CROP TRIALS

Wairarapa Times-Age, 22 October 1941, Page 7

CROP TRIALS

SERPENTINE SUPERPHOSPHATE WAIRARAPA EXPERIMENTS. THE POSITION REVIEWED. In last month’s “Journal of Agriculture,” a comprehensive report was published of the results of trials with serpentine superphosphate throughout New Zealand. A separate report of the four Wairarapa trials may, however, be of interest, states Mr N. Lamont, of the Department of Agriculture, Masterton. Four crop trials were laid down last season —one at Eketahuna, one at Masterton and two near Carterton, the crops being swedes, wheat, turnips and chon moellier. There trials were all laid down on the “half-drill strip” method in which the drill is divided in half and the two manures sown together, resulting in a series of paired strips running across the area. The results of these trials were as follow: — 1. Swedes.—Unfortunately the proprietary manure used with the Eketahuna trial was rather “green” and did not run through the drill as freely as the serpentine super. As a consequence the former ran out at 3cwt per acre and. the latter at scwt per acre—with the result that the yield difference in favour of the serpentine super was more or less meaningless. The interesting feature of this experiment was the fact that despite the heavy manure sowing, the germination on the serpentine super plots was nearly twice as good as that on the proprietary manure plots. 2. Wheat. —In the wheat trial at Upper Plain; the serpentine super • was compared with basic slag and although the latter ran out at a slightly lower rate per acre, it outyielded the serpentine super by a little over 4 bushels per acre for a 50 bushel per acre crop. This was rather a surprising result and it so happens that nowhere else in New Zealand was serpentine super compared with slag. In all the other experiments, the other manure was plain super or reverted super, and yields of serpentine super were on much the same level as these. 3. Chou moellier.—ln this trial the germination and yield of the serpentine super plots was substantially better than those of proprietary manure with which it was compared. The germination when using serpentine super was roughly 25 per cent better (actually 11 plants per 10 feet of drill better) and the yield 6 tons per acre better on a 28-ton per acre crop. 4. Turnips. —In this case the yield and. germination differences were small and slightly in'favour of the proprietary manure which was being compared with the serpentine super. The yield difference was, however, hardly great enough to be regarded as significant, being 1| tons per acre on a 21ton per acre crop. SUMMARY. It is quite obvious from the variable results that have been obtained that dogmatic statements cannot be made without further investigation over more than one season. It can, however, be quite definitely stated that better germinations of fodder crops are likely to be obtained with serpentine super than with straight super or proprietary mixtures. So far as yields are concerned the local experiments are inconclusive by themselves but considering them in conjunction with results throughout the Dominion, it can be said that serpentine super can be used with every confidence, that yields will differ little if anything from those obtained with ordinary mixtures. Perhaps a word could be said about proprietary manures. It is, I think, understood that as a matter of policy the Department does not specify the actual brand of a mixture that may be used in a trial. Over the whole of New Zealand, serpentine super has generally been better than these patent mixtures —so far as Wairarapa yields are concerned, the serpentine super was much superior in one experiment and very slightly inferior in another—despite the fact that in these two experiments the same brand of proprietary manure was used. Two further points should also be borne in mind. First, the shortage of certain crop seeds makes it highly important to obtain maximum germination and secondly, that under the rationing scheme, 27 cwt. of serpentine super can be obtained for each ton of “straight’ super allowable. In view of these two factors and the satisfactory crop yields generally resulting from the use of serpentine super, it can be expected that a substantial amount of this new product will be used this season.