Comment

DAIRY farmers could be losing more than £25 per cow through poor soil management, according to experts who attended an MDC farm meeting in Devon, held in conjunction with the Farming and Wildlife Advisory Group.

Many producers don't realise their grassland is compacted, resulting in poor nutrient and water uptake, lower yields and higher machinery wear, says Chris Coxon, south-west extension officer at the Milk Development Council. It also increases the risk of water runoff and erosion, which can result in water pollution and flooding.

"Dairy farmers need to be aware of soil problems on their farms, as they not only affect profitability, but could also contravene environmental legislation," he says. With environmental schemes and legislation becoming ever more prevalent the MDC has organised a series of on-farm events to highlight potential problem areas and offer practical solutions.

The first of these events concentrated on soil management, hosted by dairy producers David Munday and Jean Howard at Town Barton Farm, Crediton, Devon. The day included sessions on cropping, compaction and erosion in grassland and arable fields.

"The first thing to do is to ascertain whether there is a compaction problem in your fields," says Mr Coxon. "Get out and dig a few holes, starting near a gateway or water trough to find out what to look for, as these areas will be compacted." Common signs of compaction include poor or shallow root structures, horizontal layers or cracks in the soil and a lack of earthworms.

Annabel Keast, farm conservation advisor at FWAG, says grass grown on compacted soil takes up just half the nitrogen of that grown on a good soil structure. "For every kg of nitrogen applied to a good grass sward there is a yield response of 20-30kg of dry matter, but in compacted swards that response is reduced to just 10-15kg."

So on good pasture 200kg of nitrogen will yield 12t of dry matter (DM), costing 3.6p/kg of DM. But on a compacted field, the same nitrogen application will produce just 6t of dry matter, increasing its cost to 4.8p/kg.

Fields used for grazing, rather than silage production, are similarly affected, she adds. "A dairy cow eating 13kg of dry matter a day for 180 days will cost £84 in nitrogen on good soils compared with £112 on compacted soil - a saving of £26 per cow."

Compacted grassland is also more likely to be affected by summer drought, leather jacket infestations, urine scorch and runoff in wet weather. Solutions include using a sward lifter, subsoiler or plough, depending on the depth of compaction.

"To avoid compaction try to work soils in the driest condition possible and remember that 50 per cent of compaction happens during the first pass of wheelings," says Mr Coxon. A second pass causes just an extra 10% of compaction, so it is important to use temporary tracks even when silaging, and consider removing them afterwards or during the next cultivation.

Soil structure has an important impact on runoff and erosion, he adds. But farmers must also consider the inherent risk in the shape of the field, slope, rainfall and soil type. "In addition to this you should be aware of the manageable risks like cropping, cultivation techniques and machinery choice."

Careful management of high-risk fields - for example those on slopes with a road, stream or property at the bottom - is essential to avoid flooding and erosion, says Mr Coxon. "Choose the correct crops and varieties to reduce the need to be on the field during wet conditions. Also look at the crop higher up the slope - rainwater washing off a compacted field above will only exacerbate the problem."

Buffer strips are a useful option under the Entry Level Stewardship scheme, not only do they reduce runoff, they will increase the diversity of habitat on your farm. And careful fieldwork planning will also reduce the risk of erosion. "Is ploughing necessary for the next crop? Also, if you are reseeding a high-risk field, pasture renovation through over seeding may well be a good option."

The MDC's next meeting will be held in March and will consider the implications of extended nitrate vulnerable zone areas. Topics will include slurry storage, the potential to reduce required storage, and spreading options to ensure that slurry and farmyard manure is properly utilised.

For more information and to book your place call Chris Coxon on 07989 959517.

11:49am Tuesday 12th February 2008

Print

Email this

Comment

Add your comment

Name:
Email: *
Location:
**
	e.g. 123-123
Comment: Please note: All HTML tags will be ignored. Format Text:
By posting a comment, I confirm that I have read and agree to the terms of use. Comments are not moderated but we will react if anything that breaks the rules comes to our attention and we may delete inappropriate postings. Please treat other people with respect. You must not post anything that is abusive, indecent, unlawful or defamatory. Remember, you are personally liable for what you post on this site. If you wish to complain about a comment, contact us here.
* Your email address will not be displayed ** To avoid register now or login