As leaving maize stubble fields bare could risk failure to meet cross-compliance, more growers are recognising cover crops could prove a worthwhile option.
Growers who have identified fields as being at risk from soil erosion could also be at risk from failing to meet cross-compliance criteria, warns Promar International consultant Derek Gardner.
“When you tick the box on the SP5 form identifying fields as liable for soil erosion, then leaving stubbles unworked is not an option.”
A catch crop that can establish quickly, hold the soil and soak up any surplus fertiliser is worthwhile to the environment as well as offering a spring crop, reckons Salisbury-based seed merchant David Bright.
He advises using agricultural mustard, Italian or Westerwold ryegrasses, which can all be spun on the surface.
Grasses are quick to establish and will provide useful early spring growth, adds Mr Bright.
“At a seed rate of 30kg/ha, ryegrass will cost about 43/ha.
“Sown at a rate of 7-10kg/ha and costing about 7/ha, mustard can reduce soil run-off and soak up fertiliser.”
Having provided a good green cover throughout the winter, Mr Bright estimates mustard is worth the equivalent of 125kg/ha nitrogen.
One farmer sowing mustard for the first time into 57ha (140 acres) of maize stubble is Graham Luff, Petersfield, Hants.
“The aim is to prevent soil erosion and water run off.”
For environmental reasons, he is not keen on leaving ground bare and intends to use the cover to obtain points for Entry Level Scheme.
Independent consultant John Morgan says where plenty of manure has been spread, also consider growing a cover crop, as nitrogen tends to be released now and is wasted in an empty stubble field.
“But catch crops must involve cheap establishment with minimum machinery,” reckons Mr Morgan.
And, when grass is used between maize crops, be ruthless with cutting dateto drill maize early.
“There is also the risk that when dry grass is cut in April, the ground remains dry for maize establishment.”
In this instance, he advises grazing any grass so moisture can be returned from cows.
When perennial weeds are a problem in cover crops, MGA agronomist Simon Draper advises using glyphosate to burn them off before spring ploughing.