It was standing room only at SAC Consulting’s recent soil aeration event at SRUC’s Oatridge Campus.
Hundreds of farmers, young, and not quite so young, packed the seminars and displays at the Equestrian Centre, seeking solutions to the growing problem of waterlogged soil.
There has been a phenomenal amount of rain recently, particularly at the end of last year, which has seen a rise in problems such as surface capping (the breakdown of the soil surface structure), erosion, compaction and poaching. Soil structure and fertility can be severely affected when the soil is soaked, and many of the nutrients will be lost.
SRUC Soil Scientist Dr Bruce Ball gave the 300 plus crowd guidance on how to restore soils suffering from compaction. He recommended using aerators for remediation of topsoil, while for subsoil compaction farmers need to create fissures, or cracks, that will increase drainage and allow root movement without breaking down the structure of the soil.
“Although it is difficult, farmers should try to reduce subsoil compaction by reducing the weight of their machinery. I like to limit the axle load to no more than eight tonnes, while wide tyres will help reduce ground pressure.” Bruce said.
Senior Agricultural Consultant Seamus Donnelly spoke passionately in urging farmers to check and maintain their drainage systems. As a drainage specialist with over thirty years experience Seamus has seen much knowledge on drainage lost and he believes it is now time to ‘save our soil’ which he called ‘our greatest national wealth’.
The current fertility of some Scottish soils can be an indicator of just how much quality has been lost. Seamus flagged up recent research which found that studied 1000 soil samples collected in south west Scotland and found that over half had a pH below 5.7. A pH closer to neutral would be optimum for that area, somewhere around 6.2 to 6.5.
“It could be that old systems are now failing,” Seamus said, “drainage schemes don’t last forever, they will silt up. I hope that future SRDP grants will focus on reseeding and drainage. It is a worthwhile use of public money as they help reduce farming’s carbon footprint, they relieve flooding, and of course will be vital as the need to produce more food intensifies.”
Well drained fields improve crop and grass yields, allow for strong root growth, are better for animal welfare (many diseases thrive in very wet conditions), and mean less soil damage and surface run off.
Seamus gave the audience a stark example of the detrimental effect of poorly draining soils. On well drained soils 40 tonnes of potatoes can be grown per hectare while poorly drained fields might see yields of just 15 tonnes per hectare.
While many concerns were tackled during Bruce’s and Seamus’s seminar, for those interested in a more practical session Grasslands Researcher Dr Paul Hargreaves was to be found standing waist high in a ditch in a snow encrusted field. The ditch had been cut out of the field to show how sward lifting had improved drainage.
Paul said sward lifting at about 20cm can help to get air and structure into the soil. “Farmers should be looking to sward lift when it is dry but not too dry.” He said. “August is usually a good time but it just depends on the weather. In our next round of crop experiments at SRUC we will be measuring the moisture levels when sward lifting so we will hopefully be able to give the ideal moisture level in the future.”
Farmers are now looking not to rain-soaked past but to what will hopefully be a bright and averagely rainy year. However, they now have the tools to make the most of their soil, whatever the future brings.
This event was part-funded by Scottish Government as part of its public good, veterinary and advisory services. Other partners included QMS and Scottish Farmer magazine.