Hydroseeded plots (methods 2 and 3) were planted by 

 the Bowie hydromulcher. In method 2, seed, fertilizer, 

 mulch, and binding agent were mixed together in the 

 hydromulcher and applied as a slurry in a single 

 operation (one-step method). The plots seeded by the 

 two-step method (method 3) first received seed and 

 water applied by the hydromulcher, then a slurry of 

 fertilizer, mulch, and binder was sprayed over the seed at 

 the standard rates of application. 



Two years after seeding, the area began to reacidify 

 and Richardson recognized that the present method of 

 lime determination was not satisfactory. After incubating 

 a sample of the spoils, it was determined that at least 4 

 more tons of calcium carbonate (CaC0 3 ) per acre (8 960 

 kg/ha) should be added to the test plots. The entire 

 surface area was relimed at this rate. Later, a more 

 accurate method of determining lime reguirements for 

 these spoils was developed (Sorensen and others 1 980). 



DATA COLLECTION 



Data on grass production were collected in the 

 summers of 1974 and 1979 by a double sampling 

 technique utilizing a Neal capacitance meter (Neal and 

 Neal 1973). Additionally, in 1979, we collected data on 

 individual grass species. 



RESULTS AND DISCUSSION 

 Production 



Total production of grass, by plots and treatments, is 

 summarized in table 2 and figure 2. The decreased 

 production in 1 979 was due partly to unfavorable weather 

 (precipitation was 22 percent less than the 4-year 

 average) and to the reduction in plant nutrients. Other 

 factors, such as reacidification, probably contributed. 



o 

 id 

 \ 

 w 

 ja 



z 

 o 



M 



U 

 P 



o 



0_ 



700 

 650 \ 



600 



550 



500 



450 



400 



350 



300 



250 

 200 



LEGEND 

 1974 1979 



T7777X VZZM 



TH-NA 



TH-A 



SH-NA SH-A 

 TREATMENT 



SP-NA 



SP-A 



Figure 2. — Average grass production by treatment at Blackbird Mine, 1974 and 1979: SP, seeded by seeder- 

 packer, followed by application of mulch and treatments; SH, hydroseeded, followed by hydromulching and ferti- 

 lizing; TH, seed, mulch, and fertilizer all applied by hydromulcher in one operation; A, amendment by addition of 

 hay; and NA, no amendment. 



4 



