Understanding the effects of delayed germination and poor nutrient uptake caused by drought stress could help maize growers unlock further yield potential for the crop.
With spring and early summer droughts becoming more frequent in recent years, changes in maize management could be needed for livestock producers seeking to secure adequate winter silage, says Wilson Hendry of forage specialists Grainseed.
Although Met Office data shows last summer had 7% more heat units between May and September than the 30-year average, lack of rainfall at critical times of the year stopped this translating into bumper yields on many farms.
“The early advantage in terms of heat units was gained in early summer with May over 20% ahead of the average and June over 12%,” says Mr Hendry.
“All maize growing areas experienced above average Maize Heat Units (MHU) with Southern England, East Anglia, the South East and Central England achieving over 1400 MHU – significantly more than the minimum 1200 needed for maize.”
Early dry conditions were compounded by low rainfall at critical times. Most areas suffered a real lack of moisture in May which caused widespread germination issues, especially on those difficult seedbeds on heavier land where drilling seed into moisture was almost impossible.
“Delayed germination and drought stress slowed plant progress with lack of access to N, P and K definitely playing its part.”
With drought stress appearing to be more of an annual occurrence, especially on lighter land in lower rainfall areas, growers need to factor this into their future crop management to mitigate against its effects, he says.
“The starting point is to take the possibility of drought conditions into your varietal choice decisions. If you’re in a drought-prone area, it’s worth taking a look at some of the more drought tolerant varieties like Marco and Crosbey.
“Both of these can be drilled on sand and gravel and, if grown at lower seed rates, which helps to optimise the available moisture, Marco can produce two cobs per plant so starch yields can be up there with the best.
Increasing organic matter in soils can definitely also help so you need to be thinking of making as much use of FYM manures, digestate and composts. Preserving moisture should also be a priority when thinking about your cultivations, he advises.
“Maize hates compaction so if you have a problem with this, then subsoiling will be needed. You need good seed to soil contact so a relatively fine seedbed has advantages but you need to be careful not to overwork soils.”