Mower conditioner
Introduction
In the past, conditioners required two operations, with separate implements, to pick up and condition the crop.
With higher capacity tractors and a need for greater efficiency, mowers (usually disc type) that incorporate conditioners have been developed.
There are now mower conditioners with a cutting width of about 5.5 m that are capable of cutting 1.0-1.5 ha/hr/m width of cut.
They require up to twice as much power as mower-only machines, to maintain output and performance, typically 15-25 kW at the PTO per metre width of crop cut.
There are essentially two main types of conditioners – roller and flail.
Roller conditioners operate by either ‘crushing’ or ‘crimping’ the cut forage with rubber and/or steel rollers of various designs.
The crimping types leave a number of breaks at intervals along the stem, whereas the crushing types split the stem along its length.
The flail-type conditioners use a variety of metal, polyethylene or nylon spokes or tynes, which may be either straight or vee shaped, a series of rotating nylon brushes, or various combinations of these.
Conditioners vary in their suitability for various crops and pastures.
Roller conditioner
Research has shown that roller conditioners are the most suitable for ‘stemmy’ crops, such as sorghum, cereals and stemmy leguminous crops with a tall growth habit such as balansa, Persian, berseem and arrowleaf clovers and lucerne, but can be used for all crops and pastures.
As a general rule, the tyned conditioners should only be used for grass-type pastures and crops such as ryegrass, early cut millet and cereals, and non-stemmy legumes, such as sub and white clovers and medics.
Conditioners fitted with nylon brushes have a role in ‘softer’ pasture-type forage.
The way the machine is set up and the skill of the operator will have a bearing on the effectiveness of the operation.
Machines adjusted incorrectly may either over- or under-condition the forage.
Conditioners increase the rate of wilting in two ways. They damage the outer waxy protective layer (cuticle), allowing moisture to pass through the plant surface more freely.
They also damage the stem, increasing the rate of moisture loss from these areas. Forage should not be over-conditioned; this will cause increased loss of Dry Matter (DM). The leaf fraction, which is the highest quality component of the forage, is particularly susceptible to over-conditioning.
If a separate conditioner is used, this operation should follow as soon as possible after cutting to be most effective and to minimise DM losses. Many mower-conditioners and conditioners now have adjustable swath boards or deflector plates to allow mown forage to be left in very wide swaths.
Flail conditioner
The ideal drying swath will have the stems of the crop on top of the swath, be widely spread and left ‘fluffy’ to allow airflow through the swath and for the moisture to escape.
The demand for greater capacity has resulted in longer cutter bars on mowerconditioners.
Combinations of front- and rear-mounted mower-conditioners or tandem-mounted mower-conditioners have also increased cutting widths. These can have overall mowing widths above 7 m, and cutting rates up to 10 ha/hr.
The latest development has been the self-driven mower-conditioners, incorporating two side mower-conditioners and a front mounted mower-conditioner with cutting widths of about 9 m and cutting rates of up to 10 ha/hr.
Intensive mechanical conditioning
Recent research in the United States, Canada and Australia has compared drying rates of forage using various machines – those that heavily condition crops at mowing, and high-performance or intensive mechanical conditioners (maceration, mat making or super conditioning).
These high-performance conditioners are in the early stages of development. Table 6.2 shows the relative drying rates that can be expected from a range of machines designed to increase forage drying rates.
The maceration system combines four steps into one machine: mowing, macerating it through a series of serrated rollers, compressing the mashed forage into thin mat, and depositing it on the stubble for field drying.
Macerated forage can dry 2-3 times faster than conventional windrows. Although use of maceration systems has been shown to improve quality of lucerne hay produced, with significantly less field losses, its role in silage production is still being evaluated.
