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Soil erosion control in maize - SP0404

Soil erosion is a major problem in many maize growing areas of the UK and the problems are likely to worsen further as the area of maize grown continues to increase with the introduction of further cold-tolerant varieties. There are problems of rill (gully) and sheet soil erosion with sometimes spectacular incidents and frequent serious but insidious problems associated with soil particulate run-off. There are also problems relating to nitrates and to some extent herbicides, but more especially phosphates, being washed-out of maize crops into water courses causing long-term pollution. However, growing maize in a bi-cropping system with a perennial or at least semi-permanent understorey offers potentially enormous advantages in reducing these hazards.
Work is needed to demonstrate the advantages of growing maize with an appropriate understorey in the UK. In parts of the USA crown vetch (Coronilla varia) is grown routinely as an understorey in maize specifically to prevent soil erosion (Hartwig, 1983). Work on the Continent, especially in Germany and Switzerland (e.g. Ammon & Bohren, 1996 and Bigler et al.,1995) has shown that various understoreys can be grown within the maize crop, the maize crop yield is sustained and there are major benefits in terms of soil erosion reduction. As well as the virtual elimination of soil particulate erosion probably, although not tested, there is a major reduction in phosphate leaching (which is usually associated with soil particulate run-off). Other advantages observed are the reduction of herbicide usage and increases in the biodiversity of beneficial invertebrates.
Clearly there is considerable scope in the UK to grow understoreys within maize in order to control soil erosion, as has been done on the Continent, and to overcome the other problems referred to above. The work will establish the value of understoreys, winter cover crops and the strategy of growing maize at closer spacings to prevent both soil erosion and phosphate losses into water courses. The work will be done with the full support of the Maize Growers Association.
Year 1
1. Establish experiment and determine the level of soil particulate run-off and phosphate loss from plots of maize that are:
at North Wyke
(i) grown conventionally
(ii) grown with a clover understorey
(iii) grown with a ryegrass understorey
(iv) where a winter cover crop is used
at Long Ashton
(v) grown with different row spacings/cultivations/slope

Year 2
2. Repeat measurements of soil particulate run-off and phosphate loss from (i) – (v) at the North Wyke and Long Ashton sites.

Year 3
3. Establish experiments at other site(s) and develop further anti-erosion cultural practices.

Project Documents
• Final Report : Soil erosion control in maize   (211k)
Time-Scale and Cost
From: 1998

To: 2001

Cost: £155,907
Contractor / Funded Organisations
Institute of Grassland and Environment Research (IGER)
Agricultural Land              
Environmental Protection              
Fields of Study
Soil Protection