The full potential of forage maize is now being realised

Despite all the madness of the extreme weather that was the summer of 2023, growers are currently harvesting fields of maize that are yielding between 18t and 21t of fresh weight per acre.

It’s an incredible success story, particularly given the very disappointing performance of spring barley this year.

Meanwhile, demand forage maize has never been higher.

Local dairy and beef are now keen to include it within total mixed rations the year-round. In addition maize is the perfect forage source for anaerobic digestion (AD) plants.

From an agronomy perspective, maize tacks many boxes. In the first instance, there are no repeated visits to fields throughout the growing season. It’s a case of getting the crop in during the spring period and then coming back for the harvest in late September: early October.

This is particularly the case when maize is sown out on ground that was previously in grass. The crop is also an amazing sump for animal slurries. Surely this has got to be part of Northern Ireland’s response to the nitrates’ challenge.

For specialist arable farmers, maize can work at a number of levels. They can grow the crop as a direct cash option, selling it direct from the field at harvest.

Or they can grow the crop as a bespoke contract arrangement for dairy or beef farmers.

Given the returns available from forage maize, it is the one crop option that will allow bespoke tillage farmers to compete directly with milk producers for rental ground.

As far as I am aware, forage maize is not eligible for the tillage incentive scheme. This situation must be changed in time for the 2024 growing season.

Forage maize will never replace barley as the main spring cropping in Northern Ireland. The year that was 2023 threw up some very unique challenges for barley growers.

However, the scope to increase the maize acreage grown in this part of the world is immense. And arable farmers can lead the charge in this direction.

The reality is that livestock farmers – and many contractors for that matter – do not have the equipment and agronomy-related skills to ensure that crops of maize get off to the best possible start. In contrast, tillage farmers have this skill set in abundance.

Forge maize: maximising yields

Getting seeds down to the right depths is one of the key requirements when it comes to successfully establishing crops of forage maize.

Maizetech’s John Foley, takes up the story:

“Seed should be placed at a depth of around 2”,” he added.

“Seed that drop on to the surface can cause problems when they are covered with a layer of plastic.

“In the first instance, birds cannot get at them. So they will germinate and cause problems for the other plants coming up from below.

“A planting depth of 2” is required to allow maize seed establish a strong root system. This cannot happen if they are at or just below the surface.”

Foley went on to point out that the recommended fertiliser requirements for maize crops are fast changing, particularly where potash (K) is concerned.

He commented:

“Up to now the thinking was that 60 units of K per acre would meet full crop requirement. This is now recognised as a very inadequate figure. The total potash requirement for maize is actually in the region of 200 units/ac.

“Animal slurries are very valuable sources of potash. However, these tend to be ploughed down to depths of 8” prior to planting.

“This means that freshly germinated maize seeds are coming through in what can only be described as a potash deficit environment.

“As a result, it is now strongly recommended that additional, bagged potash is placed with the seed at time of planting.”

Foley is very aware that bringing heavy machinery on to land during the month of October can lead to soil compaction problems.

“But this will only be an issue at headlands,” he commented.

“And it is these areas of fields only that should be sub-soiled after a maize crop has been harvested.

“It is important that fields of maize should be completely harvested at the one visit, if this at all possible.

“The fact is that mature crops of maize are drawing large volumes of water from the soil while the plants are alive.

“However, if heavy machinery is brought across stubble on a second occasion, in order to finish the harvesting of a crop, significant compaction problems will arise across the entire planted area.”

According to Foley, maize crops are increasing in dry matter at a rate of around 2% per week at the present time.

“Starch values are increasing at a similar rate,” he confirmed.

“Approximately 50% of the dry matter within forage maize is contained within the cobs.

“Crops can be harvested when the leaves directly adjacent to the cobs start to turn pale in colour.”

When to harvest maize

According to John Foley, forage maize crops should be harvested when cobs reach 50% dry matter. This growth stage can be discerned when the leaves adjacent to the cobs start to turn white.

He added:

“At that stage dry matters in the rest of the plant will be in the region of 22%. This means that the forage going into a clamp will have an average dry matter value of 32%.

“Under these circumstances the amount of effluent produced will be minimum. So a fresh weight will equate with the final feed-out value.”

Foley is also confirming a 25% year-on-year increase in the area of forage grown here in 2023.

In addition, this year has seen the wide scale use of new, compostable film at planting.

John further explained:

“The new films are acting to deliver enhanced growth rates for maize crops. They will decompose fully within six weeks of initial use.”

One slight downside to the use of the new films is the restriction they place on planting dates.

John Foley again:

“We have been advising growers not to plant maize before the end of April.

“As a result, there will a very high proportion of this year’s maize crops coming to maturity within a relatively short period of time.”

The Maizetech representative is also conscious of the deterioration in ground conditions that has impacted across the country over recent weeks.

“But there is no need for growers to panic,” Foley commented.

“There is still plenty of time to get crops harvested.”

Farmers are being advised to take a strategic approach when it comes to the use of an inoculant on forage maize crops.

According to Foley pits of silage will remain stable for months, without the use of an inoculant.

He added:

“Stability issues might arise if maize is taken from a pit during periods of warm weather.

“Many livestock farmers will not open a pit of maize until the spring months. If temperatures rise above 18°C then the forage will start to heat up if an inoculant had not been added at time of ensiling.

“I regard an inoculant as a form of stabiliser.”

North Co Armagh dairy farmer, Mark Lewis, recently hosted a College of Agriculture, Food and Rural Enterprise (CAFRE) business development group meeting.

The focus of the event was the growing and utilisation of forage maize within a milk production business.

In 2022 Mark grew 18ac of maize for the first time. The area increased to 23ac this year.

On the back of last year’s crop Mark was feeding the maize at a rate of 10kg/cow/day from November through to the middle of the summer.

He found that while the maize was included in the total mixed ration offered to the cows, gut health improved, as did fertility.

Mark commented:

“The plan now is to offer maize to the cows the year round. This is why I have increased the acreage of the crop grown in 2023.

“Last year the maize was ensiled in a clamp with one earth banked wall. Spoilage was noticeable at that point in the silo as the feeding season progressed.

“For the coming season, a new wall has been built to replace the earth bank. The breadth of the silo face has also been increased from 22’ last year to 29’ at the present time.

“I am aware that exposing more of the maize to the air, particularly as the weather warms up in the spring and summer months, can lead to heating of the forage.

“However, the plan is to use enough of the silage on a daily basis to prevent this from happening.”

CAFRE dairy advisor, Alan Hopps, had prepared figures for the meeting which compared the costings of growing forage maize with a four-cut grass silage system.

These confirmed that maize is costing £58/t directly prior to feed out. This is assuming a 17t/ac fresh yield and a dry matter value of 30%.

The equivalent figure for the grass silage system is £67/t. This is assuming a dry matter grass yield of 4t/ha/cut.

Hopps commented:

“The big factor coming into play, where forage maize is concerned, is the fact that it is a one-harvest crop.

“But the final yield achieved by a maize crop is everything. The cost of production per tonne of dry matter ranges from £310 for a fresh yield of 10t/ac down to £170 for a 20t/ac crop.”

Following the presentations, the members of the business groups inspected Mark’s 2023 maize crops.

It was estimated that yields of between 18t to 20t/ac can be expected. The crops will be ready for harvest within the next fortnight.

In conclusion

Forage maize has the potential to be one of the very few good news stories emanating from the arable sector in 2023.

Crops have a significant yield potential. But all of this counts for nothing if they cannot be harvested safely.

But the weather and ground conditions will play a critical role in allowing this to happen.

Most arable soils are currently at, or even above, their full water retention capacities.

They need to dry out quickly. And this all comes down to the prevailing weather and soil conditions. So here’s hoping!

Meanwhile, Predicted record maize crop yields could bring higher risks of mud being left on roads during harvest NFU Mutual has warned.

The rural insurer is concerned that extra maize planted this year, with expected heavy yields, could raise the risk of mud being deposited on roads during harvest.

Hannah Binns, NFU Mutual Rural Affairs Specialist, commented: “Many dairy farmers have put more fields down to maize this year or grown the crop for the first time to counteract the high costs of bought-in feed.

“Plenty of rain over the summer has led to very heavy crops in many parts of the country, and we are concerned that harvesting these could lead to problems including mud left on roads by tractors and trailers.

“This is a particular problem with crops harvested in autumn when heavy rainfall is likely.

“We’re advising farmers harvesting maize to prepare for poor conditions by putting in place plans to use measures such as field wheel washers, warning signs and road sweepers to reduce the risk of a road traffic accident which could lead to deaths or injuries – plus the risk of prosecution.”

Other crops harvested in autumn – including sugar beet and potatoes can also lead to mud being let on roads.

Even tractors moving between fields during ploughing and other cultivation operations can also lead to large mud clots being left on roads which can prove hazardous to road users, and particularly motorcyclists.

The legal position is that farmers must take steps to prevent mud being left on the roads by their vehicles.