512 
Report of Erperiments unth different Manures 
It would be far too expensive to supplv in tkis wav all the 
constituents that are requisite for the production of such, 
crops without undue exhaustion of the soil, or deterioration 
in the character of the herbage. Artificial manures can, 
as a rule, onlv be used with advantage and economv for the 
hay crop, when the land receives periodicallv a dressing of 
stable or farmyard manure. Such manure restores the mineral 
constituents taken from the land in the crop more completely, 
and some of them more economically, than any other ; it at the 
same time supplies a large amount of available nitrogen, and of 
organic matter yielding by its decomposition carbonic acid, and 
is calculated to favour a more complex and generally a superior 
description of herbage. 
Plot 14 received the same description and amount of mineral 
manure as Plots 8, 10, 12, and 13ff, and, in addition, nitrate of 
soda containing about half the amount of nitrogen supplied in the 
ammonia-salts of Plot 10 ; and Plot 15, with the same mineral 
manure, had, in addition, double the amount of nitrate — that is, 
about the same amount of nitrogen as that in the ammonia-salts 
of Plot 10. These experiments, like those with nitrate of soda 
alone, were commenced only in 1^58, two vears later than most of 
the series. The figures show an average over the five years of 
44 cwts. of hay per acre per annum with the smaller amount 
of nitrate, and the mineral manure, and of oli cwts. with the 
larger amount, against o6|^ cwts. with the same mineral manure, 
and ammonia-salts equal in nitrogen to this larger amount of 
nitrate. 
Ammonia-salts, in conjunction with the mixed mineral manure, 
have, therefore, given a larger amoimt of produce than an equal 
amount of nitrogen in the form of nitrate of soda. The descrip- 
tion of herbage developed was, however, strikingly different in 
the two cases, and very different also with the smaller and the 
larger amounts of nitrate, as will be found by reference to the 
last number of the Journal. It should be added, that there is as 
vet no evidence of diminution of produce from year to vear where 
the nitrate (either in the larger or the smaller quantity^ was used 
in conjunction with the mixed mineral manure. 
The plots manured with farmyard manure remain to be con- 
sidered. The amount annually supplied (14 tons) would contain 
more of everv mineral constituent, and considerablv more nitrogen, 
than the produce obtained by its use, besides a large quantity of 
organic matter yielding by its decomposition carbonic acid and 
other products. \^Tien the farmyard manure was used without 
the addition of ammonia-salts, the average annual produce 
amounted to only about 42^ cwts. of hay, or to less than 1 ton 
above that without manure, and to considerably less than was 
