COMPACTION is a serious problem in many grassland soils, but attempting to cure it could be hazardous if the underlying drainage is failing, visitors to Grassland and Muck will hear.

The event will spotlight soil health following a survey which showed that around 70% of UK pasture is suffering from degradation – with 10% severely compacted, leading to poor grass yields and limiting access to land following rainfall.

Farmers who are considering alleviating such compaction should check the field drains are working first, or they could be wasting their time, according to ADAS experts.

They will be running the soil and nutrient advice clinic at this year’s event.

“I go to many sites where people have enough or even more drainage than they really need, but the soil is too compacted for water to pass through to reach the drains,” piunted out Kirk Hill, drainage specialist at ADAS, who will lead advice on the subject.

“On the other hand, there is no point subsoiling if the drainage isn’t working – you could cause more damage than you relieve.”

He said the key was to identify where problems lie and take the correct action to alleviate them. Signs of compaction or inadequate drainage can include standing water, weeds and poor yields, so farmers should dig a soil pit in these areas, added soil specialist, Dr Paul Newell-Price.

The pit should be at least 60cm deep and farmers should look at the soil structure and colour as well as root depth, plus note the presence of worms.

To learn more about such tell-tale signs, visitors to the event will be able to get below ground level in a specially dug soil pit.

“Half of the soil pit will have been compacted and visitors can also see a sward lifter, aerator and drumtype loosening equipment in situ, to find out at what depth they work best,” added Dr Newell-Price.

ADAS Soil advice clinic

Times: 10:00 – 16:00 both days

Located on the ADAS stand, this free clinic will be hosted by Mel Holloway and Milly Bowden, two experienced advisors who will discuss soil and nutrient challenges.

They can help in three ways – help with drainage or structure problems (bring a photograph and if possible dig a soil pit and take a clear image of the soil profile); soil texturing (bring along a sample; nutrient and manure application and planning (bring any recent soil and/or manure analysis results.

Soils and nutrient talks 10.30, 12:30 and 14:30

- Practical guide to assessing and improving soil structure for profitability Good soil structure is key to profitability. Learn how to assess soils and choose the right management options from compaction alleviation to reseeding; maximise profit from grass. Speaker: Dr Paul Newell Price, ADAS

11.00, 13.00 and15:00

Managing drainage to improve productivity Drainage is key to maintaining healthy grassland soils. Hear how to take simple steps to improve soil drainage and boost the productivity of your grass. Speaker: Kirk Hill, ADAS

Guidelines for better ensiling

GETTING SILAGE quality right means care and attention to both the clamp and the ensiling process – with this being one of the hot topics at the event.

When biological processes at the clamp go wrong, this can result in average losses of 20-25% – something visitors to the event can learn to avoid from new ensiling talks this year.

According to Will Wilson, business development manager at Bock UK, clamp design is key to both the quality of silage and ease of ensiling. Too often they are too wide, too long and overfilled, he told The SF.

He recommended installing sloping walls, as they improve compaction against the panel. but farmers should avoid making the clamp too wide.

“The face is the second highest cause of waste in the clamp, so should be as small as possible,” he said.

“Face size should be determined by the speed of emptying, and the face should move back at least 2m a week.

“It is also advisable to consider the clamp situation – make sure it is easily accessible to feed cattle and has no back wall so it can be expanded – always keep the future in mind,” he added.

Ideally, clamps should point away from the prevailing wind and sited above ground for ease of construction – though below ground clamps do trap carbon dioxide, thus reducing aerobic spoilage.

The ensiling process is just as vital as clamp design, with density important, requiring thin layers of no more than 15cm, added Dr Dave Davies, of Volac.

“The target is 700kg of fresh matter per m³; which, depending on the silage dry matter, is approximately equivalent to 220kg of dry matter per m³,” he said.

Chop length should be adjusted according to dry matter, as a longer chop with high dry matter will not produce the right density and will be too bouncy.

If grass is above 30% DM, chop to 1.5- 2.5cm; if it is 20-30% DM, chop to 2.5-5cm and if less than 20%, increase chop to 10cm to prevent clamp slippage.

Aerobic spoilage can cause losses of up to 25% in the clamp, and most problems at feeding are because the clamp was filled incorrectly and at the wrong density, he said.

“The use of additives can protect against aerobic losses, but the choice can be confusing,” he warned.

“When selecting one, look at advice from AHDB and ask if there have been independent trials to prove the benefits to livestock.”

Will Wilson and Dave Davies will be giving ensiling talks alongside clamp demonstrations at this year’s event.

New fertiliser advice

VISITORS to the event will be the first to get access to some essential reading which will help them with the fertiliser plans.

The AHDB Nutrient Management Guide (RB209) will be being launched at the event on the AHDB stand (323).

What makes this one special is that it is the first to be produced following a £98,000 project to review the current manual.

It was overseen by the AHDB-led UK Partnership for Crop Nutrient Management and delivered by an ADAS-led consortium of experts from across the UK research community.

It was supported by £200,000-worth of in-kind funding by industry. So this review takes account of the latest research developments since 2009.

It is split into six distinct themed work packages – principles of crop nutrient management; organic materials; grass and forage; cereals and oilseeds; potatoes and horticulture.

Farmers, growers, agronomists, breeders, researchers, fertiliser companies and other industry experts were among those consulted on how recommendations could be improved to incorporate the latest scientific advances.

Paul Westaway, who chairs the livestock technical working group, said: “We are particularly proud of the changes to the nitrogen recommendations for grass, as we have made them simpler to use and focused on what yield farmers need to produce to maximise home grown grass and forage in diets.

“For farmers and growers producing and using organic materials, the updated figures in the organic materials section will be very useful when calculating their nutrient and financial values.”

The new format offers best practice guidance and is the first new edition since it was published by Defra in 2010.

Key changes for grass and forage crops:

Nutrient recommendations for grass and forage crops have the inclusion of guidance on how to use the field assessment method to calculate soil nitrogen supply.

Grassland nitrogen recommendations have been revised to focus on target yield of grass production without linking to particular animal production systems (dairy, beef or sheep), milk yield, stocking rate or concentrate use.

The number of tables have been significantly reduced and simpler to use.

Whole season nitrogen requirements and nitrogen application sequences are provided separately for cutting and grazing situations.

No changes have been made to phosphate and potash recommendations for grazing, silage or hay systems. „ The recommendations for nitrogen use in autumn grass establishment has been increased.

Minimum changes have been made to nutrient recommendations for maize and wholecrop silages

The nutrient advice for swedes, turnips, rape and kale have been altered to reflect more grazing in-situ, so fewer nutrients are being removed off the field.

The nutrient recommendations for fodder beet have been increased as higher yields are being targeted.