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Soil is set to take centre stage at this year's Grassland & Muck event, where experts will tackle issues such as compaction and drainage.

Roughly 70 per cent of UK pasture is suffering from degradation, with 10 per cent severely compacted, leading to poor grass yields and limited access to land following rainfall.

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

According to ADAS experts who will be running the soil and nutrient advice clinic at the event, productive soils need to be both well drained and well structured.

They believe they key is to identify where there may be soil or drainage problems, and then take the correct action to alleviate them.

Signs on compaction or inadequate drainage can include standing water, weeds and poor yields, so farmers should dig a soil pit in these areas, says soil specialist Dr Paul Newell-Price.

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

To learn more about such tell-tale signs, visitors to the Grassland & Muck event will be able to get below ground level in the soil pit to examine the soil profile and identify problem areas.

In addition, visitors can bring a photo of their own soil profile and a soil sample to discuss with ADAS experts, as well as recent soil and manure analysis results.

Around 6.4m ha of agricultural land in England and Wales has been drained with pipe systems in the past, but many have not been maintained and about 60 per cent of soils would benefit from repairing or replacing the drainage, according to Mr Hill.

Many farmers will hold historic draining plans, or may be able to access them through the local drainage contractor, but where they are not available the best option is to look at aerial photos, walk the field and clear drainage ditches to look for outfalls.

Different soils have different drainage needs, which will also depend on the average rainfall in the area.

Kirk Hill, drainage specialist at ADAS, said: "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.

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

“The most common problem with drainage systems is when the outfalls aren’t kept clear – so dig out your ditches and check for running water from the outfalls after rainfall.

“It may be that you only need to replace the final metre or two where the outfalls have silted up or collapsed.

However, changing weather patterns have put the spotlight back on drainage.

"We’re getting more intensive storms, leading to increased risk of soil erosion and loss of soil organic matter.

"Better soil management and drainage will reduce these losses and result in less soil drought, waterlogging and nutrient loss.

"Healthy soils will be more resilient to adverse weather, produce higher yields, and have a longer grazing season. "You’ll also have better uptake of nutrients and more timely field operations.

"Everything starts below ground, if you don’t get your soil right your seeds and other inputs will be wasted.”

Dr Paul Newell-Price, a soil specialist, said: "Half of the soil pit will have been compacted, and visitors can also see a sward lifter, aerator and drum-type loosening equipment in situ, to find out at what depth they work best."