205 
green crop while it is still succulent (September and early Octo- 
ber). When searifying the planted land in the spring a dise 
cultivator gives very good results for the reason that it chops up 
the crop without getting tangled up in the vines. 
Green manuring may, under particular circumstances, be 
detrimental. In localities of short rainfall it may !ead co the 
desiccation of the soil. It is calculated that one part of dry 
vegetable matter requires 300 to 500 times its own weight of 
moisture, so that every ton of green manuring erop in a dry 
locality would absorb 300 to 500 tons of water; and unless plenti- 
ful rain or abundance of artificial water can be relied upon, the 
process may in some cases be detrimental. 
The results of commercial fertilisers are much more marked 
when applied on land well stocked with humus than when used on 
land depleted of vegetable mould. 
VALUE OF FERTILISERS. 
Under the Fertilisers and Feeding Stuffs Act it is imperative 
on the manure vendors to furnish with the invoice for any fertil- 
iser sold a certificate showing the per cent. of nitrogen, phosphoric 
acid (soluble and insoluble), and potash contained in the manure. 
Mention of any other ingredient is of little or no value, and may 
be considered as so much padding, which is liable to confuse the 
purchaser. Failure to comply with this enactment may be meted 
out by a £20 fine. The more concentrated the fertiliser is, as re- 
gards any one or more of the three elements mentioned, the more 
valuable it is, so much less dead weight having to he handled and 
carried to the field. 
The value of the three chief elements of a fertiliser—viz., 
nitrogen, phosphoric acid, and potash—is not uniformly the same, 
and is mostly influenced by sea and railway freight, and by its 
degree of solubility. The market quotation is expressed at so 
much a “unit.” The unit value being the value of one per cent. of 
the particular ingredient in a ton of manure. 
Nitrogen in sulphate of ammonia or in nitrate of soda or of 
potash is worth in Western Australia 16s. to 18s. per unit. In 
blood, bones, or offal (ground fine) it is worth 14s. in this State.* 
If we express by 10 the worth of nitrogen in nitrate of soda, 
of potash, or of sulphate of ammonia and of ammonia in live 
guano, the nitrogen in blood and bones or meat is only worth 7, 
while in wool waste, hair, horn, and leather it comes down to only 
2 or 3, that is to say:—If an application of nitrogen under the 
form of nitrate of soda, or the substances grouped with it, would 
produce a surplus crop of 1,000]bs. of fruit, an equivalent amount 
*Note.—These are pre-war prices and fluctuate from time to time. 
