348 
MESSRS. J. B. LAWES AND J. H. GILBERT ON THE RESULTS OF 
in the amount taken up compared with that on plot 4-2, with the ammonia-salts and 
superphosphate only; and that increase continued, though diminishing, throughout 
the 14 years. And if, as above supposed, there were 412 lbs. residue of supplied 
potass within the soil at the commencement of the 14 years, and during those years 
the soil itself still yielded up as much as during the same period on plot 4-2, which 
had not received potass at all, there would still remain to be accounted for more than 
200 lbs. of the supplied potass at the end of the 14 years; and it may be observed 
that, in each of the three succeeding years (1876-77-78), plot 10 gave considerably 
more produce than plot 4-2. 
It would appear, therefore, that there was a considerable residue of potass remaining 
after the six years’ application ; that this was yielded up less freely than that from 
fresh supplies, but more freely in the earlier than in the later years; and that at the 
end of the 14 years a residue still remained, of which some still continued to be 
yielded up. That this should be so is quite consistent with results obtained on arable 
land, which, as already referred to, show, both in the amounts of crop and in its 
chemical composition, the effects of a residue of potass applied 25 years or more 
previously. Supposing, however, that in the presence of an artificial supply of 
potass less was yielded up from the soil itself, the residue remaining would of course 
be by so much less than 200 lbs. at the end of the 14 years. 
About an equal number of species, and nearly the same species, were represented on 
the two plots 9 and 10—the one with the continuous, and the other with the tempo¬ 
rary supply of potass; but on neither was the total number much more than half as 
many as without manure. As on plots 5 and 4-2, the one with ammonia-salts alone, 
and the other with ammonia-salts and superphosphate, so now when, with these, salts 
of potass, soda, and magnesia, are also used, the herbage has become more and more, 
and very prominently, gramineous. But whilst without the alkali-salts, in the later 
years about 80 per cent, of the total produce was made up of two grasses, yielding a 
stunted, dark-green, and almost exclusively leafy, herbage, with them the produce was 
very much more mixed, and the bulk was made up of many more grasses, few of which 
are in undue prominence. 
Thus, the six grasses which have of late years become the most prominent on plot 9, 
with, besides the other manures, an excess of potass every year, are (and somewhat 
in the following order), Poa pratensis, Agrostis vulgaris, Festuca ovina, Dactylis 
glomerata, Avena elatior, and Holcus lanatus ; and they together average more than 
80 per cent, of the produce. Again, the seven which have become, or remain, the most 
prominent on plot 10, with the discontinued supply of potass, are —Festuca ovina, 
Agrostis vulgaris, Alopecurus pratensis, Avena elation, Poa pratensis, and (in a less 
degree than any of the six on plot 9) Holcus lanatus, and Dactylis glomerata, which 
together make up about as much as the six on plot 9. The chief differences between 
the two plots are, that whilst Alopecurus has much increased on plot 10, there is 
