Abstract. The objective of the current study was to determine the effect of different mulches, lime and fertilizer applications on the establishment and growth of vegetation on two surface mine sites in western Pennsylvania. One site was reclaimed under the current regulations (1977) while the second site was mined and reclaimed prior to the passage of PL 95-87. Experimental quadrats were established in a checkerboard manner and all but one quadrat, which served as a control, received either mulch, lime and/or fertilizer alone or in combinations of mulch, lime and/or fertilizer. Quadrats were seeded with either annual rye (Lolium multiform), winter wheat (Triticum aestivum), K-31 fescue (Fescue aurndinacea),_ alfalfa (Medicago sativa) or buckwheat (Fagopyrum sagittatum). Generally, those quadrats that were mulched with either straw or bark enhanced the establishment of vegetation to a greater degree than newsprint, which in some cases was detrimental, when compared to the control. However, considerable variation existed among the different species in their response to mulch and/or lime fertilizer applications. Generally the response of vegetation to all treatments was better on the site with top soil replacement than it was on the older site which was reclaimed in the early 1960's.
Additional key words: Mulch, Lime, Fertilizer, Establishment, Growth, and Biomass of Winter Wheat, Annual Rye, Fescue, Alfalfa, Buckwheat.
1 Paper presented at the 1990 Mining and Reclamation Conference and Exhibition, Charleston, West Virginia, April 23-26,1990.
2 Fred J. Brenner is a Professor of Biology Grove City College, Grove City, PA 1612?.
The application of mulch, lime and fertilizer has been a standard practice in reclaiming mine lands for over two decades. Previous studies have shown that mulching will enhance the establishment and growth of vegetation on disturbed lands (Dyer et al. 1984). These authors found that bark was slightly superior to hay as a mulch but that no single mulch was best for all soil types. These authors further indicated that considerable variability existed in the response of vegetation to different mulches and that some mulches could have an adverse effect on vegetation. In general, the use of mulches which are high in organic matter, such as bark chips, hay and straw, were better for the establishment of legumes than for grasses. In the southwest, Flkins et al. (1983) found that bark as an organic amendment to minesoils was as effective in developing a productive soil profile as the more expensive applications of topsoil and mulch currently recommended for surface mine reclamation.
Lime and fertilizer applications prior to seeding is a common practice in re-vegetating mined lands. DePuit and Conenbert (1979) found that a light fertilizer application may be best to enhance species diversity while prolonged fertilizer applications will increase biomass production. However, fertilizer applications at maintenance levels had little long-term impact on soil fertility. In another study, Hanson et al.(1982) found that lime application increased yield for one year but not the following year and that there was not a significant difference between sites receiving lime applications and those which did not. McFee et al. (1981) found that the application of 10-10-10 fertilizer improved the growth of both wheat and alfalfa on all types of overburden except black and gray shales. It appears there-fore, that lime fertilizer applications may be important for the initial establishment of vegetation but may not be important in maintaining long-term fertility and biomass production unless fertilizer application is continued on an annual basis.
Experimental 3m2 quadrats were established in a 4x4 checkerboard design on two mine sites (3 replicas per site) located in the glaciated plateau providence of northwestern Pennsylvania. The overburden overlaying the Brookeville coal of the Clarion Formation consisted of glacial till along with shale and sandstone directly above the coal seam. The glacially derived soils on both sites had a pH between 6.0 and 6.6 and the organic content between 3.0% and 4.8% with a moisture content at saturation between 15 and 22%.
The first site, hereafter referred to as site one, was mined after the passage of PL 95-87, whereas the second site, hereafter referred to as site two, was mined in the early 1960's.
All quadrats were established at the same time and were located on a level contour. A wood frame buried at a depth of 15cm separated the individual quadrats. Quadrats, which served as controls, received no treatment while the others were mulched at a rate equivalent to 3 tons/acre of either straw, bark or newsprint as mulch alone, or received various combinations of lime, fertilizer or lime and fertilizer in addition to mulching. The quadrats were limed at a rate equivalent to 2 tons/acre and 10-20-20 fertilizer applications were equivalent to 200 lb/acre as recommended by the Pennsylvania State Agronomy Guide (1987-88).
Quadrats were seeded with either annual rye (Lolium multiforum) , winter wheat (Triticum aestivum), K-31 fescue (Fescue aurndinacea) and alfalfa (Medicago sativa or buckwheat (Fagopyrum sagittatum ).Winter wheat was seeded in September and all other seedlings were completed prior to 31 May. The seeding rates were based on pounds of live seeds/acre (PLS/A) as recommended in the Pennsylvania State Agronomy Guide (1987-88) for seeding on disturbed lands and establishing foliage and small grains (Table 1). All quadrats were seeded with a cyclone seeder to insure as uniform a seeding as possible.
At the end of the first growing season, the number of stems and height of all individual plants on each quadrant was determined for winter wheat, annual rye and buckwheat and the number of stems, height and the plant and root biomass/m2 was also determined for buckwheat. After the second growing season, the biomass, chlorophyll a and plant height and root length of K-31 fescue and alfalfa was determined on each quadrat. The amount of chlorophyll a was also determined according to the procedures described by Richards and Thompson (1952), Parson and Strickland (1963), and Brenner et al. (1975). Chlorophyll a has been used as a factor in Determining the importance of different species occurring on reclaimed mine lands by Brenner et al. (1975) and, thus, was used as another index of the effect of different treatments on the establishment and growth of vegetation on the different quadrats. In addition to measuring the vegetation, a soil sample was obtained from each quadrat to determine the effect of the different treatments on organic matter and moisture on pH. Since these parameters have been shown to be important in the establishment of vegetation on mined lands (Brenner et al. 1984).
Considerable variation existed among the different treatments in both soil characteristics as well as in the response of vegetation. The use of mulch had no significant effect on the amount of organic matter or the moisture content of the surface mine spoil, either among treatments or between the two mine sites as indicated by a two-way analysis of variants (P> 0.75).
Variation also existed among the different species of vegetation in their response to the application of the various mulches and lime-fertilizer treatments between the two mine sites. For example, with winter wheat, the number of plants per m2 on the first mine site was greater when straw was used as a mulch than it was when quadrats were mulched with either bark or newsprint. However, on site two the number of plants/m2 to a greater extent on site one than they did on site two. On site one, the greatest number of plants occurred when straw was used in combination with fertilizer, but there was no a significant difference in the numbers of plants/m2 between the use of fertilizer and the use of lime-fertilizer (P > 0.50). However, when bark was used as a mulch, the number of plants/m2 was greater when lime-fertilizer was used, but there was not a significant difference (P > 0.50) between no lime fertilizer application and when fertilizer was used (Table 2). On the two except for newsprint, the number of plants/m2 was greater on the control quadrat and on those receiving mulch than it was among the different lime and fertilizer treatments.
In contrast to winter wheat annual rye had a better response at site two to all treatment categories with the possible exception of when newsprint was used as a mulch. On site two, the greatest number of plants/m2 occurred when no treatment was used. The greatest number of plants/m2 among different treatments occurred when either straw or bark was used as a mulch in combination with lime (Table 2). When both lime and fertilizer or fertilizer alone was used, the number of plants/m2 increased when straw was used as a mulch, but not on quadrats mulched with bark or newsprint. On one site, the number of plants/m2 were greater when straw was used as a mulch in combination with lime and fertilizer, with the exception of the control quadrats or when newsprint was used as a mulch. On quadrats mulched with straw or bark, the number of plants/m2 varied among the different treatments.
On mine site one, the use of straw along with the combinations of lime and fertilizer increased the growth of both winter wheat and rye compared to the control quadrats. But when bark was used as a mulch, winter wheat showed" a greater growth response than annual rye. On site two, the use of straw with the addition of either 'Lime or fertilizer resulted in a greater increase in the plant growth than when bark was used as a mulch. The least amount of growth on both sites occurred on quadrats mulched with newsprint, regardless of whether fertilizer or lime were applied to the site (Table 2).
K-31 fescue exhibited considerable variation among the different treatments both within and between the two mine sites. On site one, the greatest root biomass occurred on quadrats which were not mulched but received applications of lime and fertilizer, while the greatest above-ground biomass with the smallest root biomass occurred when the quadrats receiving straw along (Table 3). There was considerable variation in the height and biomass of vegetation among the other mulches as well as between treatments with lime and fertilizer (Table 3). The tallest plants occurred on quadrats mulched with newsprint in conjunction with lime, but considerable variation occurred among the other treatments. On site two, the greatest above-ground biomass occurred when bark alone was used as mulch, but the greatest root biomass occurred when bark was used in conjunction with lime and fertilizer. Overall, there was no significant difference in the height and among the biomass of vegetation different mulches or lime and fertilizer applications a indicated by a two-way analysis of variance (P > 0.50).
As with K-31 fescue, alfalfa also showed a considerable variation among the different treatment but there was not as great a difference between the two sites as occurred with K-31 fescue or winter wheat and annual rye. In terms of bio-mass, site one had a slightly greater bio-mass per m2 among the different treatments than site two (Table 4). Overall, on site one quadrats with mulch had a greater bio-mass m2 than the control quadrats, with the possible exception of the control quadrats that received lime and fertilizer applications but differences occurred in the amount of above-ground and root biomass on site one among the different treatments (Table 4). On site two plant and root length, was greatest on the quadrats that received bark mulch without lime and fertilizer and there was not a significant difference among the other treatments in either the plant height or root length. Also on site two, the greatest biomass occurred on the control quadrats receiving the lime applications (Table 4). Generally the plants obtained their greatest height and biomass/m2 when bark and newsprint were used as a mulch rather than straw.
As with biomass /m2 and plant height, the mg chlorophyll a kg varied among the different treatments on the two sites. In general, amen the different treatments the chlorophyll a~kg was greater in fescue than it was in alfalfa. On site one, the greatest concentrations of chlorophyll a occurred in fescue on the quadrats mulched with bark or newsprint along with receiving lime and fertilizer application (P> 0.50). As with site one, the greatest concentration of chlorophyll a occurred in plants on the control quadrat receiving lime and fertilizer applications (Table 3,4).
The number of buckwheat plants/m2 on both sites tended to be greater on quadrats mulched with straw or bark than it was on the control quadrat or those mulched with newsprint (Table 5). In regards to the effects of lime and fertilizer treatments on the number of plants/m2 were significantly greater on quadrats receiving straw along or straw and lime that it was on the other quadrats (P > 0.05). However, there was not a significant difference in the number of plants/m2 on the quadrats mulched with draw and those mulched with straw along with applications of lime and fertilizer (P >0.50). When bark was used as a mulch, the number of plants/m2 was essentially the same between the quadrats receiving fertilizer applications and those receiving no additional treatments. on site two, quadrats receiving straw and bark with no addition of lime and fertilizer had a greater number of plants/m2 than those receiving various combinations of lime and fertilizer. Generally, the number of plants/m2 on those plots mulched with newsprint did not differ significantly from the control quadrats (P> 0.50).
On site one, the greatest total biomass of buckwheat occurred on quadrats mulched with straw or bark in combination with either lime or fertilizer. While on site two, the greatest total bio-mass of buckwheat occurred when bark alone was used as a treatment followed by quadrats mulched with bark along with lime and fertilizer. Overall, on site one, there was not a significant difference among the various treatments (P > 0.50). However, those quadrats receiving mulch and/or lime-fertilizer application tended to have a greater biomass/m2 than those that received only mulch (Table 5). On site two, the tendency vas for the greatest biomass /m2 to occur on those quadrats mulched with newsprint. The tallest plants occurred on quadrats receiving lime and fertilizer applications but differences occurred among quadrats receiving different treatments.
As in previous studies, considerable variation existed in the response of the vegetation to the various treatments. Overall, straw and bark appeared to stimulate both the establishment and growth of vegetation on surface mine lands but the response varied among the different species. Likewise, the addition of lime and fertilizer either with or without the use of mulch tended to enhance the establishment and growth of vegetation, but variations also occurred with all species tested. In some instances, the growth was equal to or greater on the control plots which did not receive any additional treatment. In general, with all species tested, the response of vegetation among the various treatments was greater on site one which was reclaimed in accordance with the PL 95-87 regulations as to the placement of top soil-than it was on the older mine site which was mined in the early 1960's.
I would like to thank the Mercer County Conservation District for their assistance both financially and with personnel during the course of the study. I would also like to than Mr. Richard H. Crowley, retired District Conservationist, U.S.D.A. Soil Conservation Service, for his helpful suggestions during the study.
Brenner, F.J., R.H. Crowley, M.J. Musaus and J.H. Goth. 1975. Evaluation and recommendations of stripmine reclamation procedures for maximum sediment-erosion control and wildlife potential. PP. 3-23. Third Symposium Surface Mining and Reclamation. Louisville, KY.
Brenner, F.J., M.W. Werner, and J. Pike. 1984. Ecosystem development and natural succession in surface coal mine reclamation. Minerals and the Environment 6: 10-22.
DePuit, E.J. and J.G. Conenberg. 1979. Responses of revegetated coal strip mine spoils to variable fertilization rates, longevity of fertilization programs and season seeding. Research Report 150. Montana Agricultural Experiment Station. Montana State University, Bozeman, Mont. 75P.
Dyer, K.L., W.R. Curtis, and J.T. Crews. 1984. Response of vegetation to various mulches used in Surface mine reclamation in Alabama and Kentucky-7 year case history. Gen. Tech. Report NE 93. U.S. Depart. Agric. Forest Service, N.E. Exp. Station. 11p.
Elkins, N.Z., L.W. Parker, E. Aldon, and W.G. Whitford. 1983. Responses of soil biota to organic amendments in strip mine spoil, in northwestern New Mexico. J. Environ. Qual. 13:215-219.
Hanson, R.G., M. Tucker, A.D. Cable, and D.A. Steper. 1982. Yield, quality and K/(Ca - Mg) ratio of tall fescue breeding lines on amended and non-amended mine soil. Commun. in Soil Sci. Plant/Anal. 13: 1081-1094.
McFee, W.W., W.R. Byrnes, and J.G. Stockton. 1981. Characteristic of coal mine overburden important in plant growth. J. Environ. Qual. 10: 300-308.
Parsons, J.R. and J.D.H. Strickland. 1963. Discussions of spectrophotometric determinations of marine plant pigments with equations for ascertaining chlorophylls and carotoids. J. Mar. Res. 21: 155-163.
Richards, R.A. and T.G. Thompson. 1952. The estimation and characterization of plankton community by pigment analysis II. A spectrophotometric method for estimation of plankton pigments. J. Mar. Res. 11: 156-172.
The Penn State Agronomy Guide. 1987-1988. The Pennsylvania State University. College of Agriculture Extension Service. Univ. Park. PA 148 p.