OPTIMISING OILSEED EARNINGS
Phillip Wright
Preparing an ideal seedbed for oilseed rape revolves around getting three elements right - ensuring a good surface tilth; getting the right structure and drainage in the subsurface and achieving effective consolidation to the full seedbed depth, says Simba’s technical consultant Philip Wright.
He was speaking to farmers attending two busy seminars hosted by the company during the Doe Show.
Simba has gained a huge volume of experience of the subject while developing its cultivators, which it has recently published in its book “Harvesting the growing opportunities presented by Oilseed Rape”, that is available from the company *
That knowledge has been essential in the development of machines like the X-Press, Solo and – most recently – the new SL range: “If we didn’t understand what the plant itself required, we could not really design the right machinery to help you establish it efficiently”.
The first element to address is the surface, Philip says: “It needs to have a fine, consistent tilth, which gives you the best possible chance of placing the seed to the desired depth – anything between 10mm and 20mm (under one inch) to ensure you get optimum emergence.
“Crumb size is also important, with germination dropping off sharply as tilth gets coarser than 19mm average. We recommend you aim for a mix of aggregates between 6mm and 15mm”.
The extent of sub-surface work required depends on a range of factors, notably any damage or compaction carried over from the previous crop, and the soil type and condition:
“On any soil type the crop’s root growth will be restricted by compaction. Work completed by many researchers over the years has shown the close correlation between root development and eventual yield.
“So it is essential to remove any compaction and ensure a well structured sub-soil – one that facilitates movement of moisture in both directions and enables the plant’s roots to access both moisture and nutrients. In crops where compaction has not been removed efficiently you can see roots working laterally, which restricts their efficiency”.
At the same time, the crop benefits from effective consolidation, both on the surface and to depth:
“This closes air pores so that moisture can move up and down through the soil profile. If air pores are too large, then water will struggle to move either way, so water will not drain away after rain, and the crop will struggle to draw water up in dry conditions”.
When performing operations to remove compaction it is important to move all the soil, he says, so that no compacted zones remained that could inhibit root system development:
“Our advice would still be to sow any crop in line with the cultivating tine, and preferably after a roller, so it can access the zone with the best structure, but to ensure that compaction is broken up right across the seedbed to assist root system development.
“But in doing this, it is vital that the tine has the correct characteristics to avoid bringing up clods from depth, whilst being effective at removing any compaction”.
* For your copy of “Harvesting the growing opportunities presented by Oilseed Rape” contact Mark Dolby, Simba International Ltd, Woodbridge Road Industrial Estate, Sleaford, Lincolnshire NG34 7EW (tel 01529 304654; or mark.dolby@simba.co.uk) or log onto www.simba.co.uk and complete the application form.
