SUPERPHOSPHATE FOR PASTURES

Hauraki Plains Gazette, Volume XXXX, Issue 5479, 25 September 1929, Page 4

SUPERPHOSPHATE FOR PASTURES

HEAVY DRESSINGS PROFITABLE PRODUCE MORE BUTTERFAT How much fertiliser is it profitable to a pply to pastures ? Here lies the essential test of top-dressing practice from the viewpoint of farm economics. The application of, say, 2cwt. per acre of such a standard top-dressing as superphosphate will produce usually a result that is easily visible in both increased yield and in a beneficial change in the nature of the plants composing the sward. The application of 4 cwt. per acre of superphosphate will likewise usually show a visible increase in yield over that dressed with 2 cwt. per acre. When the results of a dressing of 6 cwt. per acre are compared with the results from 4 cwt. per acre, the increase may not be so easily visible. HOW MUCH TO APPLY Now comes the question of how much increase is visible to the eye. It is usually accepted that increases of 20 per ceikt. in yield are visible. An increase of under 20 per eent. in yield is either not easily seen, ot is invisible. • Yet an increase in yield due to the application of greater amounts of superphosphate than are usually applied, although not perhaps visible, may be very profitable, both on account of the increase not only in the quantity, but also in the nutritiousness of the herbage. The exact quantities of superphosphate which may be profitably applied are as yet unascertained, but it will probably be found that the application of o to 6 cwt., per aere per annum in one dressing will prove profitable. However, modern practice shows that more frequent dressings than one per annum give the quick growth of pasturage desired by the dairy farmer, so that two dressings—one in spring and one in autumn —of 3 to 4 cwt. each will, very probably, be found to be the best practice when using superphosphate. This double heavy dressing is particularly applicable to heavily-stocked dairy pastilles, for, the larger number 1 of stock carried the greater will be the mineral depletion of the pastures. PRODUCTION THE CRITERION The real value of a top-dressed pasture does not lie in the visible quantity of herbage produced, but in the amount of butterfat such a pasture will produce. A high standard in this direction can be readied only on closely grazed pastures which are rich in minerals.

The time will come when he who aims at 2001 b. of butterfat per aere will topdress thrice annually with o cwt. ot superphosphate per acre at a cost equal to the value of 501 b. of butterfat, thus leaving a very substantial profit per acre.