TOP-DRESSING OF PASTURES.

Horowhenua Chronicle, 23 September 1927, Page 7

TOP-DRESSING OF PASTURES.

VISIT TO EXPERIMENTAL PLOTS.

DEMONSTRATION BY GOVERN-

MENT INSTRUCTOR

Under the auspices of the Levin branch of the New Zealand Farmers' Union, a well-attended gathering of farmers spent an interesting and instructive time on Wednesday afternoon, inspecting on Mr A. J. Gimblett's farm, Gladstone road, an area top-dressed under the supervision of the officers of the .Fields Division of the Department of Agriculture, for the purpose of demonstrating the action of the most important phosphatic Settilisors PHOSPHATE DEFICIENCY.

Mr R. P. Council, M.A., instructor in Agriculture in charge of the Wellington and Southern Hawkes Bay district, explained the general plan of the experiments. He pointed out that the demonstration was confined to phosphatic fertilisers because at the present juncture the proper use of phosphatic fertilisers was the most important fertiliser problem which farmers had to solve. This arose from the fact that New Zealand soils in general were originally poorly supplied with phosphates, and the original poor supply of phosphates continuously was being depleted further by farming, whether it be dairying or stock raising. INTRODUCTION OF NITROGEN. In addition it was recognised that the fertility of many soils would be improved by an increase in the soil content of nitrogen. In this connection phosphates were of great indirect importance because in pastures they stimulated the growth and increased the vigour of the clovers. Clovers acted, in a manner which was mutually advantageous, with certain tiny soil organisms which had the power of drawing nitrogen from the plentiful atmospheric supply and thereby increasing the soil supply of nitrogen. Against this it must be remembered that other crops not belonging to the plant family to which the clovers belonged depleted rather than increased the soil supply of nitrogen. The extent to which the clovers improved the soil supply of nitrogen had not been measured carefully in New Zealand, but a South of England experience was available in which the residues of a red clover crop saved for hay increased the nitrogen supply of the soil by 3001 b per acre. To bring about this increase in New Zealand, by the use of artificial nitrogenous fertilisers would require an expenditure of over £8 an acre. Hence the use of phosphates has an important indirect bearing on soil fertility. Because of all this, phosphates have ..a dominant place in New Zealand fertiliser consideration. PRACTICAL EXAMPLES.

On Mr Gimblett's farm, adjoining pasture strips six chains long and eight feet wide have been top-dressed with superphosphate, basic slag, basic superphosphate, and Ephos respectively. The top-dressing was applied at the rate of 3 cwt. per acre. The dressings of the above-named fertilisers were repeated six times and the repetitions were separated from each other bv control strips to which no manure has been applied. The object of repeating the dressings six times in adjacent plots was to minimise the influence of soil variations. The area under consideration had been top-dressed in the first instance on June 2drd, 1926, Certain strips were top-dressed again during May, 1927, and these lie quite close to the ones which were top-dresa-ed only once and that in June, 1926. SUPERPHOSPHATE GIVES MOST BENEFIT. The farmers in attendance were invited to pass- judgment on the plots without knowing what manures had been applied to the areas, which they were called upon to compare. Practically general agreement was come to on the following points: —

(1) All the fertilisers used had a markedly beneficial effect on the pastures, this being especially noticeable in respect to the clover growth. (2) On the areas which had been topdressed twice (i.e., in June, 1926, and again in May, 1927) the plots to which superphosphate had been applied were generally selected as the ones carrying the best pastures. The other dressings all had markedly beneficial effects, but there was no general agreement as to the relative influence, of the various materials. (3) On the areas wMch had been top-dressed only once, in June, 1926, superphosphate was again generally, selected as giving the best results. This was most significant because of an impression, which is quite general, to the effect that the influence of superphosphate extends over only one season. USE OF LIME. Limed plots were compared with adjacent unlimed plots. The lime had been applied at the rate of one ton of carbonate per acre, in June, 1926. Without knowing where the lime had been applied, many of those present picked the limed area as the one carrying the better pasture covering. Though no marked differences could be observed many were inclined to the opinion that liming had increased the beneficial effect of superphosphate and decreased that of Ephos, while no opinion was expressed in respect to the other manures used. GENEEAL EFFECTS OF FEETILISERS. Apart from the area under the supervision of the Department of Agriculture attention was given to other fields on Mr Gimblett'g property, which demonstrated in a striking manner the beneficial influence of the liberal use of fertilisers on pasture extending over a period of years. Again on Mr F. E. Wright's property marked benefits from top-dressing were noted on a fourteen-year-old pasture. Thanks were fittingly accorded Mrs Wright for her hospitality in dispensing afternoon tea. -