FERN AND BLACKBERRY.

King Country Chronicle, Volume XXV, Issue 3263, 5 February 1931, Page 2

FERN AND BLACKBERRY.

EFFECTIVE CONTROL.

BUSH LAND FARMING.

Mr. A. G. Elliott, Instructor in Agriculture Fields Division, Blenheim, gives the following account of the system developed by Messrs. Harvey Brothers, at Manaroa, Pelorus Sound, for the control of fern and blackberry on hill country. The system may be held to apply to the Marlborough Sounds generally and to many other districts. The land held by the Harvey Brothers is roughly . 3500 acres in area and of this 1500 acres are still in standing bush, consisting of rimu, matai, tawa, hinau, and pukatea, with typical undergrowth, and carrying red beech (“brown birch”) on the harder ridges. Of the 2000 acres which were burned and surface-sown about 20 years ago, roughly 100 acres are ploughable, and comprise a fanshaped area fronting Pelorus Sound and into which the two main valleys open. The hill country rises to an elevation of about 2000 ft., and is made up of approximately equal areas of sunny and shady faces. It is on blocks of this country that the invasion of bracken hard-fern and water-fern with blackberry forced the farmers into the present method of control of this secondary growth. On two blocks, one of approximately 100 acres and another of 150 acres, both of sunny aspect, the bracken was a solid mass 4ft. in height, with large scattered clumps of blackberry through it, and with hard-fern well established in shaded places around stumps and beside logs. The average annual rainfall rate of the locality is approximately 63in. METHOD OF FARMING. At last shearing 2700 sheep were shorn on the property, and the average weight of fleece from these Romney crossbreds was 81b., while the average lambing percentage for the year was 90. All sheep were in good condition, and the prices for lambs were equal to the best in this part of the Sounds. A few head of cattle were run, but these are not important factors in secondary-growth control in this district, as will be shown. In 1910 an area of approximately 1800 acres, of which 500 acres were in surface-sown grass, was taken up and was then carrying 700 sheep. Bracken became established in the small valleys and gradually invaded the open areas, and to cope with this the old method of burning the fern and grazing it with sheep and cattle was tried, but without success. In order to carry the sheep the flats were ploughed and sown in permanent pasture, and more bush was felled. It was soon realised that control of secondary growth on the flats presented no great difficulty, but that some

better method of dealing with the hill country had to be evolved, as by this time the fern and blackberry had secured a good hold of those areas.

AN EFFECTIVE CLEARANCE. In 1914 a further block of 900 acres, of which 700 were felled and surfacesown and carrying 600 sheep, was taken up, with a result that that year the farmers had 1300 sheep averaging a 61b. fleece with a lambing percentage of 87. During the next ten years burning-off of fei:n and blackberry, accompanied by a small amount of surface-sowing was continued with but little success, Whole blocks which formerly carried one sheep per acre were at the end of ten years producing nothing but secondary growth. In 1924 a reverted block of 35 acres of shady face was tackled; the heaviest blackberry clumps were chopped down, and the whole burned off during the first week in March. The area was then surface-sown with a mixture of perennial ryegrass, crested dogstail, brown-top, and white clover. During the winter it was lightly stocked with one sheep per acre, but during the summer carried three sheep per acre, and now does this regularly. At present the constituents of the pasture ai'e brown-top, crested dogstail, white clover, sucklingclover and Yorkshire fog, with winged thistle and hydrocotyle in patches. The only traces of fern are in places inaccessible to sheep under the edges of logs and there has been quite an effective clearance of blackberry. On all these areas the actual con trol of the young fern on the burn is done by hoggets, which are brought in when required and sold forward. For the last three years they have been disposed of at a profit of 2/- per head, but it is obvious that their real value lies in secondary-growth control. The cattle merely have access to the blocks during the winter, but are not shut in on any of the areas as a definite factor in dealing with fern and blackberry. MAIN POINTS SUMMARISED. The main points in the system practised by the Harvey Brothers are as follows: (1) Allow’ secondary growth to get away for at least three or four years, so that a good burn may be secured. By this time the soil is opened up by the fern-roots, and with the ash secured from the burn a good seedbed results. At Manaroa burning is done during the first two weeks in March.

(2) Cut all large bushes of blackberry to allow sheep to get among the burnt sticks to graze on young shoots and surface-sown grass. The cost of blackberry cutting is approximately £2 10s per acre.

(3) Sow' up to 121 b. per acre of a grass mixture consisting of cocksfoot danthonia, Chewings fescue, perennial ryegrass, crested dogstail, and white clover.

(4) Depending on the season, graze lightly with hoggets about two months after sowing and increase the stocking until the growth is held. Grasses are not allowed to seed and the young fern and blackberry is nipped off early. The average spring and summer stocking at Manaroa is three and a half sheep per acre up to the end of February. Bought-in hoggets are held on the new blocks and remain there through the winter.

(5) The cheapness of the method is obvious, as country originally carrying one sheep per acre and later reverting to fern can in two years, with an expenditure of 8/- per acre for seed, to which should be added 2/per acre for sowing, be brought back so that it can do two sheep per acre well. The bought-in hoggets used solely for secondary-growth control, are sold at a profit. (6) The method has proved successful for handling fern and blackberry on both sunny and shady faces. Sheep will not eat either the hardfern or water-fern, but at Manaroa so far such good burns have been secured that the recurrence of these growths has not proved a problem. The water-fern disappears when its shelter is burned off, and if the hardup fern reappears it can be dealt with by piling rubbish on it and burning it off with a hot fire. Such areas will again be surface-sown with the mixture already specified.