128 PRESIDENTS ADDRESS—SECTION G. 
end of April, so that only 10.1 in. fell from the time the wheat 
was sown until it was harvested. The reserve from preceding 
years also could not be much, as in 1897 the total was 12.1 in., 
and in 1898 it was 17.7 in. In spite of the fact that the rain- 
fall was small—2.2 in. below the average—the increase of grain 
from a dressing of 2 cwts. of mineral superphosphate per acre 
was 12 bushels 32 lbs. per acre, and from 2 cwts. of basic slag 
it was 8 bushels 46 Ibs. per acre. When # cwt. of sulphate of 
ammonia was added to the 2 cwt. of superphosphate, the increased 
yield over that of the superphosphate alone was only 11 Ibs. per 
acre, and 1 ewt. of nitrate of soda added to the 2 cwts. of basic slag 
gave an increase, compared with basic slag alone, of 25 lbs. per 
acre. The inference from these results is necessarily that 
nitrogeneous manures are not profitable, are, in fact, not 
required. The results of nitrification in the soil was sufficient 
to furnish nitrates to the light crops, which, owing to the 
deficiency of phosphates, and low average rainfall, and his 
practice of fallowing, the farmer had been in the habit of 
harvesting. A condition of things somewhat similar to this 
prevails over a large proportion of the drier wheat-growing 
areas. Had the yield been submitted for some years to vigorous 
farming, and heavy crops, as the result of phosphatic manuring, 
removed in each two years, with occasionally a summer crop on 
the fallow, the effect of nitrogenous manures would have been 
more marked. In 1888 I had some test plots in a field that had 
been cropped thus for eight years, and the result of # cwt. of 
sulphate of ammonia, added to 2 cwts. of superphosphate, was 
that the yield for the mixture of manures was 22 bushels 39 Ibs. 
per acre, while the yield from superphosphate alone was 19 
bushels 42 Ibs. But this is an exceptional case. When the 
practice of cropping is one crop in three years, and that after 
fallow ploughed for the first time early in the rainy season, I 
believe it will be found that there is relatively very little re- 
sponse in the crops to dressings of nitrogenous manures. In the 
absence of underdrainage of our lands, or of serious leaching in 
any form, the natural nitrates will suftice, or well-nigh sutfiice, 
to furnish the necessary nitrogen to the crop. 
It is for phosphates that the demand in a large proportion 
of our Australian soils is strong. Considered in relation to the 
climate, the application of phosphates to the soils deficient in it 
is particularly to be recommended. Phosphatic manuring in 
this climate has really a triple, or even fourfold, significance. 
Phosphoric acid is an element of plant food; it encourages 
vigorous action of the soil ferments; it promotes tillering and 
hastens maturity ; and, lastly, and by no means of least impor- 
tance, in view of our climate, it enables the plant to build up its 
tissues, and develop ‘he grain with a less transpiration of water, 
and therefore is a means of enabling the plant better to with- 
