The regular assessment of earthworm populations will provide farmers with important perspectives on the overall health status of their soils,” according to Kingshay consultant Jo Scammell.
“Numbers can be pretty meaningless in this context,” she said.
“The key indicators are the size of the worms and their colour. Those that are large, active and having a deep red hue are actively feeding. These, in turn, will be working to improve soil structure and its drainage capacity.
“In contrast, earthworms that are inactive and very pale in colour are not feeding. As a consequence, these will not be acting to improve soil structure.
“This scenario is commonly found in the wake of flooding, drought or the inappropriate spreading of slurry.”
Scamell was a speaker at the 2016 Ulster Grassland Society Conference. She said that a small ‘the spade’ should be one of the most important tools on every farm.
Monitoring what is happening below the surface is crucially important in determining what is happening within a soil.
Smell also important
Gauging earthworm numbers is essential. But the smell of a soil sample is also a key barometer of its overall health status.
“If a strong compost odour is evident, then the soil’s ability to grow high yielding crops is evident. But a rancid or putrefying smell is an immediate indicator of poor soil structure.”
Scammel pointed out that calcium and sodium are soil nutrients that must never be overlooked.
“The reality is that pH is not always a true indicator of soil calcium availability. This is why gypsum can be used effectively as part of a fertiliser application programme.
“Salt should be applied to grassland, particularly those swards that have received high potash applications, in order to improve forage palatability.
“I recommend an application of 50kg/ac in the early summer period. Spring grass is inherently palatable.”