7 May 1999

SPREADING IS ONE ROUTE TO GOOD SILAGE

CUTTING early to cash in on prime grass quality and promote higher second-cut yields by giving a longer period of regrowth has its drawbacks. Chief among them is the higher initial moisture content that means grass takes longer to dry before being ready for clamping or baling.

In a typical UK silage making season, that increases the risk of wetting from summer showers.

Speeding up the drying process can be achieved by vigorous swath conditioning using the modern equivalent of the "wuffler". But more silage makers are adopting the hay-making approach of spreading the grass to increase the amount of crop exposed to wind and sun.

Evaporation of moisture from grass is most rapid during the first hour or so of the crop being cut. After that, the "pores" through which transpiration occurs naturally as it is growing close and the wilting process becomes slower and less pronounced.

Spreading the crop allows maximum surface area of the crop to be exposed to wind and solar radiation, encouraging maximum evaporation during that period. Growers can then choose to use this approach to hit target moisture content quicker or to dry grass more thoroughly during a conventional 24 hour wilting period.

Distribution of grass needs to be as even as possible if the best and most consistent drying performance is to be achieved.

Following the mower with a rotary tedder is an effective means of spreading. But it also introduces an additional operation to the harvesting process. Using the mower to do the job saves the extra cost and time involved.

As ever, manufacturers have been quick to latch on to the concept; several now offer grass spreading kits on their machines, ranging in sophistication from a few vanes bolted to the underside of the grass hood to purpose-designed intensive conditioning and spreading systems.

Vicons HPC remains the only example of the latter. Grass forced between a revolving nylon brush and a metal vein roller is reckoned to be conditioned more thoroughly than when a conventional system is used. The crop is then spread by a free-running rotor across the back of the machine.

Committed?

This arrangement suggests that HPC mower-conditioner operators have to be committed to spreading. But a swathing kit – comprising two swath boards and a reversible plate carrying spreading vanes – can now be fitted. With the spreading roller lifted out of its working position and the vane plate reversed by pulling a lever, the machine lays a tidy swath.

To cater for operators wanting a high capacity mowing system, Vicon builds a 2.4m (7ft 10in) front mounted HPC mower-conditioner for use with its 3m (9ft 10in) rear-mounted or rear trailed models.

Sticking with standard conditioning equipment and relying on angled vanes and the impetus of grass thrown from the rotor is a cheaper means of spreading grass. And with a retro-fit kit, existing mowers can be adapted to the technique.

So Vicons latest tractor mounted conventional mowers – the 2.4m and 3m (7ft 10in and 9ft 10in) DMP models – have this facility as standard.

Novelties include triangular-shaped discs carrying three blades, a conditioning rotor of larger diameter tube than usual, and stumpy conditioning tines – all of which is reckoned to help keep power requirement in check.

Grass spreading vanes are attached to a simple linkage that, after loosening two thumb screws, can be used to adjust their working angle. So the mower can be switched easily between spreading and swathing.

It takes a couple of spanners to alter each vane individually on other machines – if angle adjustment is available at all – although on JFs GX-series mounted mower-conditioners and Kuhn FC-series machines, swath doors are used to gather grass into a swath.

An extended grass hood is part of the design on the 2.4m and 2.8m (7ft 10in and 9ft 2in) JF machines from WestMac, with the aim of smoothing the flow of grass from the conditioning rotor so that the vanes can work effectively to achieve an even spread.

On Kuhn FC-series mounted mowers, a curved blanking plate is fitted to inside the hood to achieve the same effect.

An adjustable, multi-ribbed conditioning plate is part of the Extra Dry system for Pottingers Cat Nova mower-conditioners, enabling the degree of conditioning to be more effectively altered to suit crop type and weather conditions.

Close-spaced V tine fingers convey crop from the disc cutterbar to the rear of the machine, scraping away at the waxy surface of the plant stems as it goes to encourage speedier moisture evaporation.

Individually adjustable vanes on the underside of the rear hood then spread the grass over the mown area.

Five Pottinger mower-conditioners are available in Britain with the Extra Dry system, three tractor-mounted machines with working widths from 2.1m to 2.85m (6ft 10in to 9ft 4in) and two trailed models at 2.56m and 3m (8ft 4in to 9ft 10in).

German manufacturer Nie-meyer fits its Quick Dry spreading vane kit to four different machines, offering a choice of disc or drum mowing, and either fully- or semi-mounted configurations.

The Eurodisc models have been substantially changed to accommodate the new system, with discs now contra-rotating in pairs (rather than all turning towards the centre) to ensure an even flow of grass to a conditioning rotor that now extends the full width of the cutter bar.

Triangular shaped curved blades, bolted to the underside of the hood, do the spreading and this arrangement is available on two Eurodisc tractor-mounted machines, cutting 2.2m and 2.6m (7ft 3in and 8ft 6in), respectively.

A similar design, but using more prominent vanes to cope with the wider working width, is standard fitment on the Niemeyer RO275-HIC tractor-mounted drum mower. This newcomer to the range borrows ideas from the companys front-mounted machines; for example, two larger diameter drums flank two smaller diameter units – an arrangement said to result in easy crop flow and good swath structure when swathing rather than spreading.

Chassis structure

Also, the chassis structure and drive-line are designed to limit the extent of any damage (and consequent repair costs) resulting from accidental impacts while working at speed.

Grass spreading is also an option with Niemeyers novel Semitra mower-conditioners, although the principal design feature is the semi-mounted configuration which shares the weight of the machine between the tractor linkage and an end support wheel in both work and transport.

There are two sizes with drums, cutting 3.05m and 3.65m (10ft and 12ft), and a single disc model also cutting 3.05m (10ft).

In work, the mowing and conditioning assembly is carried on parallel linkage with spring suspension so that ground contours are followed much like a fully trailed mower. For transport, the assembly swings round for towing behind the tractor.

Krone distributor Amazone has two rear-mounted, one front-mounted and four trailed mower-conditioners available with Easyspread spreading vane kits.

Disc-cutting

All are disc cutting machines with tine-type conditioning systems shrouded by hoods made from aluminium to keep the weight down. The same material is used for the aluminium vanes, attached individually by bolts in one of seven positions depending on the spreading width required.

By removing the vanes and closing the standard-fit swath boards, the mowers can lay a conventional swath.

Lelys bolt-on vane kit (which is available for new mowers or for retro-fit to machines already in use) comes with a drilling template to ensure correct angling for an even spread.

It is available on the Optimo 280 and four models from the newer Splendimo range, covering working widths from 2.05m to 3.2m (6ft 8in to 10ft 6in) in tractor-mounted and trailed configurations. &#42

Model Width Cutting Mounted/trailed Price (£)

JF Top Dry

GX2400 2.4m (7ft 10in) discs rear-mounted 7650

GX2800 2.8m (9ft 2in) discs rear-mounted 8695

Krone Easyspread

283F 2.8m (9ft 3in) discs front-mounted 8020

243 2.4m (7ft 10in) discs rear-mounted 8400

283 2.8m (9ft 3in) discs rear-mounted 8600

283T 2.8m (9ft 3in) discs trailed 13,250

323T 3.2m (10ft 6in) discs trailed 13,700

4000T 4m (13ft) discs trailed 22,500

4000T 4.8m (15ft 9in) discs trailed 26,500

Kuhn

FC240P 2.4m (7ft 10in) discs rear-mounted 7395

FC280P 2.8m (9ft 2in) discs rear-mounted 8330

FC302GD 3m (9ft 10in) discs trailed *13,610

* Blanking plate to direct grass to ground before reaching swath doors also available as retro-fit for FC300GD mower-conditioner.

Lely

Optimo 280 2.8m (9ft 2in) discs rear-mounted 6870

Splendimo 205 2.05m (6ft 8in) discs rear-mounted 7180

Splendimo 240 2.4m (7ft 10in) discs rear-mounted 7425

Splendimo 280 2.8m (9ft 2in) discs rear-mounted 8095

Splendimo 320 3.2m (10ft 6in) discs trailed 11,815

Niemeyer Quick Dry

Eurodisc 220-C 2.2m (7ft 3in) discs rear-mounted 6250

Eurodisc 260-C 2.6m (8ft 6in) discs rear-mounted 6950

RO275-HIC 2.75m (9ft) drums rear-mounted 9350

Semitra SM310-IC 3.05m (10ft) discs rear semi-mounted 12,750

Semitra RO305-HIC 3.05m (10ft) drums rear semi-mounted 13,500

Semitra RO375-HIC 3.65m (12ft) drums rear semi-mounted 14,750

Pottinger Extra Dry

215 Cat Nova ED 2.1m (6ft 10in) discs rear-mounted 6990

250 Cat Nova ED 2.45m (8ft) discs rear-mounted 7590

290 Cat Nova ED 2.85m (9ft 4in) discs rear-mounted 8390

260 Cat Nova TED 2.56m (8ft 4in) discs trailed 11,990

310 Cat Nova TED 3m (9ft 10in) discs trailed 13,790

Vicon

DMP 2401TC 2.4m (7ft 10in) discs rear-mounted 7550

DMP 3001TC 3m (9ft 10in) discs rear-mounted 8250

Vicon High Performance Conditioner

AM2400HPC 2.4m (7ft 10in) discs rear-mounted *11,430

FM3000HPC 3m (9ft 10in) discs front-mounted *15,650

KM3000HPC 3m (9ft 10in) discs trailed *19,450

* With swath door kit – £12,180; £15,950; £19,750.