24 K.rj)rriniciit.'^ in'f/i different Top-Dressinr/s vpon IVhcdt. 
llioiofore bp an invariablo rule to mix nitrate of soda with salt, 
when it is to be used as a top-dressing for wheat. 
5. Salt alone, practically speaking, hardly produced any increase 
in the yield of grain, and slightly diminished the produce in straw. 
Salt, aj)plied in any quantity to cereal crops and to grass-land, 
certainly does not increase the produce. By checking oyer- 
luxuriance it, to a certain extent, preyents the growth of jank 
grasses, and produces a finer herbage ; and in the case of cereal 
crops keeps the straw shorter, and thereby prevents their getting 
lai(l at haryest-time. 
(5. Peruvian guano stands second on the list in point of effi- 
ciency. It gave, indeed, a very good result, having produced an 
increase of 12^^^^ bushels of corn and 8 cwt. of straw, at a cost 
of 1/. Us. Qd. 
7. Ammoniacal salts and nitrate of soda appeared to increase 
very considerably the produce in straw. Top-dressings, con- 
sisting chiefly of ammoniacal compounds or nitrates, should 
therefoi'e l^e used in moderate quantities. If large quantities are 
put on the land, the sample of wheat is injured and the crop 
Sikely to fall down, especially in wet seasons. 
8. Where soot can be purchased at from 6r/. to 8c?. per bushel 
it may be used with advantage, at the rate of 30 to 40 bushels per 
acre, as a top-dressing for wheat, when a larger outlay of money 
cannot be commanded. 
To enable the reader to catch at a glance the relative advan- 
tages and the clear profit which was realized by each of these 
top-dressings, I have constructed the following table. The wheat 
is valued at 645. per quarter, the average price in the market at the 
time when it was threslied, and the straw at SOs. per ton, as a 
usual selling price : — 
Tab I,;-: showing the. Money Value of the Increase in Corn and Straw per Acre 
over the Unmanured Plot in Experimental Field, and the Clear Profit 
after deducting the price paid for Manures. 
\ 
riot. 
Money Increase in 
Ciist of 
Top-dicssings. 
Clear Profit. 
Corn. 
Straw. 
I. 4 cwt. of -H-lieat-mamiro 
II. 'Ih cwt. of Peruvian auauo 
III. cwt. of nitrate of soda 
jy ;(3 cwt. of salt and \h cwt.! 
■ I of nitrate of soda ../ 
£. s. J. 
3 4 0 
4 16 9^ 
4 1 4" 
5 8 0 
0 10 0 
£. s. d. 
0 9 4J 
0 12 .'U 
0 16 r 
0 19 2 
loss 
0 4 11 
£. (/. 
1 12 () 
1 12 6 
1 10 0 
1 13 0 
0 3 0 
£. s. d. 
2 1 4i 
3 16 7 
3 7 5 
4 14 2 
0 2 1 
VI. j Unmanured I .. 1 
VII. '"'P'^^^e 4 0 0 i 0 U; 4 I 16 0 3 0 4 
\ ammonia | 
VIII. 32 bushels of soot .. .. 3 1 4 ' 0 10 2 I) IG 0 2 15 6 
