration, probably accounted for improved tree growth. Topsoil replacement increased total N and mineralizable N by 23 and 46%, respectively, but did not significantly increase vegetation productivity over that of the control. Nitrogen fertilizer increased herbaceous biomass production by 87% during the first growing season but did not affect herbaceous or pine productivity in two subsequent years or produce lasting effects on soil nutrient levels. Organic amendment × fertilizer interactions were not significant for any measured parameters. Results show that the organic amendments provided more stable sources of soil N; however, early revegetation success was more a function of moisture than of soil nutrient availability.
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