How radishes and oats helped a Norfolk farm grow bigger sugar beet
PUBLISHED: 09:34 23 October 2018 | UPDATED: 09:34 23 October 2018
An East Anglian farmer believes cover crops have boosted his sugar beet yields by up to 15pc during a difficult growing season.
At the Thelveton Estate near Diss, about 75pc of this year’s 175 hectares of sugar beet were preceded by a cover crop of radish, oats and vetch – a mix designed to hold nutrients in the field during the winter, while the plants’ roots improved the structure of the soil.
And there are distinct differences in the size of the resulting beet, compared to neighbouring fields of the same seed variety, soil type and drilling date which were ploughed instead to prepare the ground.
Farm manager Oliver Scott said the cover crop and minimum-till approach had mitigated the effects of this year’s extreme weather, preventing soil erosion and nutrient run-off during the wet winter, while creating a soil structure which held vital moisture to help the crop during the dry summer.
“I think these beets will be 10-15pc better yields than the field next door which was ploughed,” he said. “That crop is a lot smaller and it has just not been able to thrive, whereas this crop is still growing.
“There is more moisture in the field because of the cover crop, definitely. This field will have had no more than 50mm of rain since it was drilled.
“With the radish and oats and vetch you get different levels of roots. Just growing the radish by itself is good but it only works at depth.”
Mr Scott said he has introduced more cover cropping in a bid to drive up average yields at the estate, having explored their benefits at his previous role in north Norfolk.
“It was about trying to get away from ploughing too much land, and doing more min-till, while having something in all winter to hold all the nutrients,” he said.
“Before this year we cover cropped 25pc of our land and this year, for autumn 2018, it was the other way around – we ploughed 25pc and the rest was cover crops.
“We are increasing it year on year, and we are finding the land is starting to behave a bit better.
“It is much more environmentally friendly. We are not far from Frenze Beck which washes into the River Waveney. If this field was ploughed there is no doubt it would have washed into the Waveney, because the spring was so wet.”
Paul Brown, eastern technical adviser for specialist crop supplier Kings, said the seed cost for the cover crop was about £35 per hectare, but saving ploughing costs in a min-till system had become an important driver for farmers, along with the environmental benefits.
“The resurgence of cover cropping eight or nine years ago very much started in Norfolk in front of sugar beet, with the main desire to capture nutrients,” he said. “If we didn’t have something in the field here over the winter all the nutrients will run off into the River Waveney, and that is not where we want the nitrogen to go.
“But saving costs and saving ploughing has probably become the most important part of it.
“The benefits are not so clear to some people because you don’t see a direct payback. If they pay money for a cover crop seed they have not got a crop to sell at the end of it. So it is not easy for people to see where the payback comes. But seeing is believing.
“We have seen a 20pc increase in cover crop activity every year for the last five years. Soil health and water quality are ‘public goods’, so there might be even more incentive towards this, depending on how the new system goes [in the government’s post-Brexit farming policies].”