SOILS AND PASTURE

Evening Post, Volume CXVI, Issue 19, 22 July 1933, Page 15

SOILS AND PASTURE

PROGRESS IN RESEARCH

THE CAWTHRON INSTITUTE

'' Some Recent Researches i" Agricultural Science" was tho subject of a lecture to the Nelson Philosophical Society by Mr. T. lligg, of the Cawthron Institute.

In his introductory remarks Mr. Rigg stated that many notablo advances had been made- in different branches of agricultural science during tho last five years. For tho purpose of his lecture lie had chosen certain subjects dealing with soils, pastures, and stock health which had been investigated in great detail in many parts Of the British Empire, and in which considerable progress had been made in New Zealand by workers attached to tho Cawthron Institute and to different Government departments. As a result of tho work inaugurated by the Department of Scientific and Industrial Research in co-operation with tho Cawthron Institute, groat progress had been mado in the classification and mapping of the volcanic soils of the North Island, continued tho speaker. Tho identification and mapping of tho eight principal soil-forming volcanic ash showers covering the central part of tho.North Island must bo recognised as a valuable contribution towards the development of agrieulturo in tho Central North Island territory. The soil map which is nowavailable concerning the distribution of tho volcanic ash showers is providing much valuable information concerning difficulties likely to be experienced; iv opening up land, and afc the same time forms a basis for fertiliser studies, and the investigation of many problems connected with tho dairy and sheep industries of the territory.

TARANAKI DEPOSITS,

During the past season Messrs.'L. I. Grange- and N. H. Taylor1, of the Geological Survey, have extended the field mapping of volcanic soils to the Taranaki district. They havo been able to identify three main ash showers from Mount Egmont, which cover large areas of TarauakL The laboratory examinations made at the Cawthron Institute on soil samples collected from typical areas located on these three volcanic ash showers indicate marked differences in the texture of the three groups of soils.. The chemical analyses havo shown that the majority of Taranaki soils are exceedingly well supplied with available phosphate, but considerable variation occurs in the amount of available potash. Taranaki soils as a whole have a comparatively high P.H. value, and in comparison with many other soils aro well-supplied with lime. As a result of the success which attended tho Hohenhcim system of pasture management in Germany during the war, much attention had- been directed by scientists throughout the world to intensive studies dealing with the value of pasture grass and its management, said Mr. Bigg. In the United Kingdom, Woodman, Staplcdon, and On- have made very important contributions to our knowledge of tho feeding value of pasture grasses in tho young growth stage, the value of different strains of grasses and clovers, and tho importance of an adequate-, mineral supply in pasture grass in tho maintenance of stock health.

The work done at the Cawthrou Institute had confirmed the conclusions of Woodman that pasture grass grazed at the young growth stago lias a high feeding value, equal approximately to linseed cake, and that in its content of protein, pastures grazed at the young growth stage supply moro of this important constituent than the much higher yielding hay and aftermath: crop's, investigations in New Zealand have- shown -the striking effect of climate in controlling both yield and chemical composition of pasture- grass. In periods of. drought, marked reduction in 1 the soluble ash, nitrogen, and phosphoric-acid contents invariably occur.

THE LACK OF IRON.,

After dealing with iron in relation to tho health of stock, Mr. Rigg said that in previous investigations dealing with the occurrence and cause of bushsickneas in New Zealuud, workers at the Ca,wthron Institute suggested that stock derived part of their food iron from the iron compounds of the soil, and that tho amount and availability of iron in the. soil determined to a large extent tho incidence or otherwise of bush-sickness in certain areas of New Zealandi In order to secure confirmation .concerning, the possible value of soil in overcoming bush-sickness, a drench consisting of a suspension in water of a Nelson soil, had been given twice a week to sheep grazing bush-sick pastures at Glenhope. Tho sheep receiving tho soil drench havo done remarkably well, have shown no. symptoms of bush-sickness, and are in excellent condition. The control sheep grazing the same pasture became badly affected with bush-sickness during the autumn; several deaths had occurred, and those remaining were in poor condition. Both groups of sheep grazed the same- pasture, tho only difference being a supplement of soil in one case and not in the other.

Although no explanation could be offered at tho present time of tho success which had been obtained on the ono hand with Nelson soil and the failure on the other hand with limonite ore from Onekaka in overcoming bushsiekness, the results clearly indicated tho beneficial effect Of certain soils in overcoming ailment of the bush-sick-ness type. Tho result obtained had a •wide significance in. relation to stock health throughout New Zealand, and indeed throughout the world, and pointed clearly to tho necessity for a careful study of soils in their relation to stock health.