SWAMP RECLAMATION

Press, Volume CV, Issue 30971, 29 January 1966, Page 8

SWAMP RECLAMATION

The draining- and development of potentially fertile flats in the Grays Hills and Grampian station areas in the Mackenzie Country were described to high country runholders from all parts of the South Island who attended a field day on stations along the Haldon road last week.

Mr E. R. L. O’Toole, resident engineer of the Ministry of Works at Timaru, said that the flats were estimated to comprise about 26,000 acres and a considerable area of this valuable land had been in swamp. The area could be described as being about 10 miles long by about a mile wide. A few years ago, he said, the area of swamp had been increasing. The Grays river, with no physical feature confining its channel, had followed a meandering pattern.

A £2 for £1 subsidy had been approved on the initial scheme costing £5400 put up to the Soil Conservation and, Rivers Control Council in 1959. The first part of the work had involved the removal of willows in the lower parts of the river and also obstructions in the higher parts of the river. The second stage had involved improving the channel of the river by removing the meanders.

With the water table dropping the runholders had been impressed with what had

been done and a second programme had been proposed costing £3OOO and also bearing a£2 for £1 subsidy. It involved lateral channels to tap streams and springs. The final stage of the reclamation programme, which had not yet been reached, was further willow clearing and poisoning as some of the trees already poisoned were growing again, so that there was now a need for a followup programme and continuing maintenance to preserve what had been done.

Mr O’Toole put the total cost of these works at about £lO.OOO.

The development of about 1000 acres of swamp country on the Grampians station was described by Mr R. M. McNeilly, the manager of the station.

In the early 1950 s he said that this area was carrying 50 to 100 head of cattle for about three months a year and Merino sheep were grazing on it on and off all the year round, although this was not very economic on account of the death rate in the bogs. The drainage and development scheme had begun about 1953 when a subsidy for about a third of a £2OOO scheme had been obtained through the Waitaki Catchment Commission. This had enabled drains to be opened and stop banks to be built. This had enabled cultivation to begin and in the last 13 years 320 acres had been ploughed and sown down to pasture and . about 150 acres had been oversown.

Where the country had been sown the pasture mixture had comprised about 201 b of ryegrass, 51b of timothy, 51b of montgomery red clover, and 41b of white clover with 2cwt of superphosphate, and maintenance dress-

ings had since consisted of lewt alternately of sulphur superphosphate and ordinary superphosphate. The oversowing had been done with 3cwt of sulphur super and 91b of clover to the acre followed by 3cwt of sulphur super in the following year and thereafter maintenance dressings of lewt to Ijcwt of ordinary superphosphate. The cattle population on the former swamp area had increased from practically none until today there were 320 breeding cows, 300 calves. 40 replacement heifers, and 200 bullocks for fattening.

The young stock were wintered nearby and fed hay—last year about 6000 bales were fed to the bullocks and replacement heifers and baled wheat and oat straw to the cows. Heavy hay crops of the order of 100 bales to the acre had been taken off one paddock and two crops of oats of about the 100 bushels to the acre mark had been taken off the drier area. The oats had been threshed with a mill and the cattle had subsequently eaten very bit of the straw that had been stacked. Last year 150 fat bullocks, 75 fat vealers, and 90 calves had been put off this area, and without calves this amounted to production of 1321 b of fat beef to the acre. In addition the area had been carrying the complete herd. The cost of the development of this area including drainage, cultivation, fencing and sowing was put down at about £25 an acre, said Mr McNeilly. Some 200 acres of heavy water-logged country had yet to be drained and it was hoped that the station might receive some outside assistance in this respect. At a later stage in the day Mr McNeilly described development of the Whalesback part of the Grampians, an area at about 2000 ft with a rainfall of about 24 inches. Prior to starting this programme in 1960 he said it was carrying about one sheep to three acres but now with pasture and lucerne it had this seastm carried five ewes and their lambs to the acre.

Some of this country had [been broken up 30 years earlier and sown in fescue, he said. In the current programme the general practice had been to sow two crops of oats before going into pasture or lucerne. On one block only one oat crop had been used but it was found that, this did not break up the ground sufficiently. The first oat crop yielded about 35 bushels to the acre and the second about 50 bushels. The costs involved in the first crop including fencing were slightly more than the return but there was a credit balance of about £ll with the second oat crop and this about covered the sowing to lucerne or pasture, so that the development of this country was financed out of income.

In the dry period before Christmas Mr McNeilly said that a 30 acre block in grass had carried eight ewes and their lambs to the acre. So far about 750 acres had been broken up and at present about 400 acres were in lucerne or pasture and the balance was in white crop.