SOIL EROSION

New Zealand Herald, Volume LXXV, Issue 23228, 23 December 1938, Page 4

SOIL EROSION

CAUSES OF WASTAGE BURNING NATIVE PLANTS OVERSTOCKING .A FACTOR BY OUIDIRE Soil erosion is a "burning" matter in many countries to-day, and in this .Dominion tho soil wastage from this causo is largely credited to tho overcommon practice of burning tho native grasses and plants at frequent intervals to promote green growth or get rid of inferior plants such as scrub or fern. This is believed to destroy tho humus and bacterial lifo in the immediate surface soil and reduco it to a powdery condition in which it readily washes or is blown away. Another factor which probably plays a most important part in promoting soil erosion is over-stocking. Attention is boing given to this phase in South Africa, in that country soil erosion appeara to he principally brought about by over-grazing the veldt. The poor, dry and bare state of the ground following over-stocking does not encourago tho absorption of tho heavy rains when they occur. Tho result is that the top-soil is simply washed away. Jn South Africa methods are being devised to prevent over-stocking, and these largely depend upon tho farming of tho land by people who have a knowledge of safe intensive fanning methods or who are under tho direct supervision of officials who do know. When soil erosion is comprehensively studied in New Zealand it is almost certain that both tho stocking of the hill pastures and their burning will havo to ho brought under the strictest compulsory control. Thousands of acres of tussock land in the South Island, once carrying many sheep, havo been converted to shifting shinglo slides by these twin evils, and much of our better second and third-class land in both islands is fast approaching tho samo useless state.