H.—29.

Classification of Experiments. A. Research into fundamental grassland problems being carried out at — (1) Experimental Farm, Ma.rton. (2) Farm of Instruction, Ruakura. (3) Technical College, Christchurch (co-operation with). B. Grassland investigations and demonstrations carried out by field officers of the Fields Division. C. Experiments on annual crops being carried out by field officers. D. Experiments on the manuring of fruit-trees. A. RESEARCH INTO FUNDAMENTAL GRASSLAND PROBLEMS. (1) Makton Experimental Fakm. MEASUREMENT OP PASTURE PRODUCTION THROUGHOUT THE YEAR BY MOWING WITH A LAWN MOWER. The six lines of investigation reported on last year have been continued. Slight modifications have been made in the technique. These have resulted in a more accurate measurement of total production of herbage. A Dennis motor-mower donated by Imperial Chemical Industries was received in March. The use of this machine will ensure greater accuracy of results and more satisfactory work generally. It is anticipated that a report covering work up till August, 1931, will be completed for publication about September next. (a) Trial of Effect of applying Super and Slag as Winter, Spring, Summer, and Autumn Applications respectively.—The main features of this trial are: (1) Super continues to show a consistent superiority ovej slag, especially during low-production periods; (2) the summer and autumn applications of superphosphate are most effective in increasing production during low-production periods ; (3) the total production from each treatment for a period of over two years has been worked out, and shows that the summer and autumn applications of super have caused the greatest production of herbage. The difference between these and the winter and spring applications is not very great, but combined with their superiority during the low-production periods a very excellent argument in favour of summer and autumn applications can be advanced. (6) Trial to determine Effect of Three Distributed Applications per Annum of Super, Super plus Sulphate of Ammonia, and Super plus Sulphate of Ammonia plus Potash, and to compare Ammonium Phosphate and NitrophosJca with the appropriate Mixtures above. —This experiment is proceeding satisfactorily, but there is nothing to report at the moment beyond what was reported last year. (c) Trial to determine whether a Heavy Application of Super at Infrequent Intervals is as effective as smaller Applications at more Frequent Intervals. —This trial was commenced in August, 1929. The treatments are arranged so as to apply 4 cwt. of super per acre per annum in the following ways: (1) 8 cwt. once in two years; (2) 4 cwt. once a year; (3) 2 cwt. twice a year; (4) 1J cwt. three times a year; (5) initial 4 cwt., plus 14 cwt., three times a year. This experiment has arrived at an interesting stage. Up to November, 1930, the experiment had been in progress for sixteen months, and the initial 8 cwt. dressing had maintained superiority. Since November, 1930, all other treatments are markedly superior to the 8 cwt. one, and up to the end of two years, when all plots except (5) will have had an equal amount of superphosphate, the superiority of the more frequently applied dressings is likely to be quite marked. (d) Study of Effect of applying Sulphate of Ammonia at Intervals of Two Months on Different Plots. (e) Trial to determine the Effect on Production of utilizing Herbage at 2 in. to 3 in. Stage and 4 in. to 5 in. Stage. (/) Trial to determine whether any Loss of Nitrogen occurs when Sulphate of Ammonia is mixed with Carbonate of Lime. The above trials are being conducted with much the same results as indicated in the last annual report. These trials, unlike (a), (b), and (c) above, are under a system of mowing only, with the result that considerable changes in the botanical make-up of the sward are evident. It is obvious that mowing only is not a satisfactory method of treatment of pasture if carried out over an extended period. CHEMICAL ANALYSIS OF HEBBAGE. Dry matter determinations are being made on all grass cut. As much chemical analysis as possible is being carried out," this work being done by Mr. Doak, Analytical Chemist, attached to this Station. EXTENSION OF WORK UNDER SYSTEM OF MOWING. As indicated in the last annual report, the mowing technique adopted is undoubtedly highly satisfactory for investigating certain problems. It is highly desirable to have this work extended, but until a special assistant to take full charge of the work at Marton is appointed it is inadvisable to proceed further. Further extension of this work to five or six stations, representative of different grassland districts of New Zealand, is highly desirable considering the importance of the grass crop to New Zealand. An area of about 10 acres at each centre should suffice for a start, but a special officer would require to be stationed at each centre. SHEEP-GRAZING TRIAL. This trial, which was commenced in August, 1928, has been continued, and should be carried on for another year. Very satisfactory control and utilization of pasture has been carried out during the past year, and the sheep have done extremely well under the system of intensive stocking. Sheep, which have been carried continuously for eighteen months under the system, produced at last shearing an average of 13-6 lb. of wool per head, and, judging by the appearance of the sheep at the present time, the wool-production at next shearing should be as good. During the calendar year 1929 the carrying-capacity over the year worked out at a little over ten sheep per acre. During 1930 the carrying-capacity worked out at 9-8 sheep per acre. Under a system of farming involving the raising and fattening of lambs this should allow for the carrying of seven to eight ewes per acre, the fattening of the lambs, and the conservation of hay and ensilage to meet stock requirements during low-production periods. As indicated in the last annual report, the information provided by this trial points to the desirability of acquiring farms specifically for the trial of a really intensive system of management accompanied by conservation of hay and ensilage. It should be pointed out that the pasture on which this trial has been conducted cannot be regarded as a really good one. The results are therefore more significant, as it is certain that even better results would obtain on good pasture.

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