Low cost overdrilling technology for pasture establishment

Abstract

<jats:p>A prototype strip seeder was developed to establish grasses and legumes in the semi-arid and montane environments of the Mackenzie Basin and Central Otago. Specifications of the strip-seeder required for cost-effective performance were identified on the basis of previous direct drilling investigations in this environment, and included: (a) removal of a strip of existing vegetation to reduce competition; (b) creation of seed bed tilth; (c) controlled and separate placement of seed and fertiliser; and (d) compaction of the drilled seed bed to enhance contact between seed and soil. The prototype strip seeder was built around a modified Duncan 730 multi-seeder chassis, and was used to install spring and autumn trials at Eamscleugh in Central Otago and at Ohau Downs in the Mackenzie Basin. Mechanical improvements were made as the trials progressed. The experience gained, and results from the trials, confirm the suitability of the prototype strip seeder concept for successfully introducing grasses and legumes into this terrain. Keywords direct drilling, strip seeder, seed placement, seed depth, sowing depth</jats:p>

Comparison of pasture establishment from a conventional disc drill and a prototype strip seeder drill

“…One of the stated aims of the development project was to improve seedling germination by precision depth control of seeding, a factor implicated in poor seedling establishment from conventional disc drills (Campbell et al 1983). Problems were encountered in controlling seed depth in this prototype and in general all species were sown below the optimum depth (Horrell et al 1992). Further development of the prototype drill is At Ohau Downs, birdsfoot trefoil, cocksfoot and upland bromeplant numbers in autumn were significantly higher in the prototype drill than in the triple disc drill.…”

“…Results presented by Horrell et al (1992) indicate clearly that the prototype drill effectively removed a furrow of existing vegetation. The results from Eamscleugh confirm that this mechanical removal of vegetation effectively reduced competition for moisture for the establishing plants.…”

“…The pasture species were drilled with either a conventional triple disc drill or prototype strip seeder drill. Mechanical details are given by Horrell et al (1992). The species used (Table 1) were thoseconsidered to be suited to the different sites.…”

Over-Drilling New Zealand Tussock Rangeland with or without a Previous Legume Phase

“…The establishment treatments were a factorial of two previous developments x two prior herbicide treatments (nil or a light glyphosate spray) x two sowing seasons (spring or late summer) x two drill types (disc drill or experimental drill giving partial tyne cultivation before seeding [7]) x two types of super-phosphate (super or 'maxi-super' of 0:5:0:50, N:P:K:S) at three rates (50 or 150 kg ha -1 yr -1 or 150 kg -1 ha -1 every 3rd year) x two rates of nitrogen in first two years (nil or 150 ka N ha -1 yr -1 as urea) x two spatial replications. Each fenced and grazed plot of 8.5 x 50 m plot contained the subplot combinations of the two drill types and two nitrogen levels.…”

Financial analysis of pasture improvement on Earnscleugh Station

“…From the experiences and results achieved on Shepherd's Flat, four pasture development methods were used according to the various landforms for the simulation. The Jethro drill (Horrell et al 1991) was used on flat to rolling country where rocks did not inhibit access, and the Baker boot drill was used on slightly inclined scabweed faces. On the steeper sunny and shady slopes, seed and fertiliser were simply oversown by plane.…”