Article taken from British Dairying
The later maize harvest this season poses some challenging questions for maize growers, says Nigel Walley national seed manager at Agrovista.
A reduction in heat units avail- able to the UK maize crop of about 10% in August and 14% in September compared with the 30- year mean meant it was inevitable that this season’s harvest would be a late one, resulting in poorer quality forage, muddy roads and irate motorists. It’s not the publicity the crop needed. Maize has already be- come something of a contentious crop of late, not helped by reports by organisations such as the Soil Association highlighting issues with maize grown for anaerobic digesters having a detrimental effect on soil structure and the environment. What is clear is that as an industry we have to grow maize in an environmentally acceptable way as possible. Part of this is to look at earlier maturing varieties that enable a more timely harvest, are an entry point for a following crop and can also help establish a cover crop if needed.
Chasing absolute yield is a somewhat blinkered approach if we are compromising the follow- ing crop, creating compacted soils and annoying our neighbours with excessive mud on the road due to late harvesting. There are now plenty of earlier maturing varieties to suit all maize production sys- tems, be that for forage or energy. Ramirez is a classic example of acceptable yield and class-leading earliness and feed value ideally suited to the forage market.
For the energy sector varieties such as Hobbit are significantly earlier than some of the Continental-type varieties some growers have been encouraged to use, which are simply too late for consistent and reliable yields in the UK.
Another tool to help pull harvest dates forward is seed rate manipulation. Some growers are sowing as many as 125,000 seeds/ ha. Why? High seed rates lead to big clamps of forage but at what cost?
Low starch, poor feed-value forage has to be fed at higher inclu- sion rates than high-starch, quality forages. Higher seed rates, later harvesting, and poorer quality all mean higher growing costs. Sim- ply reducing the rate to 100,000 to 105,000 seeds/ha would cut those costs and produce better quality forage with negligible effect on yield.
Later maturing energy maize crops can be drilled down to 90,000 seeds/ha, which will enable higher starch and dry matter yields criti- cal for energy production. Prevention of erosion by timely harvesting, enabling a following crop or a cover crop to be established effectively is a key point. Growers need to be aware that areas of soil erosion greater than one hectare can lead to a loss of basic payment.
Establishing a cover crop during the growing season is not new. Drilling Italian ryegrass into three- leaf maize for sheep keep was not unheard of 20 years ago even in the days of good old Atrazine.
Maize growers need to take stock, think about their soil and the environment, choose quality over quantity and get the basics right. Matching variety to location, taking into account soil type and expected harvest date and using seed rate manipulation to further fine-tune decisions will pay dividends. Think about the overall yield of two or more seasons’ cropping, rather than compromising the future by growing varieties not suited to your farm in the vain hope of extra yield.