Maize Watch: Advice on reducing soil erosion post harvest

Initial maize yields look good, with big cobs which have matured well and green leaf still on the plants, latest Maize Watch growers report.

Good weather has allowed harvest teams to start chopping maize with sites in the South East and South West having already started harvesting.

Advice for harvest:

  • Check your crops twice a week as you near harvest since dry matter will increase by 4-5% per week when its warm and windy
  • Target a crop dry matter of 32-36% so that starch yields are maximised and clamps can be consolidated well
  • If the crop becomes very dry chop your maize shorter (10-12mm) instead of the normal 18-20mm to help consolidation in the clamp

George John, sampling for Farmers Weekly near Narbeth, in South Wales, says his early-sown crops are only three weeks away from harvesting.

 “Our sample field was later sown, but the maturity class 9 varieties sown around 20 April are really good, with very firm grains and just starting to dry back from the stem base.”

He estimates yields will be around 16-17t/acre with sheltered spots doing better.

“In a year when we have so much grass silage we need the maize to make a good winter diet.”

Advice for post-harvest

Once harvested, maize stubbles should be ripped up to remove the wheel markings from the forager and trailers, advises Neil Groom, technical director for Grainseed.

“Soils are still warm and fields should be planted with winter cereals, grass seeds or cover crops to ensure that nutrients are captured and soil erosion is prevented,” he adds.

A simple tine will open up the soil surface and allow rainfall to soak into the soil rather than running off across the field taking your soil with it. Seed can then be sown and within two-to-three weeks the field could be green and building organic matter.

See also: New maize varieties revealed on BSPB’s annual list

Work by North Wyke showed that water run-off down a slope reduced to just 1 litre where the field had been cultivated across the slope.

Mr Groom says this should be standard practice on all overwintered stubbles if a crop is not sown.


Drill date

Height above sea level (m)

Crop dry matter 11 September

Increase from last week

Petworth, Sussex

28 April




Harleston, Norfolk

2 May




Crediton, Devon

29 April




Ticknall, Derbyshire

10 May




Narbeth, S Wales*

10 May




SRUC, Dumfries, Scotland PLASTIC

17 April




* Variety Es Picker, all other sites are Es Ballade. Variety under plastic Es Marco