Dick Neale, technical manager of Hutchinsons, who has surveyed soils on the Claydon farm and found them to be in optimum condition, with excellent structure and permeability used coloured dye to highlight how worm burrows allow water to permeate the profile and root structures to develop.
He stated: “The Opti-Till System generates enormous benefits to soil biota, soil structure and crop performance, with only straw returned to the soil and no organic matter added from other sources such as manures or digestate.
“Conventional full cultivations and min- till systems can over-work the soil, while sunlight kills the bacteria in the inverted soil. These methods also reduce worm populations by up to 80%, inhibiting the soil’s ability to drain water away in wet weather and increasing moisture losses in dry conditions.
“Starving the crop’s roots of essential air and nutrients reduces yield potential and increases the cost-per-tonne of production, while the risks from flooding and soil erosion are substantially higher.
Similarly, the use of min-till systems and disc-type direct drills results in soils which drain poorly and flood easily, creating crops with poor rooting structures and low yield potential.”
This spring Mr Neale’s work on the Claydon farm included taking 10 spade-sized soil samples from a field of winter wheat and in one he found up to 52 epigeic, anecic and Eedogeic worms.
“That tells me that the soil is in good shape,” Dick Neale stated. “Worms burrow up to 2m deep and are fundamental to efficiently draining and oxygenating the soil, acting as pumps by pushing oxygen around the network of burrows as they move through the profile. If soil has 30 deep-working earthworms per square metre things really start to happen and the benefits quickly become apparent.”