On Permanent and Temporarij Meadows and Pastures. 205 
Dry 
Hat 
Yield per Acre. 
Surplus due to 
Manure. 
With mineral manures (potash, phosphoric acid,) 
and magnesia, renewed annually) .. ../ 
1 
1 
0G2 
7G5 
tons 
) ) 
703 tons 
With nitroi^enous manure alone : 
1 
1 
314 
769 
> ) 
J ) 
252 ,, 
707 
With nitrogenous and mineral manures : 
1. Mineral manures and salts of ammonia .. 
2. Mineral manures and nitrate of soda 
2 
2 
545 
857 
) ) 
1 
1 
480 ,, 
795 
If it is true that mineral manures are alone sufficient to give 
an extra annual return of "TOS tons per acre on the first mowing 
(this being the only mowing of which an account was taken, the 
aftermaths having been depastured), it is no less true that nitro- 
genous manures, added to the mineral manures, have raised 
this surplus to 1*483 tons per acre in the case of the salts of 
ammonia, and to 1"795 tons per acre in the case of nitrate 
of soda. To these facts, carefully verified, the experience of 
farmers must be added, for they use on certain grass-lands 
manures almost exclusively nitrogenous, such as dried blood, 
sulphate of ammonia, nitrate of soda, &c. 
I am warranted in stating that these manures would not 
produce such effects if the soil was not also abundantly fur- 
nished with the necessary mineral elements, and that the 
employment of nitrogenous manures alone, tends to the rapid 
exhaustion of those elements, which are not returned to the 
soil. But it is certain that if the nitrogenous manures did not 
produce an increase in the crop, at least to the extent of their 
value, farmers would long ago have ceased to use them. It is 
therefore certain that nitrogenous manures do exercise a favour- 
able influence on the development of grasses, when the mineral 
elements indispensable to them are not wanting. Is it necessary 
then to supply to grass-lands, in addition to the dressings of 
mineral manures mentioned above, the whole of the nitrogen 
necessary to the crop ? If this were so, the cultivation of grass- 
lands would become unprofitable. 
We have seen that 10 tons of dry hay contain 384'38 lbs. of 
nitrogen. In a soluble condition, this element, according to 
current prices and distance from the manufactory, costs from 
lOf (/. to I5. Id. per lb. delivered, say an average of I5. If then 
we had to supply to the soil all the nitrogen required, we 
