A comprehensive assessment of soil health including physical, chemical and biological properties, with interpretation of results by a soil specialist and follow-up recommendations on how to improve soil health, is the aim of a new service launched by Hutchinsons.
‘Healthy Soils’ is aimed at growers looking to tackle underperforming areas of the farm, explains Andy Hoyles, commercial development manager, nutrition, at Hutchinsons. “It is a practical-based service looking at individual parts of the farm which may be underperforming on yield or have soil type variation. We are trying to get to the nitty gritty of why a soil performs as it does.”
As well as testing for traditional parameters such as P, K, Mg and pH, the latter being measured at three different depths, the £250 customer soil audit includes testing for other key nutrients, a soil texture assessment (clay, sand and silt percentage), visual evaluation of soil structure, assessment of water infiltration, a cropping and cultivations review and a look at key organisms and earthworms.
Distinguishing between total and available nutrients, nutritional information is presented in Kg/ha, a more relevant measurement to farmers than mg/l, says Dick Neale, Hutchinsons technical manager. “We can discuss with farmers how nutrients in their soil interact.”
Soil assessment is best done from March into April, says Mr Neale. “Timing is key. You need the soil at adequate moisture and when earthworms are more active. Harvest is the wrong time as soil is too dry.”
Soil structure is scored using a VESS test, a well-recognised benchmark of soil structure, says Mr Neale. “We look at worm holes, colour, compaction, smell – an indicator of biological activity, size and appearance of aggregates and root penetration.”
Compaction remains a barrier to optimal soil health, says Mr Neale, with heavy machinery such as sugar beet harvesters causing compaction lower down in the soil profile even though flotation tyres may be protecting the surface. “It can only be dealt with using cover crops, anesic worms, which go deep, or a good rotation.”
Adrian Abblitt, who farms and does contracting on 972ha (2,400 acres) at and around Grange Farm near Huntingdon, Cambridgeshire, grows winter wheat, oilseed rape and spring barley on clay soils.
He has used shallow tillage to a depth of 50mm for the last six years, no longer rotational ploughing, to help with black-grass control. All crop residues are returned to the soil. This year he will chop residues finer to 50mm for better spreading and faster processing by worms.
Mr Neal scored a soil sample from Grange Farm at 2 on a scale of 1-5, 1 being the highest, using the VESS test. This is a high score for an arable soil.