Variable rate sugar beet drilling could improve yields and cut costs, and one west Norfolk grower is investing in the technology to do just that.
Sugar beet seed costs are about £200/ha, depending on variety and seed treatment, and represent a significant proportion of input expenses.
This prompted Strutt & Parker’s Richard Means to investigate the possibility of varying seed rates to achieve optimum plant populations and save seed on his own farming operation.
“If we can be more efficient with our use of sugar beet seed we think it will pay dividends, both in terms of yield and costs,” says Mr Means, a partner at Strutt & Parker’s Farming Department in Cambridge and who also farms in his own right.
He is planning a field-scale trial of around 20ha next spring to test variable seed rates on his own fenland soils at Oaks Farm, Outwell, five miles west of Downham Market in Norfolk.
“We will hopefully get a more uniform plant population, which will result in higher yields,” he says.
Sugar beet growers typically aim for around 90,000-100,000 plants/ha as an optimum plant population, but when soil types vary across a field this is rarely uniformly achieved.
Light soils tend to give better, more even, establishment, with the opposite applying for heavier land.
Subsequently, blanket seed rates can have a detrimental effect on the final yield of the crop, producing variable plant populations depending on soil types.
Therefore, a variable-rate seed system aims to reduce the seed rate on lighter land where there is good plant establishment, and raise rates on heavier ground where establishment is poorer.
“Sugar beet cannot tiller or branch like wheat or oilseed rape, so where establishment is known to be poor, upping the seed rate will help maintain the correct populations,” Mr Means explains.
Conversely, if populations are too high there is too much competition for space, light and nutrients and the crop won’t reach its full potential. In addition, beet harvesting can be a struggle with high plant numbers.
Mr Means has invested in a Vicon Unicorn precision drill, complete with a John Deere GreenStar GPS system with auto-steer on the company’s StarFire 2 signal.
Frontier’s precision farming division SOYL maps variations in soil types across his fields and produces a zonal map that can be divided into various target seed rates.
“Using historical knowledge of how sugar beet crops have performed we can manually tweak rates if we feel it’s necessary,” says Mr Means.
Automatic seed rate
The map is then fed into the GreenStar system via a memory card and the system will automatically adjust the seed rate of individual seed cells to correspond with the various “zones”.
Typically, the maps have produced target rates of around 110,000 seeds/ha.
Mr Means will be trialling the system on his Norfolk farm as part of the 130ha of sugar beet he grows to fulfill a 9,000t contract on his own and a neighbouring farm.
A control strip will be drilled at a standard rate across differing zones to carry out a visual and hand-dug yield comparison to assess the advantages and disadvantages of the system.
As with all trials, Mr Means says it will interesting to see if there are any significant differences in yield or cost savings and says this is the type of technology he wants to be embracing to try and squeeze out yield increases.
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