H.— 34,

24

(6) Lightness of the bones of dead animals. Although the bones are light, there are no cases where bone-lesions have been observed, such as occur in phosphate-deficient areas in cattle ; neither do the bones break easily, as has been found in sheep in an osseous cachexia case (Reid and Aston, reported in N.Z Journal of Agriculture, 15th November, 1910, page 422). The writer regards this absence of bone-lesions as confirmatory evidence of calcium deficiency, as Theiler was unable to produce bone-malnutrition by deficient calcium diet, only general emaciation. (7) Botanical composition of pastures showing moss, Danthonia, Yorkshire fog, and browntop (Agrostis)—species that love sour soils. (8) Preference of sheep for limes over unlimed pasture. (9) The fact that the land after a forest-burn was highly productive, but after some years deteriorated rapidly, indicated that something was being leached out of the soil, assisted by the heavy rainfall of this upland locality, that had been contributed by the ashes of the bush-burn. The only element which could answer to this description was calcium. Phosphates are not leached out of the soil. Work during the year has been largely concentrated in the field experiments. Mr. C. M. Wright, a farmer with chemical training, and an assistant, also a farmer, have been busily engaged in supervising extensive trials with various top-dressings on pasture on which sheep were used to determine the effect of the dressings in ameliorating the malnutrition. The results of the year's work have confirmed the first prediction, that calcium is the deficient element, or, to put it in Mr. Wright's words, " lime is the limiting factor " in farming these King-country volcanic loams, and it would seem that a mixture of 5 cwt. of ground limestone and 2 cwt. of superphosphate, which would supply 12 parts of calcium to 1 part of phosphorus, is likely to be a dressing which will enable the settlers to overcome their present difficulties. One may say that the farming community of the districts in which the experiments have been carried out seem to be convinced of the correctness of the conclusion that some form of calcium is necessary to bring the land back to its former productiveness. The local officers of the Chemistry Section of the Department have had the whole-hearted support of the settlers. The two lime companies operating in the district—Wilsons' Lime Co. and the Hangatiki Lime Co. —have supplied a very large quantity of lime (50 tons each) at cost price, and the Challenge Phosphate Co., of Auckland, has donated a truck of superphosphate. The Australian companies have given or promised to give consignments of some tons of gypsum (sulphate of lime), and the Golden Bay Cement Co. and the Milburn Lime and Cement Co. have also enabled the Department to obtain gypsum from their stores. That the rehabilitation of this fine type of country, now classed as " deteriorated," is now only a matter of time and the granting of reasonable financial facilities, is the opinion of the writer.

Summary of Mairoa Experiments.

Area. Treatment. Grazing. Pastures. Results. 20 2 tons ground limestone, 40 cull hoggets, Feb., Originally tawa-rimu; Sheep have done well. Jan., 1928 1928, and cattle grassed twenty years--run-out Danthonia and Lotus major ; now much healthier and clover showing 5 4 cwt. gypsum, Oct., 1928 8 hoggets, 3 cows and Improved in appearance ! Sheep satisfactory ; weight calves, Nov., 1928 increased. 7 Control .. 10 hoggets, Nov., 1928 .. .. ! Sheep holding their own. 35 Field divided in two ; No. 38 ewes and 1 ram, Mar., 21 CaC0 3 pellets used 1929 10 14 tons limestone, Jan., 11 cull ewes .. .. .. ! Ewes did well—7 lambs; 1928 j also night paddock for cows. 20 5 cwt. limestone and 2 cwt. April, 1928, heavily Better soil than elsewhere; No grazing records kept, super., April, 1928 stocked with cattle heavy fern crushed out and sheep by top-dressing in fern 11 5 cwt. limestone and 2 cwt. 11 sheep, mixed sexes .. Originally ferr)-manuka Now possible rear young super., May, 1928 and now greatly im- sheep. One strip limed proved only neglected by stock. 10 1 ton limestone, Jan, 1928 ; No records kept; owner Originally fern-manuka, No grazing on area where 2 cwt. basic super., Aug., considers lime - phos- but grassed fifteen i basic super, not used. 1928 phate dressing suitable years; badly run out j 13 2 tons limestone, Mar., 1928; No records kept .. Twelve-year-old pasture Stock doing better after 2 cwt. super., spring, 1928 liberally phosphated I lime treatment. without result; improved in appearance I Waitangururu. 20 5-2 limestone-super, June, j 20cows, 18ewes, 16lambs Originally tawa-rimu Previous great trouble 1928 ! bush, grassed eighteen with sheep now years averted ; lambs ceased dying from malnutrition and now killed fat. Ngapaenga. 4\ 5-2 limestone-super, Aug., . Seven-year-old run-out I Now available to improve 5 / 1928 j pasture; now improved cull sheep.