Maize Watch: Careful analysis of maize dry matter needed

Assessment of maize dry matter (DM) is being hampered by continued dry weather in many regions, according to Neil Groom of forage specialist Grainseed.

Contractors are busy cutting in many eastern areas, where on-board samples are showing high DM content, as the plants do not contain as much moisture in the stems and leaves as normal, says Mr Groom.

“Growers are determining harvest timings on grain maturity, measured as cob ripeness, as it is the starch content from the grains that drives production over the winter,” he says.

See also: 6 top maize growing tips to help livestock producers

He has seen crops test at 30% DM because of their dry stems and leaves, while the grains are still only milky-ripe. These crops have been left longer so the starch can fully mature.

Toby Tibbenham, who is sampling for Farmers Weekly, grows maize for energy on his farm near Harleston on the Norfolk-Suffolk border.

He is delaying harvest until the grain is hard and mature (see “Progress of maize crops on six sites in England, Scotland and Wales, 2022 growing season”).

“Last week’s FW dry matter was 29.7%, but the crop was green and the grains milky-ripe. It was just that the stems were so dry,” he says.

Chop length

By shortening the chop length, Mr Groom says good consolidation in the clamp is still possible, as long as the silage in loaded into the clamp in shallow layers with repeated rolling.

Any fields with a lot of dried leaves should be harvested first, especially if the grains are also very hard, he advises. This ensures the silage has plenty of time in the clamp before being fed to allow the grains to soften and become more accessible to rumen bugs.

Cutting greener fields last so they are on top of the clamp will also help overall consolidation and reduce spoilage on the top of the clamp, he suggests.

Wetter areas

Growers in the West and North, where more rain has fallen over the summer, should also look at their crops early this year, says Mr Groom.

“We have had more heat units throughout the summer and crops are further on than normal.

“Many regions will be cutting in September if the crops were drilled in April, which is ideal, as field conditions are likely to be drier, days are longer and it will be an easier and safer harvest.”

He recommends covering all clamps with an oxygen barrier silage sheet to reduce surface spoilage. Ideally, the walls should also be covered so the clamp is completely sealed. This will ensure a fast and efficient fermentation.