Farmers profit from earlier drilling of maize

Catchment Sensitive Farming officers have been working with farmers, the Maize Growers Association (MGA) and the Environment Agency to run trials across the South West looking at how we can maximise the profitability of growing maize while minimizing the risk of harm to the environment.

Maize is often harvested late in the year when soils are generally wetter and more prone to compaction increasing the risk of runoff. Heavy machinery compacts the soil, squeezing out the natural pores and fissures which are found in good soil structure. This makes it more difficult for water to soak in.

Water that isnt absorbed flows into the nearest watercourse, taking sediment, pesticides and nutrients with it. This pollutes watercourses and bathing waters. These maize trials show that it is possible to produce profitable crops and improve soil condition, said Paul Allen, Catchment Sensitive Farming Coordinator.

John Morgan, from the Maize Growers Association, said: Weve been pleased to assist with the maize trials. We strongly believe that maize has several environmental strengths, but we are keen to help farmers recognise the potential problems associated with the crop.

The trials have taken place at three sites on different soil types across the region: Tipton St John on the River Otter in East Devon, Tregony in West Cornwall and Dorchester on the River Frome.

A number of demonstration plots were set up with different drilling dates, standard and early ripening maize varieties, different cultivation depths and techniques and varying fertiliser and manure levels.

Crops were being harvested either last week or this week, and the yields from each plot are being analysed. Early indications are that the earlier drilled maize (mid-April) will yield higher than the later drilled (mid-May). This will allow farmers a bigger window to establish a following crop or remove compaction before the wetter weather sets in and helping to reduce run off, soil erosion and flooding.

Mel Hall, South West Regional Director of the National Farmers Union, said:Our members often have a very small window of opportunity to harvest their crops, and rely on contractors. Its good to see evidence that drilling these early-ripening varieties of maize have produced profitable yields, allow farmers to get on to their fields before it gets too wet, and could give them more time to tackle any post harvest soil problems.

As farmers across the South West start to bring in their crops, the Environment Agency wants farmers to do what they can now to get rid of any compaction. Soils should be cultivated as soon as possible after harvest, and land sub-soiled when conditions are suitable. Maize stubble should not be left bare in high risk fields. A following or cover crop should be drilled as soon as possible after harvest to help stabilise soils.

Catchment Sensitive Farming, the MGA and the Environment Agency will be running follow-up trials looking at the impact of cultivation and early drilling of crops on the same sites over the winter.

The Environment Agency want farmers to get a better understanding of their land by examining soil structure.

The best thing farmers can do is go out when its wet and dig a hole. Soil that looks saturated can often be bone dry less than 10 cm beneath the surface owing to compaction. Were not expecting farmers to go out and subsoil every field. We just want them to understand which ones are at risk of producing high levels of runoff and tackle those, said Phil Shere for the Environment Agency.

The Environment Agency has produced a ThinkSoils booklet Examining soil structure a practical guide to digging a hole and video clip which explains what farmers should be looking for. The clip can be found on the Environment Agency website at http://www.environment-agency.gov.uk/business/sectors/soils.aspx

• Detail of trials will be available at end of October.

• The Environment Agency has undertaken over 3,000 soil structural surveys across the South West since 2002

• We commissioned Cranfield University to carry out field experiments using a rainfall simulator to measure runoff near Ottery St Mary.

• This work found that maize stubble with loosened soil can absorb high volumes of rain (50mm per hour) with no run-off after an hour of heavy rain.

• In contrast there was 45 per cent runoff from maize stubble with compacted soils, and nearly 90 per cent runoff from grassland with compacted soil.

• Over 90 per cent of maize and arable sites (that follow maize) we assessed [in East Devon] showed high or severe levels of soil structural problems causing run-off

• In 2007 and 2008 we had prolonged periods of wet weather and heavy rain in the summer and autumn. These weather conditions made it difficult for farmers to maintain good soil condition.

• Extreme weather will become more common as a result of climate change. Winter rainfall could increase by 18 per cent by the 2020s and 41 per cent by the 2050s.

• Farmers have been asked to identify actions in their Soil Protection Review which will help ensure soils are in a better state to cope with extreme weather