PASTURE FURROW TRIAL

Press, Volume LXXXVI, Issue 26129, 3 June 1950, Page 5

PASTURE FURROW TRIAL

CONSERVING WATER ON SLOPES GEBBIE’S VALLEY FARM Pasture furrowing is being tried, for the first time on a commercial farm in Canterbury, on a hill face on a farm in Gebbie’s Valley. Pasture furrowing, a system of conserving moisture on slopes, has been successful in Australia and the United States, and has given good promise experimentally in Marlborough and in South Canterbury. Pasture furrowing consists, briefly, of running furrows along the contour of a slope to form troughs which collect the moisture running down the slope. The troughs hold water and release it slowly down the slope. They are shallow, and grassed over, and do not interfere with the grazing of the slope. They assist in controlling sheet and gully erosion, but their most important function is to conserve moisi ture and make possible a better growth lof grass in situations where the soil I dries out rapidly under a quick run-off I of moisture. i The farm lies partly on the flats in ! the valley, and partly on the hills. The i flats lie very wet in some seasons, but I are heavy and highly productive land. i The soil on the hill faces is a good I loam, and of good depth, but the faces | are steep, and in the 27in rainfall and I prevailing north easterly wind, they i dry out badly and good pasture alternates with a thin covering into which danthonia and other less productive • species work their way. The paddock of 24 acres which has been furrowed lies so that the wind through Gebbies Pass sweeps along it. It has been down for at least 50 years, and in good conditions carries a good pasture- of ryegrass, white clover, and some cocksfoot and dogstail. After dry seasons it has been necessary to surface sow the thinner patches, but the plants thus established are liable to die out in the next dry period. The general slope is 20 degrees, but it is of course uneven, and parts run up to 33 degrees. On the flatter pieces, grass is thick and holds well, and in

some places there are even patches of rushes. , Plough Tilled Furrowing was done with a Ferguson tractor with two-furrow plough attached direct. The plough was set at a tilt so that the outside share cut a thin wedge with a base about 3in deep, on which the inside mouldboard laid another wedge-shaped slice about 6in thick at the base. It is of interest that the soil below about three inches down was bone dry when the work was done a fortnight ago. There was some slight difficulty with the furrows being pushed too far down the slope in some places, but this could no doubt be overcome with a shorter mouldboard. The tractor wheels were set as i far apart as possible, but on the steeper parts, particularly where there was thick growth, the tractor was inclined to slide sideways down the slope and some time was lost in consequence. Some form of bower wheel for the main wheels and anti-skid bands for the front wheels would overcome this. The furrows were drawn an average of 20 feet apart. On the steepest parts of the slope, they are about 15 feet apart, and on easier parts they widen out considerably. Every chain or so along the furrow, the plough was lifted for about a yard to make a block which would prevent the water from running out from the whole furrow in the event of damage to one part of it. An untreated control strip has been left down the middle of the slope. Six men worked on the job and completed the 24 acres in 10 hours. Four of the six were engaged in laying out the levels along the slope, one in driving the tractor, and one in pulling out the pins put in along the contours to guide the tractor. Levelling was done with a device developed by the College, and the four men were just able to keep ahead of the tractor. In the ordinary way. two men could handle the whole operation of levelling and Ploughing, but it would, of course, take longer. The college is at present developing a levelling device which will fit to the tractor, and save a great deal of time now used up in preliminary work. No precise record of costs was kept, but the Soil Conservation Council has found that similar work costs about 6s an acre, of which 3s is represented by surveying costs when surveying is done by trained men. Costs could be cut to about 3s with the levelling device fitted to the tractor. Great interest will attach to this trial of pasture furrowing. If it is successful at Gebbies Valley, it could be apnlied on large areas of low rainfall hill land in Canterbury as well as extensive areas on the Peninsula. The work has been done with the assistance of Lincoln College and the Soil Conservation Council.