AGRICULTURAL EXPERIMENTS.

Temuka Leader, Issue 2321, 20 February 1892, Page 3

AGRICULTURAL EXPERIMENTS.

(Home Correspondent of the New Zea land Herald.) Sir John Lawes has issued the annual report of his multifarious experiments, bringing the records up to the end of 1890. Some of tnom were commenced as long ago as 18415. The results of those relating to permanent pasture are given for the twenty-two years ended with 1875 for the fourtpen years ended with 1879 and fur 1880 alone. Let us take those for the fourteen years, as giving the latest averages, On two plots never manured since the experiments commenced the average yield of hay yor acre, for two cuttings per annum, was 28cwt. W here superphosphate of lime alone was applied at the rate of oiewt per acre per

annum there was no increase, and 4001 b of ammonia salts (half sulphate and half muriate) gave only a trifling increase of hay, whereas 51b of nitrate of soda brought the average yield up to 40cwt. Where an expensive dressing of sulphates of potashs, soda, and magnesia, with 3A cwt of superphosphate, was given, the yield rose to But a better result in proportion to the cost was that of 49cwt as the fourteen years annual average result from the application of 3271bs of nitrate of potash and 3icwt. of supephosphate. The greatest average yield of all was 86 1 but this was dearly bought at the cost of an enormous dressing per annum of 5001 b of sulphate of potash, 1001 bof sulphate of soda, 1001 b of sulphate of magnesia, 3£ cwt of superphosphate, 6001 b of ammonia salts, and 5001 bof silicate of soda. In another field, where experiments in barley had been tried for 48 years, the averages for 38 years are given. The averages for two plots never manured during that period of continuous growth of barley was slightly over 17 J bushels an acre. An annual dressing of 3-j cwt of superphosphate per acre alone in- • creased the yield to 21 f bushels, and 2751 b of nitrate of soda alone to 32f bushels; but when those two quantities of superphosphate and nitrate of soda were combined the yield x'ose to 45f bushels the best result in proportion to cost of manuring obtained of any of_ the numerous plots. Smaller quantities, it must be borne in mind, would have given eqxxally good results under a rotation of cropping, ixxstead of where barley has been grown every year for a very long period; and this remark applies to all the experiments on corn. The greatest yield of all was from the annual application of 14 tons of farmyard manure, namely, 49 bushels; but the cost was more than double that of the superphosphate and nitrate of soda, and, therefore, did not pay nearly as well. Yet, as the extra yield over that of the xxnmauured plots was fully 31 bushels an acre, the value, at 4s a bushel, would be £6 4s an acre, while the manure and spreading would be valued at about £3lss or £4. Ammouia salts did not give as good results as nitrate of soda. In the expex’iments with wheat the average annual yield during 38 years of continuous cropping was 13j|- bxxshels an acre where no manure was applied in the whole period. This was raised to 34 bushels by the annual application of 14 tons of farm yard manure, yielding but a small profit at current prices for wheat, but paying well when wheat was over 40s a quarter all round—the present average is 36s 7d. The most costly of all the mixtures of artificial manure produced xxo more than 361 bushels ; but only a bushel less was obtained from the use of 2751 b of nitrate of soda, Slcwt of superphosphate, 2001 b of sulphate of potash, and 100 B) each of sulphate of soda and magnesia. It is unfortunate that there was no trial of nitrat > of soda and superphosphate without the three other manures, which may possibly have been superfluoxxs.