50 
SIR J. B. LAWES AND PROFESSOR J. H. GILBERT ON THE 
(= 496 lbs.),'and after the beet and maize 615 kilog. per hectare (= 549 lbs. per 
acre) per annum. 
Lastly, without any manure, the losses Avere, after 3 years of green maize 
379 kilog. per hectare (= 338 lbs. per acre), after 3 years of potatoes 307 kilog. 
{= 274 lbs.), and after 3 years of beet and 1 year of maize, 476 kdog. per hectare 
(= 425 lbs. per acre) per annum. 
Over the next 4 years, without further manure on the previously manured plots, 
and still without manure on the previously unmanured plots, the losses of nitrogen 
by the soil though still large, were generally much less. Besides that in the crops, 
they were per annum as follows :— 
After farm-yard manure, with green maize 133 kilog. per hectare (=119 lbs. per 
acre), and with potatoes 2 years and wheat 2 years 308 kilog. per hectare (=: 275 lbs. 
per acre). 
After nitrate of soda, with green maize 4 years 206 kilog. per hectare (= 184 lbs. 
per acre), and with potatoes and wheat, 38 kilog. per hectare (=34 lbs. per acre). 
After ammonium sulphate, with green maize, 148 kilog. per hectare (= 132 lbs. 
per acre), and after potatoes and w'heat 140 kilog. per hectare (= 125 lbs. per acre). 
Without manure for 7 years, the annual loss over the last 4 years was with maize 
104 kilog. per hectare (=93 lbs. per acre), whilst with potatoes and wheat there was 
a gain of 9 kilog. per hectare (=8 lbs. per acre). 
All the losses during the 3 years of the application of the manures, and especially 
those after 3 years of beet and one year of maize, are far in excess of anything that 
has come within our own knowledge and experience, and they are in amount such as 
reflection must show cannot possibly occur in actual practice. 
For example, although it is estimated that the farm-yard manure ’supplied 
1200 kilog. nitrogen per hectare (= 1071 lbs. per acre), in the 3 years, and that only 
451 kilog. per hectare (= 403 lbs, per acre) were removed in the 3 crops of green 
maize, leaving a balance of the nitrogen of the manure of 749 kilog. per hectare 
(= 668 lbs. per acre), yet the surface soil was estimated to lose, not only this amount, 
but 116 kilog. per hectare (= 104 lbs. per acre) more, or in all 865 kilog. per hectare 
(= 772 lbs. per acre) in the 3 years. Again, with the same supply, 1200 kilog. 
nitrogen per hectare (= 1071 lbs. per acre) by manure, in 3 years, and the removal of 
561 kilog. per hectare (=501 lbs. per acre) in beet and maize in 4 years, leaving a 
balance from the manure of 639 kilog. (= 570 lbs.), the soil is estimated to have lost 
2076 kilog. (= 1854 lbs.) more; or in all 2715 kilog. (= 2424 lbs.). It is true that 
when excessive amounts of farm-yard manure are applied there will probably be some 
loss by the evolution of free nitrogen, but here the estimated losses amounted to much 
more than the total nitrogen of the manure after deducting that removed in the 
crops. Indeed, M. Deherain calls attention to the fact that, according to the 
figures, one-fourth of the^total nitrogen of the surface soil has been lost! We repeat 
that such losses certainly do not occur in practical agriculture. But, if such loss could 
