Could grain maize have the X factor southern England growers are looking for in a break crop? On paper it looks like a winner – margins as good as winter wheat, better than break crops, such as oilseed rape (see table).
But late harvest, soil management issues and high drying costs – not to mention a yield penalty in following wheat crops – are all fear factors for growers.
Gradually those fears are being overcome, according to Troy Stuart, FW’s south-west arable barometer farmer. He grows around 140ha (350 acres) of the crop on his own land, and contract harvests a further 160ha (400 acres). “I’m seeing an expansion with other growers.”
It is a market with potential to be home-supplied. Almost 1m tonnes of grain maize are imported into the country currently, according to Mr Stuart, but with dairy farmers, and other livestock farmers, increasingly wanting a higher quality feed source and realising grain maize’s potential, the crop’s area could be an awful lot bigger than it is now, he says.
Combining is fast at around 8-10 acres/hour. Mr Stuart uses the same Claas Lexion 600 for maize as for cereals, but with a specialist snapper header fitted. The contract harvesting allowed him to justify its £40,000 price tag.
Only the cobs enter the combine, with the maize threaded through rotary rollers and chopped from underneath by a set of blades. The only modifications to the combine itself are in the concave, where the gap between the rasp bars needs to be filled, while the straw chopper knives towards the rear of the combine are switched for heavier ones.
Contract harvesting costs are around £95/ha (£38/acre), with the option of using a chaser bin with low ground pressure tyres to reduce compaction. The late harvest date – usually into November – can mean it is easy to damage soils while combining.
Luckily this year’s harvest has been straightforward. Good autumn weather has minimised any soil damage, while yields have been good. Mr Stuart budgets on 7.5t/ha (3t/acre), but one block has achieved a best ever 4.2t/acre dry weight.
Most of his grain maize is followed by winter wheat, although it can go back into a second maize crop or other spring crops if conditions don’t allow late wheat drilling. “I usually go through with a shakerator to take out shallow compaction and then drill the wheat into the trash with a Vaderstad.”
Avoiding ploughing minimises any problems with run-off, he notes. It is also important not to dislodge the maize stalk. “That’s when you can have problems with hair-pinning when drilling.”
There is a yield penalty when drilling wheat so late, he admits. “That’s the downside – the following wheat is 0.25-0.5t/acre down, but that’s off-set by lower establishment and spray costs.”
What isn’t cheaper is drying. You’re lucky if you can cut grain maize much drier than 30%, and it needs to be dried down to 15% to store. That takes two goes usually using a continuous flow system, Mr Stuart says. “With the higher diesel costs its costing £24-25/t.”
The alternative is to crimp the wet grain, usually at 35-36% moisture content. Mr Stuart crimps a proportion of his area using a crimping machine with fluted rollers. “You need something not quite as aggressive as a corn cracker. You can’t use dimpled rollers.”
A preservative is added during the crimping process to maximise nutrient retention when ensiled and during feed out. The product, popular with dairy farmers, can be stored for up to a year in an air-tight clamp, Mr Stuart says.
All of Mr Stuart’s grain maize goes for animal feed – the majority to Lloyd Maunder‘s for its corn-fed chickens – but grain maize also has human consumption markets.
Margin comparisons (£/ha)
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|£/t (net of drying)|| |
|Annual costs|| |
|Net margin|| |