1322 
MESSRS. J. B. LAWES, J. H. GILBERT, AND M, T. MASTERS, 
the double nitrate Centaureci nigra, though it increased, occurred in only small average 
proportion, hut with the smaller quantity it became, in the third separation-year, not 
only the most prominent of the miscellaneous plants, but in that year it contributed 
about 10 per cent, of the total produce of the plot. With the double nitrate both 
Rumex Acetosa and Plantago lanceolata yielded considerable average proportions, but 
each declined very much in the third separation-year. With the single nitrate they 
also declined in the third, but again rose in the fourth separation-year; the Plantago 
yielding nearly 8 per cent, of the total produce in that year. Of the species of 
Ranunculus , R. acris gained ground, and R. repens and R. bulbosus declined, with the 
double nitrate, whilst with the smaller quantity R> repens and R. bulbosus yielded 
fairly average amounts throughout. Of other miscellaneous species, Achillea Mille¬ 
folium was about equally favoured on the two nitrate plots; but Conopodium 
denudatum was much less prominent with the double than with the single nitrate. 
The columns showing the increase or decrease in the actual yield of each species 
under the influence of the smaller amount of nitrate (plot 17), as compared with the 
larger amount (plot 15), bring to view the difference in the herbage in the two cases 
still more strikingly. It is there seen how much larger an actual amount of Alopecurus 
pratensis, and how much smaller an amount, especially of Festuca ovina, but also of 
Poa trivialis, Bromus mollis , and Lolium perenne , was grown with the smaller than 
with the larger amount of nitrate. Again, among the miscellaneous plants, Centaurea 
nigra in each year contributed much more. Conopodium denudatum , Ranunculus 
repens and R. bulbosus somewhat more, but Cerastium triviale much less, with the 
smaller quantity of nitrate. 
The general result is that there was a more mixed and better description of herbage 
with the smaller than with the larger amount of nitrate of soda, as there was a better 
with the larger amount than v 7 ith the same amount of nitrogen applied as ammonia- 
salts. 
From the particulars of the amounts of produce, and of their chemical and botanical 
characters, which have been enumerated and compared, it is to be concluded that the 
much more favourable conditions of growth which were induced under the influence of 
the larger amount of nitrogen as nitrate than with the same amount as ammonia-salts, 
also obtained when the smaller amount was used. Indeed, they were obviously 
developed in a greater degree proportionally to the amount of nitrate used with the 
smaller than with the larger quantity, and in some particulars, especially in so far as 
the botany of the plots is concerned, not only proportionally, but actually more with 
the smaller than with the larger amount. This result is doubtless due to a less forced 
luxuriance with the less excessive application of nitrate, and coincidently a more 
favourable balance of available mineral constituents. 
