In the final article in our Maize Matters series for 2016, experts are upbeat about prospects for this year’s crop, with predictions both yield and quality will hold up well compared with previous seasons.
A late spring but an early finish is how John Burgess of KWS describes the growing year. He says crops have caught up following the cold, wet conditions which delayed drilling on many farms. He anticipates many dairy farmers will be pleased with the ‘rocket fuel’ stored in their clamps, although he advises those with crops still in the ground to exercise caution.
Mr Burgess says: “A number of maize crops hit 30 per cent dry matter while they were standing at the beginning of this month (September). This figure could rise to as high as 36-38 per cent by the time some material is harvested, so extra care will be needed during the cutting and ensiling process.
“A crop which is too dry will spring back when it is compacted in the clamp, so cutting shorter will help to alleviate this problem. However, a longer chop length will increase the ‘scratch factor’ which dairy farmers are looking for, so decisions will have to be made on an individual farm basis. On the plus side, concerns about effluent run-off are unlikely to apply to this year’s crop.”
A brief consultation with the contractor may prove to be beneficial, for crops designated for cattle feed, he adds.
“This year we have three factors to consider; farmers are tending to favour early varieties, the season is early and there is not much time in which to complete harvest. Therefore, the risk of whole kernels entering the clamp is at its highest.
“If kernels are not smashed effectively, then by-pass starch levels will be reduced in the end product and the silage will be difficult to handle in the clamp. Therefore, corn cracker settings must be correct, even if this means accepting a slightly lower rate of output.”
A somewhat different picture emerges for the north of England. Steven Gate of Agrovista forecasts ‘huge’ yields for maize in the region, but warns some crops are far from ready. He urges patience before cutting, in order to maximise quality.
“Maize plants have reached heights I have not witnessed for at least six or seven years and maize under plastic has performed exceptionally well,” he says.
“But it is important to wait until dry-down. The starch percentage is diluted in a large plant, so harvesting should be delayed until the ‘magic’ figure of 28 per centplus dry matter has been achieved throughout the material. This includes the cob, which contributes half of the crop’s final dry matter value.”
To test maize for readiness, a representative plant should be taken up and twisted at around the second node, he says.
“If liquid resembles water dripping from a tap, it is a sign the crop is too green. It will only be ready at the stage when just a couple of drips are produced, in response to twisting.
“To check the cob, split a couple of samples two thirds of the way along, using a fingernail. Kernels which are prised open will indicate their readiness when no liquid emerges after pressure.
“In some areas, Cumbria in particular, the grass silage harvest has been generally favourable, so there should be no need to sacrifice maize quality and put the fermentation process at risk by cutting the crop before it is fully mature.”
He recommends using a biological additive at full rate to reduce the risk of secondary fermentation.
“Maize cut this autumn may have to be stored for as long as 11 months, so stability in the clamp is vital. An additive will help with this process and I usually advise applying a liberal quantity of agricultural salt around the clamp shoulders, to seal the edges and minimise aerobic spoilage,” says Mr Gate.
In the South West, Mark Smyth of Agrii says crops got off to a good start and never looked back.
“As always, seedbed preparation and paying attention to every detail of crop management has paid dividends and growers have become very sophisticated in the way they manage their maize.
“The one area which can let farmers down is the over-reliance on organic manures. If they are valued too highly, then disappointment can result; the aim should be for a total of 150kg of nitrogen/ ha to be applied to maize fields. It is a good idea to consult the RB209 handbook, to get an approximation of values or, better still, have samples analysed before spreading.”
With temperatures in the southwest region having exceeded 30degC in the vulnerable period, eyespot has not been a concern and weeds were largely kept at bay during the generous windows that the fine weather permitted. Mr Smyth concurs with other industry pundits, who strongly advise waiting until the crop is fully ripe before cutting.
“When assessing the crop, walk right into the field and examine plants at several different locations, avoiding the edges, which will not be representative” says Mr Smyth. “The stover and stem are the most important indicators and cutting should begin only when they have reached a dry matter of about 24 per cent. A good indicator is when the leaves which are level with the cob are beginning to go brown, while the top leaves are turning pale and papery.”
He advocates using the ‘taste test’ method. “The cob grains should have a nutty, slightly sour flavour, which indicates the sugar has been transformed into starch,” he says. “If it tastes sweet, it is likely that it is not yet ready to harvest.
“We are fortunate crops are maturing ahead of average times, so there is plenty of opportunity to wait for the right conditions. This is in stark contrast to other years in recent memory, when the harvest period has been challenging, to say the least.”
crops can take advantage of the free, online KWS maize heat units service. Entering the farm postcode will produce a figure for 2016 heat units in the region, with the figure updated weekly and compared with the long-term average.
Early varieties (FAO 150-160) require 2,100 heat units to reach maturity, with a figure of 2,400 for later varieties (FAO 180-210).
Late-maturing energy hybrids (FAO 240-260) for biogas require 2,500-2,800 heat units, depending on drilling date.