STANDARDS FOR MAM RES.

Otago Witness, Issue 2811, 26 August 1908, Page 6

STANDARDS FOR MAM RES.

The recent convictions of North Island manure vendcrrs for selling fertilisers which did not conform to the guarantees under which they were sold should awaken farmers to the importance of taking precautions to see that they are not similarly imposed- upon. In the cases referred to the particular article — Thomas's phosphate, or basic slag — was purchased from reputable . agents, who obtained tlieir supplies trbm affirm of the highest standing in the Dominion, who m. turn imported it from * a firm />£ __ equal standing at, Home. The guaranfeect analysis of the slag accompanied ther article through the -various hands ; and it may be taken that it was with greafc astonishment that all parties learned^ that the fertiliser was deficient by about onehalf in its main fertilising constituent (phosphoric anhydride). Probably few farmers know even approximately what - the constituents of any fertiliser should ■ be, or the intrinsic value of a fertiliser of any given analysis. It should not be beyond the scope of the Agricultural Department to publish standards for the different manures sold in the Dominion, with their components, stated in plain terms and the value of each constituent and of the whole compound. Farmers would then have an easily understood guide to what they were buying and the price they should pay. An analysis or a standard expressing the constituents of a manure in chemical hieroglyphics is of little use to the ordinary farmer, and the standards or analyses should not only give the particulars in plain English, but should also state the percentage which is immediately available for plant tood. Brief but clear directions for mixing the various manures might well be. added to the leaflet or card, and this also would save many farmers from making mistakes which may cause them trouble and loss. Meantime "it may be stated that basic slag of average quality should contain prosghoric acid, 18 per cent. ; lime, 50 a per cent. ; silicate, 15 per cent. ; magnesia, 3 'per cent. A high grade sample may contain 22 per cent, phosphoric acid, but it is possible that the quantity of this which is available may be no greater than in the average sample (say, 16 per cent, to 18 per cent.). The unit value of phosphoric acid in New Zealand at present is 6s, from which the value of the slag can be easily calculated. It may also be stated that 'there are being sold in the Dominion at the present time a number of very low-grade slags, of the quality of which the importers cannot plead ignorance, and with regard to which it behoves the buyer to be on the alert.