HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Li, R. S. Articles by Daniels, W. L. Search for Related Content PubMed Articles by Li, R. S. Articles by Daniels, W. L. Agricola Articles by Li, R. S. Articles by Daniels, W. L.

Nitrogen Accumulation and Form over Time in Young Mine Soils

Dep. of Crop and Soil Environ. Sci., Virginia Polytechnic Inst. and State Univ., Blacksburg, VA 24061-0404.

^* Corresponding author.

ABSTRACT

Nitrogen deficiency is a common problem during reclamation of mine soils, and limited comprehensive information is available concerning the forms and characteristics of N in Appalachian mine soils. This chronosequence study was conducted to investigate the accumulation, distribution, and component change of N in mine soils over time. Fresh spoil, coal, natural forest soil and 10 mine soil sites with ages ranging from 1 to 30 yr were sampled and analyzed for N components. Young mine soils (> 10 yr) were dominated by seeded grass-legume vegetation, while the older sites supported native mixed hardwoods. There was a considerable amount of indigenous N in the fresh spoils (250–475 mg kg^–1), consisting primarily of fixed NH⁺₄ (Fix-N) held in micas and nonhydrolyzable organic N (NoHyOM-N) bound in coal. Both the Fix-N and NoHyOM-N fractions were geologic N, stable in chemical character, and unavailable to plants. With time, N accumulation occurred primarily in the surface 0 to 5 cm, associated with A horizon development. In this layer, soil total N and active N [Act-N, consisting of hydrolyzable organic N (HyOM-N) and exchangeable N (Exch-N)], were significantly correlated with site age. The corrected-N (Corr-N), which was obtained by subtraction of soil total N at 10 to 20 cm from soil total N at 0 to 5 cm at each site, had a much higher correlation coefficient with site age (r = 0.95, P < 0.0001) due to its correction for variation in soil indigenous N content among sites. The annual rate of N accumulation estimated by the Corr-N method was 60.5 mg N kg^–1 in soil (<2mm) or 23.4 kg N ha^–1 in the top 0 to 5 cm. The total C content of the mine soils was correlated with site age (r = 0.65, P < 0.05), while pH, N availability index, Fix-N, and NoHyOM-N were not.