Later maize sowing’s no bad thing for good yields

Maize sowing may be delayed this year due to late frosts and heavy rainfall in some parts of the UK, but that may help rather than hinder crop yields.

Advanta Seeds’ technical trials officer Lindsay Cousland believes this spring’s frosts will have made for ideal seed-beds, although wet conditions in some parts will still be holding back soil temperatures.

“However, there is still no rush to plant maize.

And most crops, providing variety choice is suitable, will benefit from a later planting.”

Results from Advanta’s own trials comparing crops sown across a range of dates, from early April to the more conventional early May, suggest May sowings fare better.

“Sowing early can actually hinder plants, as they can be caught by late cold snaps and never recover sufficiently.

“Also, early sown crops often fail to make best of the UK’s growing conditions, being too far advanced to make best use of warm weather in July.

Early crops are often flowering in July, so are unable to use the warmth and sunlight to best effect.

May plantings are able to use this prime growing weather to add bulk, improving overall crop yields.”

Mrs Cousland says in Advanta’s trials later sown maize crops have yielded on average 2t/ha more than crops sown in early and mid-April.

And while some farms may aim for an early drill date to ensure an early harvest, she believes the advances made by maize breeders in the past decade negate this.

“With correct variety choice, most growers should be able to harvest May sown crops by the end of September when field choice is correct.”

Meanwhile, Maize Growers Association agronomist Simon Draper advises growers to hold back from sowing until soil temperatures are suitable.

“But as soon as soil is consistently above 10C crops should go in.

Where soils are still wet at drilling seed rates should be increased by about 5%.”

While this may differ from the conventional theory of reducing seed rates to ensure an earlier maturing crop Mr Draper says growers need to allow for seed losses.

“And crops should be drilled quite shallow to avoid disturbing cold, damp soil further down.

Where seed losses to birds are an issue it should be drilled at about 2in down to minimise losses.”

For Steyning, West Sussex, grower Tim Gue this season will be one of the latest in recent memory, with drilling delayed until yesterday (20 April).

“We would generally aim to start drilling about a fortnight earlier, to maximise the growing season.”

Being on a particularly favourable site Mr Gue believes earlier sowing lets him maximise yield and ensure a reasonably early harvest.

“This year harvest will probably be delayed by about a week, potentially clashing with arable crop drilling.

Although this year’s choice of slightly earlier varieties should help overcome some of these issues.”

Mr Draper also recommends starter fertiliser, as this will give crops about one week’s head start over those sown without it. “For some marginal areas this could be crucial in a late season like this.”

Undersowing crops with grass and clover when they are at the four-leaf stage can also help avoid any cross-compliance issues, adds Mrs Cousland.

“This means harvesting traffic is running on grass rather than bare soil, helping limit the amount of soil carried off fields and limiting chances of run-off.”