SURVEYS OF SOILS.

New Zealand Herald, Volume LXVII, Issue 20649, 22 August 1930, Page 18

SURVEYS OF SOILS.

BY NITItOS.

ASSISTANCE TO FARMERS. IMPORTANT INVESTIGATIONS.

Although the New Zealand Research Department has had to reduce its estimates very considerably this year becauso of tho need for economy in Government administration, it is probable that the geological survey of areas in the Rotorua district and the King Country will go aliCr ul. If farmers throughout the Dominion fully understood the fundamental importance of this work it is probable that there would at once arise an insistent demand that it be pushed ahead with full speed, and economy practised in other departments, but that is beside the point in this article. It is true that a great deal of useful work has already been carried out in the areas under revie.w, but the fact remains that there are hundreds of thousands of acres either completely or partially out of production because of soil deficiencies. The proposed method of working is of interest and shows how necessary it is that these problems bo tackled from the right angle, and a start be made from the base. A preliminary survey of much of this country has shown that largo showers of volcanic ash have been distributed over parts of it, and it is suspected'that the troublo in portions of the Rotorua district is very similar to that existing in parts of tho King Country. How Science Helps.

Deficiency troubles in New Zealand havo gone loosely under the name of " bush sickness " among farmers, even where they are of very different type. In some cases it is possible to correct the deficiency by top-dressing, but in others tho administration of iron has been found necessary. A complete geological survey of tho whole area, including both tho portions affected and those in which stock remain healthy without special treatment, will show the essential differences between " sick " and clean land, and should bo a starting point in working out a solution of the troublo. Tho theory put forward tentatively is that different showers of volcanic ash havo been responsible for tho varying factors found in tho " sick " areas, and that bv mapping tho districts according to these showers it will be possible to say which parts correspond In this way it will bo found that the same type of treatment is needed at a number of widely scattered points, and that different treatment is needed elsewhere. It is a well-known fact among farmers in affected areas that a mixture of five parts of ground limestone to two of superphosphate will correct tho trouble in some cases, but that in others it is ineffective. The fundar mental work in tho geological survey should siiow why this is so, and will perhaps lead the way to new ideas in treatment or more economical methods. Fertiliser Problems. It can be stated as a fact that many thousands of pounds have been wasted by farmers in affected areas in the endeavour to correct the trouble. Naturally enough they have spared no effort to" make their land productive, and in the attempt, having nothing to guide them, they tested out all sorts of fertilisers. The work which is proposed is something similar to that which has been carried'out in tho Nelson district by the Cawthron Institute. Large areas of this district" have been carefully classified, the known facts being reduced to map form, showing essential differences in the class of soils Thus farmers are given definite information as to the class of treatment needed for their soils. Further work carried out year by year goes to show which are the most economical manures for them to use, and what methods result iu greatest profits per aero. It is no exaggeration to say that tho Cawthron Institute lias made farming much easier there, and the farmers themselves appreciate the fact, and are quick to apply to the institute for information. In exactly the same way, the work proposed in tho King Country and Rotorua areas will open up wide possibilities for the farmers in those areas, and should eventually result in information such as will lead to more profitable farming. It is work which cannot be hurried, which must take time to accomplish, but which should, in the long run, be worth many times its* cost.