area (12 m 2 ) , and was an exception to the relatively uniform 

 topography of the experimental site, it served to emphasize the 

 importance of adequate drainage for plantings of Puccinellia . 



When cover is averaged over treatment for the period from 

 September 1979 to September 1980, the cover value for plugs increased 

 two fold whereas that for sprigs increased by about 40%. Average 

 survival over this same period of time was 22% higher for plugs than 

 for sprigs. Sixteen months after planting, cover for plugs was 

 significantly higher in the Mag Amp + Osmocote 3 (estimated to last for 

 3 months) treatment and for sprigs it was significantly higher in the 

 ammonium sulfate + concentrated superphosphate treatment (2.8 g N + 1.2 

 g P). The controls achieved only 14 and 33% of the cover of the best 

 treatments for sprigs and plugs, respectively, over this 16-month 

 period. 



Response to Fertilization 



Kerlavos 



Analysis of variance of cover and dry weight data of plug type 

 transplants of Puccinellia on a disturbed site at Kerlavos indicated a 

 significant response to fertilizer materials (Tables 7, 8). One year 

 after planting the cover of plugs in all three fertilizer treatments 

 containing both nitrogen and phosphorus was significantly greater than 

 that of plants in those treatments which provided only nitrogen or 

 phosphorus or neither (Table 7). These results emphasize the 

 requirement for fertilizer materials on those disturbed sites which 

 substrate samples indicated contained amounts of nitrogen and 

 phosphorus which were too low for good initial growth of transplants. 



The dry weight of aboveground plant samples from the Mag Amp + 

 Osmocote 3 slow release fertilizer treatment was significantly greater 

 than that of plants from any other treatment at 4 and 16 months after 

 planting (Table 8). Although cover in the Mag Amp + Osmocote 3 

 treatment was not significantly different from that in the two 

 conventional ammonium sulfate + concentrated superphosphate treatments 

 1 year after planting, by 16 months after planting, cover of plants in 

 this Mag Amp + Osmocote 3 treatment was significantly greater than that 

 of those in any other treatment. Cover of plants in this treatment was 

 about twice that of transplants in the second best treatment. The 

 center row of transplants (plugs) in Figure 3 3 is the Mag Amp + 

 Osmocote 3 treatment. These data indicate the advantage of a slow 

 release over a conventional fertilizer material on this disturbed site 

 for a relatively long period (16 months). We excavated the belowground 

 portion of several healthy transplants in the Mag Amp + Osmocote 3 

 treatment and noted that the fertilizer material still present below 

 the transplant could be identified after 4 months (Fig. 35). 



Cover in the control plants remained significantly below that of 

 plants in those three treatments which provided both nitrogen and 

 phosphorus 16 months after planting. Cover in these control plants was 



394 



