The machinery needed to crop raised beds requires only one additional, specialised implement—a bedformer, which also converts to a bed-renovator. The remaining machinery is exactly the same as that needed to crop normal seedbeds, except for some minor adaptations to allow it to track in furrows and operate on raised beds. Machinery adapted for bed farming retains all the capabilities needed to crop normal seedbeds. Every implement is interchangeable.
Forming beds
The single most influential change in management to achieve this objective is a commitment to adapting the track width and tyre size of machinery, as this will prevent traffic compaction from being imposed on the soil in the beds. A 100% controlled-traffic regime is a prerequisite to maximising the performance of, and return from, raised beds.
The choice of trackwidths of 1.83m and multiples of this width and 0.45m tyre width require no factory approval to retain the manufacturer’s warranty and are the best against all of the criteria.
The objective of raised-bed farming is to create and maintain soil conditions that will allow soils to drain and aerate and so prevent waterlogging. The operation of farm machinery must be consistent with this objective if the investment of time, effort and dollars put into raised beds is to gain maximum return.
There is no single best track width and tyre size (bed spacing and furrow widths) provided soil conditions in the beds are created to ensure they will drain and aerate. The choice can and should be made on the basis of practicalities and cost.
The choice of a standard track width and tyre size for machinery used for raised-bed farming depends on:
- The difficulty and cost of adaptations.
- The versatility of adapted machinery.
- The return on the investment of time and effort.
- The re-sale value of adapted machinery.
Bed-formers can be supplied as three-point linkage or trailing models. New machines will cost between $30 000 and $40 000, depending on the variety of detachable components purchased to add to its versatility.
[1]
Figure 1. Raised bed former with marker arms.
Some growers have made their own bed-formers by converting old rippers or deep cultivators. These often have hydraulic stump-jump rams on their ripper shanks. Mostly they are trailing machines and the cost of a second-hand ripper and its conversion to a bed former is about $12 000 to $15 000.
The old rippers that have been converted to bed-formers lack the versatility of the specially made machines. In particular, their framework limits options for rearranging components to allow the machine to renovate existing beds.
[2]
Figure 2. Raised beds renovation bar with marker arms crossing the tail drain at the bottom of the paddock