Plan cultivations carefully this autumn
Growers need to think very carefully about what cultivations are needed this autumn, and only do what is necessary to achieve the best crop establishment in any particular situation ...
Soil properties, moisture availability, cropping, grassweeds, and the ability of drill equipment to handle crop residues, should all be taken into account before deciding on the best approach, Hutchinsons technical manager, Dick Neale, says.
“And, avoid over-cultivating. Fluffy, fine seedbeds may look good at first, but they lack structural integrity, so will be more prone to slumping, and capping after the first heavy rain.
“Previous seasons have shown how this can lead to waterlogging, surface runoff and reduced crop establishment, or even crop failure. It will also be far harder to travel on ground that has been overworked, potentially compromising spray or fertiliser application timings throughout the season,” he says.
On soils with a high clay content, there will have been a good deal of natural fissuring during the dry spring and start to summer, which may negate the need for deep subsoiling in some situations, Mr Neale continues.
“There is no substitute for getting into the field with a spade to check soil health and structure. If compaction is suspected, check where, and how deep, it is, before rushing in with the subsoiler. Subsoiling unnecessarily, to the wrong depth, or in the wrong conditions, can just make problems worse.”
Mole draining
If drainage issues have been identified, mole draining can have a major benefit, as has been seen at the Hutchinsons black-grass demonstration site near Cambourne in Cambridgeshire.
But it must be done well to avoid making problems worse. Soil conditions need to be dry enough on top to take the machines, but still wet enough at depth to hold the mole shape. Growers also need to check how deep to go if planning to mole into the gravel backfill above field drains, Mr Neale advises.
“If mole draining is needed, in some situations, the rotation may need to be adjusted to create opportunities for mole ploughing problem areas in the autumn, or be willing to grab the opportunity to do it through the crop in the spring.”
Grassweed strategy
The presence of grassweeds can also influence cultivation strategies after harvest.
Stale seedbeds, for example, have been a very successful tool to help manage black-grass over the past decade, and still have a place in some situations, but Mr Neale says changes to emergence patterns seen at Cambourne and elsewhere, may limit their effectiveness for black-grass, or even be a negative for meadow brome.
“Black-grass germination is becoming far more protracted, continuing well into winter, and spring, so the traditional late-September/early Oct peak in emergence is now much smaller. This is more akin to ryegrass, which has always shown a variable germination pattern. Sequencing herbicides plays a key role in tackling this situation.”
He also says rotational ploughing will be less important for managing black-grass this season, given generally good levels of control and lower seed return this harvest, however it can still be beneficial where meadow brome is an issue.
“Growers have to weigh the benefits against the costs in terms of time, fuel, wearing metal, etc, and what seed you might bring back to the surface.”
Generally, meadow, soft and rye brome should be left on the soil surface for one month to ripen, before a shallow cultivation to place seeds in moisture, and then spray-off emerged weeds. In contrast, barren and great brome seeds can be cultivated and buried as soon as possible after harvest.
Making soils work for you
Understanding the physical, chemical and biological nature of your farm’s soils is another key part of cultivation planning, and for deciding on the best approach in specific fields, Hutchinsons soils specialist, Jade Prince, adds.
“Start with what you know. Were there any soil-related issues, such as waterlogging or compaction earlier this season, or previously? Which areas were affected? Are there obvious causes?”
Visual inspections are a great starting point, but for more detailed soil analysis, Terramap offers a valuable way of mapping large areas to identify any number of potential issues quickly and accurately, whether structural, nutritional, or other.
“At our Cambourne grassweed demonstration site, for example, poor drainage has been a major issue on the heavy land, but Terramap analysis revealed soils also have a very high magnesium:calcium ratio, making them ‘tight’ and harder to work.
“This has been addressed with the addition of gypsum in recent autumns – gypsum allows magnesium to be flushed lower into the soil, so the seedbed becomes more friable.”
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