Maize is very popular but mounting concerns about soil erosion associated with the crop are causing some to re-evaluate it
Maize has long had a reputation for being tricky to handle. A valuable feed source for pushing both milk yields and DLWG in beef cattle, it also contributes to significant run-off and erosion. This not only causes sedimentation and nutrient loading of our watercourses but, also important for the economics of farming, the loss of valuable topsoil and resulting criticism from the non-farming community.
The primary cause for all this is the long-held requirement for maize to be planted in a well-cultivated seedbed, traditionally achieved by deep ploughing, sub-soiling and power harrowing. This results in a fine seedbed, which is largely left bare during the growing season, as the maize plants are planted on wide rows. Where the rotation requires maize to follow maize, the land is left bare over winter following a late-season harvest. All this leads to compaction and damaged soil, which is liable to run off and erode.
Improving the environmental footprint of maize
With the value of maize as an energy source beyond doubt, it is important to find a method of establishment and ongoing management that addresses these issues.
Enter James Lee, an agricultural contractor from Crediton, Devon. Understanding the need to improve the environmental footprint of maize—and having had great success in reduced cultivation cereal establishment with the Claydon system—James set about designing a ‘strip till’ system that could be used in maize.
The system consists of an opening disc that cuts through trash and reduces soil throw from the following leg, helping to remove compaction at depth. Behind that, there is a set of three intermeshing discs which cultivate a strip that is then consolidated by a set of prism rollers. The cultivator is set to 50cm row width, the hope being that this will encourage taller, more competitive maize and reduce the bare ground in between the rows.
Starter fertiliser can also be placed precisely in the cultivated strip behind the leg, giving the maize the required nutrients exactly where and when it is needed.
Once the cultivator has been through, the ground is left for 24hrs to settle and then a conventional maize drill, set to 50cm rows, follows the same track to drill the seed. By only cultivating the strip into which the seed will be planted, a large proportion of the soil is, in effect, left uncultivated. This not only reduces the costs and HP requirement of establishing the crop, but also increases the infiltration rate of the soil and so reducing the likelihood of water running off. It also helps maintain organic matter levels in the soil, improving water holding capacity and trafficability come harvest.
It is also hoped that better soil conditions left after harvest will allow the timely establishment of a winter cereal or a cover crop if maize is the following crop in the spring.
The system has been under development for some time and James was able to undertake some trials work last planting season with encouraging results. “Last year’s initial trial was late going in the ground,” says James. “But even planted at the end of May it still yielded 18t/ac.”
SWFC are looking forward to seeing how the system runs in trials this season. Look out for further information later in the year.