Ask The Kernel - Get ready for maize sowing
Ask The Kernel is here to answer your questions on all aspects of maize growing – from field to feed.
Ask The Kernel kicks off some of the pertinent questions before the crop gets in the ground this season.
How important is soil and seedbed preparation for maize drilling and establishment?
“Maize roots are extremely susceptible to any soil structure issues, be that shallow soils, pans or cloddy sub-soils. The first step is to get out and dig with a spade, to understand your soil structure and identify any issues.
“Subsoiling can bring about dramatic improvements for maize, but does need to have been done in advance and when the soil was sufficiently dry to achieve the desired shattering and pan busting.
“Key is to wait for the right soil conditions for cultivations in the spring, and not try to force a seedbed if it is too cold and wet.
“Furthermore fine level seedbed preparation is also important for effective herbicide control and to ensure maize emerges rapidly into a clean surface.
“Using an angled spray nozzle has proven valuable to achieve all round coverage of the surface. New pre-emergence herbicide trials have shown application at 200 l/ha water volume has given very good results.
“A level surface also helps to maintain an even boom height of 50 cm above the soil surface, whilst operating at 10–12 km/hr. This will achieve more consistent coverage and optimum results.”
How deep should maize seed be placed?
“Maintaining a consistent sowing depth is crucial, if we are to get all the seedlings to emerge together. Whilst early weed control is clearly important to prevent competition, maize plants will also compete with each other, and if one is at the two-leaf stage before its neighbour appears then the last ones up will always be at a disadvantage.
“Sowing faster than the drill’s capacity can also influence seed distribution in the row, so again check and check again in each field; slow and steady generally wins the day.”
What about seed rates and row width?
“Whilst row width will frequently be set by existing drill equipment or the farm’s contractor, it’s worth noting research has consistently reported higher yields from 50 cm row spacing, compared to conventional 75 cm spacing.
“Three successive seasons of trials in France showed a gain every year, and an average 12% adjusted yield improvement, from sowing at 130,000 seeds per hectare in close rows, compared to conventional 100,000 seeds at wider row spacing.”
Download a copy of the Maize Growers Association 2018 Conference Question Time panel answers, chaired by John Morgan (inset below) and sponsored by Ask The Kernel. Click here or on the image below.
When should we start sowing?
“The old adage has been to sow maize once soil temperatures reach 10°C, but a more accurate measure would be to monitor soil temperatures at a sowing depth – and to plant once that reaches a stable 8°C or more.
“It’s worth noting that temperatures can vary considerably from field to field, according to soil type and aspect. Start with lighter soils on south facing slopes and work through to colder soils later. Be aware of frost pockets or hollows that could drag down emergence and overall field performance.”
Should we use a starter fertiliser at drilling?
“First step must be to analyse what soil reserves are present, and accurately assess how much nutrient has been applied by way of organic manures that will be available to the crop.
“Phosphate is relatively immobile in the soil. Therefore, if it is to be used, accurate placement of balanced nutrients designed to invigorate root growth beside or just below the seed, where it will be readily taken up and utilised, could prove beneficial.”
Come back for more updates and questions from Ask The Kernel as the season progresses.....