Comparative Effects of cUffereiit Manures on Grass Lands. 641 
special effects of ammoniacal salts. Here [pointing to specimens] 
we liavc the produce of immamu'ctl land, and here again we have 
some of the herbage of the land to which ammoniacal salts have 
been applied. You will notice in the latter a difference in the 
colour : the grass is a deeper green ; it is also somewhat higher, and 
there is more of it. There is also this remarkable difference, that 
whereas in the unmanured portion we have great variety, a large 
mixtiu'e of plants, through the application of ammoniacal salts the 
herbage becomes more siuqjle. When ammoniacal salts have been 
applied in conjunction with mixed minerals, the effect is very striking ; 
indeed the quantity of produce is double that derived from ammonia 
alone. An extra quantity of ammonia increases the produce to a very 
remarkable extent, and it fm-ther reduces the number of species of 
plants, pushing forward certain grasses to the exclusion of almost every 
other. Among the first to disappear are the leguminous plants, espe- 
cially if large quantities of ammonia are applied, even though a supply 
of mineral matter may be present, and these are among the more 
nutritive of our herbs. On the whole acre plot thus treated, which 
I saw yesterday, it would, I think, be difficult to find any clover ; and 
moreover, it is almost amusing to observe how certain grasses take the 
place of others. Thus, when a large dose of ammoniacal matter is 
used in conjimction with minerals, cocksfoot especially and tufted 
hair-grass supersede many other grasses. The specimens placed in 
bunches on the table were selected to give a general idea of the con- 
stitution of the herbage and the height which it attains on the several 
plots. 
The effects produced by nitrates seem in some degree to differ from 
those of ammonia. Nitrate of soda does not so materially affect the 
leguminous tribe of plants as do ammoniacal salts. As to mineral 
matters, phosphatic and alkaline substances may be fairly taken 
together ; for those plants which are stimulated by phosphates are 
also benefited by alkaline manures, and more especially salts of potash. 
The action of mixed mineral manures, composed of phosphate of lime 
in a soluble condition and salts of potash, on the whole clover tribe 
of plants is very remarkable. Under its influence you can see clover 
not merely here and there, but all over the plot ; while the rougher 
grasses are less luxm-iant. The cocksfoot here api)ears to be almost a 
different plant from that which received an excess of ammonia ; it is 
much lower, and not so limu'iant ; while the red and white clover 
and the wild vetch are seen all over the field. In other words, alka- 
lies and phosphates promote a good quality of herbage ; but they have 
not as great an effect upon the amount of produce. 
Eetm-ning now to the subject of the improvoment of pastures, let 
us suppose that the land has been well drained, that it is moderately 
porous, and that there is a fair depth of soil ; but that the produce is 
scanty, and the herbage not very good. How are these defects to be 
remedied ? can both be dealt with at once ? In most cases we ought, 
I think, to endeavoiu- to improve to some extent at least the quality of 
om- herbage, and at the same time try to get not an excessive but a 
remunerative amount of produce. If wc look too much to quality, 
2 T 2 
