THK ]5K< » A I )I5 A I.K WIIKAT SOILS. 
117 
Brief Examination of the Resflts Obtained in the Case of Individual 
Plats. 
Plat 3 has been unmanured for fifty years. Plat 1 has been unma- 
nured for forty years, bat previously was annually dressed with 
superphosphate and ammonium salts, and has in consequence ever 
since given a slightly better yield than plat (See Table 53.) It 
was never regularly manured with potash, but in its first year, fifty 
years prior to L893, it had a dressing of farmyard manure ashes, 
estimated to have supplied 235 pounds per acre of potash. In fifty 
years it lias yielded in its crops 87 pounds of potash per acre more 
than plat but owing to the initial supply referred to its actual loss 
in cropping has been l to pounds less per acre than thai of plat 3. 
This difference is not Indicated in the hydrochloric-acid figures, but 
it is qualitatively indicated in the surface-soil contents of citric-acid- 
soluble potash, there being found by analysis in L893in the surface 
soil an excess of ">J pounds per acre in this form as compared with 
plat 3. 
Plats 10a and ln|» have, it will he remembered, been continuously 
dressed with ammonium salts w ithout minerals, except that, while 
both plais had a dressing of minerals in IK44, plat lob was also dressed 
with minerals in L848 and L850. The effect of these two extra dress- 
ings of minerals OB the yield of plat 10b is apparent in the crops down 
to the present day. The ext ra minerals applied to plat LOb included 
300 pounds of potash per acre, and this plat has yielded in its crops, 
Up to 1893, 11~> pounds more potash per acre than plat 10a. Deduct- 
ing the excess in yield from the excess in supply, plat lob has lost 
less potash in its cmps by L85 pounds per acre than plat 10a. Here, 
again, the hydrochloric-acid results indicate no di (Terence, but in the 
citric-acid results we find that plat LOb shows 2\ pounds more citric- 
aeid-soluble potash in the first depth, and ">•'! pounds more in the 
second dept h. 
We will now compare the results of the various plats which have all 
received both phosphate and ammonium -alts, but which differed 
in their treatment as to oilier saline manures. "Fable (54 shows at* a 
glance the mineral treatment of each plat, the estimated excess or 
deficiency of potash per acre as compared with plat 11 (calculated 
from known manorial additions and crop removals), the excess or 
deficiency of hydrochloric-acid-soluble potash found by analysis 
in the first inches as compared with plat 11, and also the excess or 
deficiency of citric-acid-soluble potash, again as compared with plat 
11, shown respectively in the first, second, and third depths of 9 
inches each, and also in the total 27 inches which they comprise. 
