Urawrord.—Growth of Cereals in New Zealand. 149 
The snags cast up after every flood will no doubt dangerously affect the 
groynes when first constructed, as they would then have a large portion 
above the surface of the beach, but such risks must be unavoidably 
encountered. Hurriedly constructed works such as have hitherto been in — 
vogue are seldom satisfactory, for permanent results can only be obtained 
by a system of management pursued when opportunity favours, the best 
time for constructing the groynes being at the period of extension of beach. 
Arr, XIIL—How New Zealand may continue to grow Wheat and other 
Cereals. By James C. CRAWFORD. 
[Read before the Wellington Philosophical Society, 8rd August, 1878.] 
Wz have all heard of the exhaustion of soils in new countries from the 
system of taking crop after crop of the same grain off the land year after 
year without manure, so that eventually the richest soils have been 
reduced to a barren state, and have refused any longer to yield returns to 
the husbandman. 
Thus the fertile bottoms of Virginia were impoverished—although, I 
believe, it was by tobacco and not by grain—and thus the former wheat- 
growing lands of Campbeltown and Appin, to the southward of Sydney, 
now refuse to grow wheat, and are only used for the growth of oaten hay, 
which, the grain not being ripened, takes little out of the soil. 
The immense wheat-fields of South Australia, which now give so large 
an export to that colony, must, in course of time, share the same fate, if 
continued on the same system, and even now the yield per aere is very 
small. 
Wheat-growing has become an important industry in New Zealand, and 
the returns from the provincial districts of Canterbury and Otago have for 
several years past been very large. 
New Zealand soils will not long, however, stand the system of cropping 
above described, for a very few years will exhaust the constituents required 
for a grain crop. Let us consider, however, how grain-cropping in this 
colony can be put upon a permanent footing. 
We must not be too hard upon the farmers who exhaust their soils, and 
supply no manure to make up the waste, because, from the system of 
farming necessary in a new country, it is not easy, perhaps it is impossible, 
to obtain the required supply of manure. In Great Britain and other 
thickly-peopled countries, the farmer lays his plans to provide a supply of 
manure for himself, He has either a dairy, or he stall-feeds oxen, or he 
