The cold, wet start to March means growers must be patient when it comes to spring drilling, otherwise crop establishment could be severely compromised, leading agronomy firm Hutchinsons warns.
Experience shows the best spring crop yields in the northeast tend to come from mid-March drilling, but that timeframe is likely to be delayed this year and there is no sense rushing in, says the firm’s Yorkshire-based agronomist Robert Barker.
“Soil temperatures in this area are currently below the March average of around 5.5C and are too cold for drilling. Winter crops don’t generally start to move until soils reach 5C upwards, so ideally that would be the minimum temperature for spring sowing.”
But, while warm soils will boost germination and early growth, temperature should not be the main driver for deciding when to drill. The bigger issue is soil moisture, he says.
Melting snow from earlier in the month combined with rain since then has left many areas saturated and far too wet for land to be worked. Mr Barker urges growers to wait for underlying soil conditions to dry out sufficiently before going in with the drill or cultivating land not prepared last autumn.
“On heavy land in particular, you can soon do a lot of damage by working soils when they’re too wet, which will prevent spring crops rooting properly and may cause lasting structural damage. It’s not just about drilling, conditions also have to allow you to get land rolled and fertiliser and pre-emergence herbicides applied straight away.
“Spring crops have such a short growing period, once they’re in you can’t afford to let anything impede growth, as yield potential will be dramatically reduced.”
Every field should be judged on a case-by-case basis, but generally soil conditions dictate when to drill. Providing soil temperatures are rising with no cold spell or severe frosts forecast, then it is best to get crops in, Mr Barker adds.
Young bean plants in particular will be adversely affected by frost after emergence, but so too can barley seedling and peas. Beans also struggle if they are sat in wet soils, so although they are often regarded as a more robust crop, he says it is still worth waiting for the right conditions for drilling.
“In Yorkshire, growers will drill spring crops late into April, but yield starts to be limited from 1 April, so it can be a tricky balance to strike.
“Generally, though, the best crops are drilled in good conditions with nothing to impede roots and warming temperatures.”
Mr Barker notes that seed rates should be tailored to soil type and establishment conditions, but suggests higher rates are often necessary on heavy land. Spring barley seed rates of 400-450/m2 are common practice on heavier soils and higher rates are used in some areas. More caution is needed when using higher seed rates in crops like oats due to challenges with lodging and specific weight.