Several years ago the Ohio State University Research 

 Foundation (1971) pointed out three methods for 

 abatement of acid production at its source: development 

 of an oxygen barrier on the surface; development of 

 chemical or biological control over the rate of pyrite 

 oxidation; and prevention of the infiltration of water into 

 disposal piles, inactive tailings ponds, and similar 

 sources of production of acid. 



An artificial covering, both waterproof and airproof, 

 would stop the production of acid, but it would be difficult 

 to install and maintain. Also, the cover probably would be 

 feasible for temporary abatement only on comparatively 

 small areas. A natural vegetative cover such as grass 

 would be an alternative. A natural cover would be 

 satisfactory both environmentally and esthetically, and 

 presumably would be permanent and self-sustaining. 

 Such a cover has been demonstrated to be a strong 

 deterrent to overland flow and to soil surface erosion. It 

 also functions as a oxygen barrier. Even if oxygen 

 penetrated the root zone and the pyrites were eventually 

 oxidized, no new pyrites would be exposed if the plant 

 cover could be maintained. 



The above suggest that the logical approach to the 

 Blackbird Mine problem would be to establish a 

 permanent vegetative cover over the waste piles. The 

 Blackbird Mine, however, presents an especially difficult 

 problem. Not only is the spoil material in the waste dump 

 subject to severe acid problems, but the whole dump is 

 located in steep, mountainous terrain that increases the 

 difficulty of establishing a protective vegetative cover. 



east-facing aspect on the waste dump at the head ot 

 Meadow Creek. This experimental block contains 24 test 

 plots, each of which has an area of 1/40 acre (0.01 ha); 

 the total test area occupies approximately 3/5 acre (1/4 

 ha). 



TREATMENTS 



The study area was limed with a lime spreader at the 

 rate of 900 lb/acre (1 009 kg/ha), the requirement as 

 calculated by a university laboratory using a modified 

 SMP buffer method (Shoemaker and others 1961). The 

 lime was then harrowed into the ground by a Triple-K 1 

 harrow to a depth of about 8 inches (20.3 cm). 



On 1 2 of the 24 test plots, hay was used as soil organic 

 amendment by being worked into the surface 10 inches 

 by a Howard rotovator at the rate of 70 lb (31 .75 kg) per 

 plot, 2,800 lb per acre (3 136 kg/ha). 



Seeding Methods 



The three seeding methods used were: 



1. Seeding by a Brillion seeder-packer followed by 

 hydromulching and fertilizing. 



2. Hydraulic seeding (Bowie hydromulcher) with 

 simultaneous mulching and fertilizing (one-step 

 method). 



3. Hydraulic seeding followed by mulching and fertil- 

 izing (two-step method). 



RESEARCH 



Research designed to devise an effective technique for 

 vegetating the mineral waste piles at Blackbird started in 

 1972 (Farmer and others 1976) and has continued until 

 the present. Nielson and Peterson (1972) demonstrated 

 that liming was necessary for initial establishment of 

 vegetation on acid spoils, and Farmer, Richardson, and 

 Brown (1976) showed that mulching and fertilizing aided 

 in establishing grass cover. It remained to be shown, 

 however, how soil organic amendment mixed into the 

 spoils and varied seeding methods could enhance 

 establishment of vegetation on this unfavorable site. This 

 paper reports results of a study using alfalfa (Medicago 

 spp.) hay as a soil organic amendment and of three 

 systems of seeding the spoils area. The study began in 

 the fall of 1973 and will continue until 1982. 



Each method was tested on both amended and non- 

 amended plots, giving a total of six combinations of 

 treatments randomly located (fig. 1). 



On all plots, the seed mixture (table 1) was applied at 

 the rate of 2-1/2 lb (1 .13 kg) per plot, or 100 lb (45.36 kg) 

 per acre (112 kg/ha). Plots planted by the seeder-packer 

 were later fertilized and mulched by the hydromulcher. 

 The fertilizer (NPK ratio: 10-34-0)|was in a slurry mixed 

 with wood-fiber mulch and a binding agent. Uniform 

 application rates were: 



Seed 



Fertilizer 



Mulch 



Binding agent 



Lb/acre 



100 

 907 

 2,000 

 40 



Kg/ha 



112 



1 016 



2 240 



44.8 



Study Site 



Experimental treatments reported here were applied to 

 a slightly sloping area 1 32 by 1 98 ft (40.23 by 60.35 m) of 



1 The use of trade, firm, or corporation names in this publication is for 

 the information and convenience of the reader Such use does not con- 

 stitute an official endorsement or approval by the U.S. Department of 

 Agriculture of any product or service to the exclusion of others which 

 may be suitable 



2 



