CARE OF PASTURES.

New Zealand Herald, Volume LXV, Issue 20092, 1 November 1928, Page 5

CARE OF PASTURES.

DETERIORATED AREAS

A KING COUNTRY PROBLEM

THE DEFICIENCY OF LIME

iln pioneering :i new couiiiry ii is com |)ar;ilivelv easy for farmers to take advan I tagc of l lie work of nature ui accumulat- | ing stores of fertility in the soil and in the I past New Zealandeis have had singularly ' ' little trouble in making pastures wlicr«s , once forests grew in dense luxuriance and I formed an earth covering rich m humus ! and mineral elements prepared for plant food by the decomposition of leaves and • other .vegetable masses. Even m the | burning of the forests there is deposited on the surface, ready for use by pasture plants from halt u ton to two tons of wood ashes per aire, an excellent top--1 dressing, worth more than the average 1 tanner puts on to Ins pastures in the shape ; of artificial fertilisers. 1 If it had not been for this fact the ' Dominion to day would not possess as I i does, nearly 1^,000,000 acres of man-made ; pastures, famous throughout the world for i their productiveness and giving to the ; nation its greatest source ot wealth n: the shape o! wool, meat and dairy produce. The Sources of Fertility. J'lie sources of natural fertility, even 1 in the richest soils and where nature aci cumulated her greatest stores of plant ! food, are not inexhaustablu, and the supply ' of wood ashes from the heaviest bush burns comes to an end sooner or later. I It is estimated that the most luxuriant ! pastures lormed by surface sowing begins ■to deteriorate after ten years. Not only | arc the supplies oi nitrogen, potash, plios- , phates ana other mineral elements drawn ! upon heavily by constant stocking which means the production in the course of ' years of tons ot meat and hone anil milk, I and wool, but it is certain also that even : what are called perennia.l grasses exhaust I themselves gradually and have only a ■ limited life cycle. iliese tacts are obvious : to any thinking man who ts a student ! of agriculture, but the fact remains that j tiie average settler who has put his labour into the formation of pasture on bush j lands is rarely aware of the change in time | to remedy the deficiency, and in some I cases the deficiency may be only due to | the exhaustion of perhaps one or two | minor or major elements. The Chemistry Division of the New Zea- : land Agricultural Department, under the ! able direction of Mr. B. C. Aston, has, | during the past decade, done invaluable ! work for farmers in demonstrating first, j by soil analyses and secondly, by test exI periments, what elements of fertility are ; lacking in certain of our deteriorated soils. I and have in nearly every case shown how 1 those missing elements can be economically j supplied. Its work on the pumice soils in the central districts of the North Island has helped the settler there to overcome, the so-called stock-sick trouble, and may : be said to have added to the country's resources vast areas hitherto considered 1 unsuitable for farming. Work of the Soil Chemist,. Recently the officers of the Chemistry ; Division have been at work on the de- | ; tenorated pastoral country to the westward ! of the Main Trunk line from Te Kuiti and Otorohanga, and their work has revealed the remarkable fact that in a region j noted for its outcrops of high-class lime stone, deficiency of lime is one of the | chief causes of the deterioration of pasture ) and its diminishing quality as a food for slock. Without the aid of ihe soilchemist such a discovery could never ha\;o | been made not • would such a simple i solution of the problem been possible. Mr. B. C. Aston, in his report on this • work says:—"ln August 1926, the writer : vvas first consulted regarding a type of soil occuring about 15 miles west of To I Kuiti. The first inquiry related to thu ! soil itself," which had ceased to produce | the same good quality of sheep-pasture ! that in the past had given this district an excellent name as a fertile country in the years immediately following the ' burn'—the operation of " bringing in " the. bush-country, or in other words, of quickly converting forest-land to a sheep and cattle grazing pasture. It appeared upon investigation that land for which £l7 an acre was refused previous to the war was now unsaleable even at i one-third of that price, and that some j farms had changed hands at. something j like £2 an acre, a prire which included | dwelling and other buildings and aM other j improvements. Such rapid and great deI lerioration in the market-value could not. ! be for the greater part attributed to falling prices. History of the Settlement. " The history of this settlement relates that for the first seven or eight years after the burn the pasture carried 1A ewes to the acre and the lambs did well on ii, but after this the pasture deteriorated very rapidly; the so-called English good grasses disappeared, and the carrying capacity fell below one dry sheep to the acre, and even with this diminished stocking the auimals did not thrive. The extraordinary tiling was that the usual ; remedy for deteriorated land, viz.. top- ; dressing with phosphates, although it imi proved I lie summer carrying capacity did I not effect the improvement hoped for in j the returns. I "The pasture on land that had been { top-dressed with basic slag, superphosJ phate, and potash manures (Bcwt. in four | years) was still apparently deficient in j some ingredient. In summer the top- ; dressed pasture looked well and grew i ! lot of good grass, but iu winter the ground j became full of moss which disappeared in j Ihe summer The number of culls in the I llock was unusually high, although when ' these were taken to land where no deterioration bad set in they fattened and > often became the best sheep in their new | home. ! " Chemical analysis of the composite soil showed no deficiency of any of the. three valuable ingredients of fertilisers, the available potash being very high, and ! phosphoric acid being hieh, while 'lhe : total nitrogen was particularly high. Some j deficiency of the mineral food was mis i pec ted. especially as on examination the | bones of sheep which had died were j found to lie unusually fragile and light." Result of Analyses. Chemical soil analyses showed a remarkable deficiency in lime content, amounting to as much as ten tons to the ! acre and a careful examination has demonstrated that this lime deficiency is Ihe chief cause of pasture and stock troubles. Jn places where pastures have been dressed j even with small quantities oi lime With grass and stock have shown remarkable improvement, and it seems almost definitely proved, even alter a comparatively short period of tests that the application of lime is the solution of the trouble which has seriouslv affected large arens of : otherwise extremely valuable land in "his part, of the, Dominion. This very gratifying result is a decided triumph for the soil chemist, almost as ■ important 'r its way as Ihe discover.' h_v the same otVirers that iron deficiency was the chief cause " r Mie Mairaku stork sickness Ibe Agricultural Depai t went • is to be ninjia!ulaled on its success in •bis directirn. -Mid since limestone is alum dant in f he HTected districts, and can lie made cheaply availab'e bv- grinding '> burning it mav he confidently anticina'ed 'hat great areas of beautifully shaped •nifl naturallv rich King Country lands, which have been under a cloud of doubt j and suspicion for some years, will be once j more brought back to their old state of I productivity and prosperity.