New tools are to be made available to growers to help assess soil organic matter after research found that changing management practices to increase levels could raise net profits on average by £80/ha.

Developed by GY Associates, in partnership with Rothamsted Research, the KeySoil computer models will enable farmers not only to benchmark their soil organic matter, but also to gauge the likely impact of management practices and to track those changes over time.

The simplest model, KeySoil Range, allows growers to input organic matter levels obtained from soil tests and benchmark their situation against a national soil database, says Nicola Hall, a research consultant for GYA.

The amount of organic matter will depend on how the soil has been managed and soil type. "For example, 2% might be very poor for a heavy clay soil, but very good for a light sandy soil," she says. Comparing the current position for the soil will give some indication of the potential for change.

The next step is to input some simple historical information, such as previous crops, yields, whether any organic matter inputs - for example, slurry, poultry litter or sewage sludge - have been applied in the past five years, into the KeySoil Status program. Those indicators are used to assess whether the management used is likely to maintain, reduce or increase soil organic matter, says Dr Hall.

"A third part of what KeySoil can do is look at future management, and look at the impact of changing practices," she adds.

The tools were assessed in a DEFRA/Natural England Catchment Sensitive Farming Delivery Initiative project on farm. "It made some of the growers using the tools think carefully about their management," says Dr Hall.

That project studied first-hand the experiences of more than 100 farmers and showed that improving soil organic matter could net typical benefits of £80/ha a year. In some cases it was well over £100/ha, adds Dr Hall. "A typical example was where a farmer had switched to incorporating straw over a period of five years and found the number of cultivation passes required had reduced from two to one. On farm we could cost that out using actual figures."

Benefits could be realised within two to five years, she says. "Benefits will vary from farm to farm depending on the farm systems. But, overall, 85% of farms studied showed financial gains from improving soil organic matter management."

The KeySoil team will be on the Rothamsted Research stand at Cereals 2008 (11-12 June) for growers wanting to find out more.

Keysoil tools

• Benchmark soil organic matter levels against national database
• Input field history to assess impact on OM
• Assess management plans
• Could result in £80/ha benefit