Recent Agricultural Puhlications. 407 
benefits it was hoped to derive from the use of the chemical 
manures. 
Great as is the risk attending the exclusive use of chemical fer- 
tilisers, there is no gainsaying their value when employed in con- 
junction with farmyard manure, for they are admirably suited to 
make good the deficiency of phosphorus and of potash in the latter. 
Moreover, although the ammoniacal or organic nitrogen of farm- 
yard manure is capable eventually of being assimilated, this can 
occur only after nitrification has taken place. But for this pro- 
cess certain conditions of moisture and temperature are indispen- 
sable. In a cold dry spring, therefore, the nitrogen of farmyard 
manure becomes available only very slowly, and that at a time when 
the young plant has need of an abundance of food. Consequently, 
at such a period, the application of a moderate dressing of nitrate of 
soda is capable of exercising a decisive influence. 
Of numerous examples of the value of farmyard manure and 
chemical fertilisers used simultaneously, we quote tlie following, 
obtained by M. Deherain at Blaringhem. The yields are given in 
kilogrammes per hectare (1 kilogramme = 2’2 lb. ; 1 hectare = 2 
acres 1 rood 35 poles), and as it is the comparative values which are 
of interest, there would be no advantage in 
converting 
the figures 
into their English equivalents : — 
Grain, kilog. 
straw, kilog. 
Farmyard manure alone .... 
. 3,G40 
5,900 
Ditto 
. 3,750 
G,000 
Farmyard manure, sulphate of ammonia, and 
supeiq)hosphate of lime , 
. 4,900 
8,800 
Ditto 
. 4,800 
8,G00 
Farmyard manure, nitrate of soda, .and super- 
phosphate of lime .... 
. 4,750 
10,100 
Ditto ....... 
. 4,750 
8,400 
Farmyard manure, sulphate of ammonia, super- 
phosphate, and chloride of potassium 
. 4,G50 
8,400 
Ditto 
. 4,8-50 
9,500 
It is seen that the yield was increased one-third by associating 
with the farmyard manure chemical fertilisers containing nitrogen 
and phosphorus. The soil at Blaringhem is very clayey, and has 
no deficiency of potash ; consequently the addition of chloride of 
potassium produced no marked efiTect, and was unnecessary. 
The great advantage, it is pointed out, of chemical fertilisers is 
that, as they afiford separately the essential elements, nitrogen, 
phosphorus, and potash, it is possible to apply by their means only 
the element or elements in which the soil is deficient. Most culti- 
vators, as well as the French farmers’ syndicates, purchase the 
chemical manures in their primary forms — nitrate of soda or sul- 
phate of ammonia as yielding nitrogen, superphosphates or basic 
cinder as sources of phosphorus, and chloride or sulphate of potash 
as affording potassium — and are resorting less and less to the use of 
