SOIL SURVEY

Press, Volume LXXXIII, Issue 25270, 23 August 1947, Page 6

SOIL SURVEY

PROGRESS WITH NEW MAP

VALUE OF WORK DESCRIBED All but a week’s field work for a soil map of the plains and ploughable downs area between Herbert in the south and Waipara in the north, had been completed, but there was months of office work and drafting to be done before the project was ready for the printers, said the officer in charge of the Soil Survey, branch of the Department of Scientific and Industrial Research at Christchurch (Mr C. S. Harris), in an interview.

In answer to a question on the genvalue of soil survey work, Mr Hariris said that the information collected had many uses and could form a valuable basis for other investigations. Top-dressing, manuring, pasture mixture, and other trials could be related to the type of soil on which they were laid down, and from them the best practice for that soil type determined. For example, a trial on a particular soil type might indicate a need for potash. A similar need could therefore be expected wherever that soil type occurred.

Similar trials, he said, could be laid down to assess the suitability of the different soil types in the district for the growing of crops, or with which local farmers were not familiar. Tobacco, linen flax, and sugar beet were examples. Engineers in planning an irrigation scheme needed to know in advance how much and where water would be needed. With the aid of a soil map this could be rapidly determined for it was a simple matter to measure the optimum water content for each soil type mapped in the area. In fact, most land development and large-scale construction schemes could make extensive use of soil maps. Value of the Work “The following examples illustrate the nature and value of soil surveys,” said Mr Harris. “A reconnaissance -survey of the North Island on a scale of four mil 5s to the inch has been completed and from that soil map it has been possible to prepare: (a) a simplified map showing lime requirements and responses; (b) a simplified map of she North Island soils grouped into six major fertility classes; (c) a map of the southern and eastern portion of the island showing the occurrence and severity of erosion. Further maps will follow.

“Officers of the Department of Scientific and Industrial Research have prepared a detailed soil survey of the Whangarei County, and with the aid of this Dr. W. Hamilton, an economist in the same department, has prepared a painstaking statistical farm management survey,” Mr Harris said. A soil survey of the Ashburton County in 1935 has been a valuable aid in the planning of the irrigation scheme. Also a farm management survey and report, based on this map, was prepared by Mr J. Fleming working under the direction of Dr. I. W. Weston, of Lincoln College.

“A one mile to the inch map of the western slopes of Akaroa harbour was prepared at the request of the Farmers’ Union as they considered the area to be representative of the whole peninsula. Since this map was made the Department of Agriculture has laid down further top-dressing trials on some of the main types shown.” During the war a reconnaissance survey of all the high country from Blenheim to Lake Wakatipu had been completed, said Mr Harris. Showing the degree of soil erosion and soil types in the high country, it was published on a scale of eight miles to the inch as a bulletin by the Department of Scientific and Industrial Research. This job was planned to provide a general picture of soil and erosion conditions in the high country for such bodies as the catchment boards, then being set up. Making Soil Maps

In making a soil map the first essential was to establish the nature of the various soils occurring the district, Mr Harris said. Numerous factors went to make up a soil, including whether it was a sand, a loam or a clay, its age, its slope if on rolling country, and whether or not moisture was normally present. After noting these various properties it was possible to get a good advance idea as to what a chemical analysis would disclose. Mapping of a new area was done in stages. First a general picture of the soils was prepared on a four mile to the inch map. In *this survey note was taken only of pronounced differences in texture, age, and degree of wetness. Boundaries were plotted approximately and a few samples taken from typical soils for chemical analysis. This map was followed up by more detailed work on the scale of one mile to one inch. For particular reasons where more detailed work still was required, special surveys might be made on scales 20 or 10 chains to the inch. “First of all we map the soils on field Characteristics and when this work is finished for any particular area, we go out with the map in hand and collect samples from typical areas of soil types for chemical analysis. These chemical and other analyses give additional information to that found in the field,” said Mr Harris. “Although we might suspect that certain rivers bring down different soil forming materials from their catchment areas, there may be no clear field evidence for this. In such a case chemistry can be a great help in settling problems.” MR W. J. CROUCHER The pig industry in New Zealand has reached Its present state of efficiency largely because of the efforts in earlier days of Mr W. J. Croucher, who died recently in Palmerston North. He worked for some years as a journalist in the Manawatu, where, of course, he came into close contact with the dairying industry. He was much impressed with the great waste of buttermilk from the factories, and set out to devise a system for converting this waste into pig meat. At that time the bacon curers had a pretty firm grip on the market for farmers’ pigs, and it was necessary to organise a cooperative system of selling pigs. Mr Croucher, after a good deal of difficulty got a co-operative movement going so successfully that the hold of the curers was broken, with resulting profit to pig fatteners. He was among the first men to study the possibilities of growth in relation to weight to practical account, and adopted the then unusual practice of buying pigs by weight. He was a foundation member of the Manawatu Orua Pig Recording Club, which was the first effective organisation of its kind. The effect of the pig clubs in raising the standard of New Zealand pig breeding and management has been nothing short of revolutionary. He was a pig farmer himself, but came into contact with the general public mostly through his activities as recording officer for the pig club he helped to found. He could be found at most North Island shows tactfully spreading the gospel, and his scales, and his talks on feeding earned him the nick-name of “Plunket Bill,” by which he was generally known throughout the North Island. His recording work brought together a most important mass of details which indicated the lines on which pig farmers are still working. He was the author of “My Friend the Pig,” which is still the best work on the subject.

Rents of land on the island of Guernsey are the highest in Europe. Rents average about £2O an acre a year. The price of this land averages about £6OO an acre.