ASSESS MAIZE CROPS NOW FOR HARVEST READINESS

Farmers are being urged to get into fields and assess maize crops for readiness considering current hot, dry conditions could bring harvest forward by 2-3 weeks.

Although there’s huge crop variability depending on location, Amanda Clements from Volac says the summer’s record-breaking heat waves mean every crop in England and Wales will likely be ready for harvest earlier than usual.

“There’s pressure to make the most of every tonne of maize considering grass silage stock are already low because of the drought. Plus, some missed the window to make wholecrop cereals due to rapid maturing during the heat,” she explains.

“Maize growing costs are also high at around £600-900/acre and it’s unlikely to be a bumper year, so the focus should be on routinely assessing crops to ensure they’re harvested at the right time to optimise nutritional value and clamp fermentation.”

She advises the following:

1. Don’t harvest by calendar and get into fields to assess the crop

Don’t assess crops from the road, get out of the cab and into the field. “With the heat, you’ve got to keep your fingers on the pulse as crops can quickly reach maturity,” Ms Clements says. “Get away from the headland and check the crop every other day from mid-August. That time input is nothing considering the crop’s value. Generally, you see about a 2% uplift in dry matter per week, but that can accelerate to 6-8% in hot conditions so every day counts when aiming for optimum maturity.”

2. Look at 10 representative cobs

Take 10 representative cobs from 3-4 different locations across the field, about 15-20 rows from the headland and away from tramlines. Peel the leaves back from the cob and push a nail into the kernel halfway down. It should feel like soft cheddar, which will give you a few days’ grace with harvest. If you can’t get a nail in, it’s too late.

“Snap the cob in two and assess the milk line,” Ms Clements adds. “Ideally, a quarter of the kernel should be pale and milky, and a third dark yellow or converted to starch. This will be around 30-35% dry matter, which is optimum for digestibility.”

3. Check the maize plant

Look at the plant itself. There should be some die-back on the lower leaves, but the upper leaves should be green. If the plant is brown, it’s been left too late. Take 10 plants and snap them in two. Ideally the plant should feel spongy. Be aware that in newer varieties, the cob can be ready, even if the leaves are green.

4. Use a silage additive to safeguard crop quality

It is likely that crops will be drier, which means they will be harder to consolidate in the clamp, raising the risk of heating and nutrient losses. The “sweet spot” is around 30-32% dry matter, anything over that will increase dry matter losses at the clamp shoulders and reduce starch digestibility and thus ration efficiencies.

Ms Clements says the fact there’s been no rain also means the crop hasn’t had a good wash and there could be higher levels of bacteria and moulds.

“You need fermentation to drive a rapid drop in pH in the clamp and preserve crop nutrition, but the fermentation process needs moisture,” Ms Clements explains. “That’s where a heterofermentative additive, like Ecocool can help you take control of that process by producing lactic acid to drive efficient fermentation and a rapid drop in pH to help stop the proliferation of undesirable bacteria. Acetic acid production also helps to knock most yeasts and moulds on the head or make it a difficult environment for them to thrive, helping to prevent heating at feedout.”

>> For more information on best practice maize ensiling, visit cuttoclamp.com