Oversowing Experience

Press, Volume CV, Issue 30983, 12 February 1966, Page 8

Oversowing Experience

There are few men better able to talk about the aerial oversowing' of high country than Mr Bill Chisholm, manager of Molesworth station, with the experience of some 40,000 acres of oversowing behind him.

i Discussing the oversowing ■ technique recently he emphasj sised that while results were i not at first spectacular there I was a snowball effect over the i years and the end result re- : presented a transformation. In the first year, he said, results of oversowing were i usually most discouraging. ;and it was not until the third ■ year that they showed up I very appreciably, but from I that time onwards there was I a snowballing effect and at 10 years Or thereafter excellent pasture and cover was established on what was otherwise barren country. The appearance of sorrel was a worth-while indicator of the time to sow, he said. On Molesworth pilots were j instructed not to sow above the line of sorrel- The sorrel line would extend, he added. Sowing should be at a rate of not less than 101 b to the aere—cocksfoot, white clover, alsike and Montgomery red ! clover. On Molesworth they had sown successfully from I September to December, but so as to get the last J of the frost heave. In most cases clover estabi lished without fertilisers. The (use of fertiliser on Moles- ! worth had the effect of stimu- ; lating the growth of clover I which would not appear in any great profusion until November and disappeared in late March and April with the first frosts. Taking into account the length of the grazing period and the outlay this meant that the use of . fertiliser was too costly.

I Cocksfoot, on Molesworth appeared to be able to fix sufficient nitrogen without clovers, and in many instances clover establishment came after the successful establishment of cocksfoot, especially on bare shingle and scree faces. Nevertheless there were large areas where clover and cocksfoot progressed together. Oversowing of tussock cover with cocksfoot would, however, be disj appointing. If seemed that [ the lack of success of cocksfoot in these circumstances could l>e caused by lack of i moisture.

Because each locality would differ, Mr Chisholm said that no restriction on the height at which oversowing could be done could be stated, and only those actually doing the oversowing would know the limits in their own area. On Molesworth they could exceed 4000 to 4500 ft in places.

“A transformation has taken place on a good deal of oversown country on Molesworth with almost complete

coverage of introduced grass and a surprising and rapid increase iti tussock and native species of grass.” At this stage, he said, considerations of conservation had been met and at the same time the country was able to provide sustained grazing.

On Molesworth they tried to control grazing or give light grazing during the seed setting period. They had achieved a remarkable increase in natural reseeding with as little as six weeks of spelling in December and January.

A -salient factor in the successful establishment of ! oversowing on the station had I been grazing with cattle only. ' This had resulted in compac- : tion of the seed cast on the [ground and the carrying of ' white, alsike and Montgom- , ery red clover in the autumn. ; Grazing with sheep would ' necessarily have to be con- [ trolled more closely than [with cattle, but many sheep j men had still successfully 1 oversown their country.