Environment Agency
A wetter than usual summer means there is a risk maize crops will not mature until late autumn in some areas, leading to a late harvest when soils are wet due to seasonal (autumnal) rainfall.
Tractors and loaded trailers can cause soil compaction when harvesting in these conditions, potentially leading to an increase in run off which could result in local flooding and pollution of nearby watercourses.
The Environment Agency is calling on farmers to loosen the soil after harvest if compaction has occurred. Attention should be paid to compacted headlands and wheel ruts acting as pathways for runoff.
Devon and Cornwall project manager James Wimpress said: Harvesting later than 1 October can be risky as soils may be soft following rainfall and prone to compaction. This can lead to increased runoff over the winter.
We recognise that there has been great improvement with managing maize in recent years, including cover cropping and managing compaction, but we would encourage farmers to be vigilant with late harvests, particularly if the weather is wet.
The Environment Agency is also recommending Devon and Cornwall farmers consider growing other types of crops instead of maize in future due to the likelihood of climate change leading to more extreme weather.
James added: In some areas it may be better not to grow maize in the first place because the soil and location are at very high risk of runoff during bad weather, causing localised flooding and pollution.
These areas include steep slopes on sandy soils that are vulnerable to soil loss and erosion during heavy rainfall, and wet clay soils with poor drainage where it is difficult to harvest maize without causing serious compaction and damage to the soil.
High-risk crops, grown in high-risk locations, increase the likelihood of pollution incidents from soil erosion and run-off. The Environment Agency will take enforcement action if it finds that reasonable precautions to prevent pollution, which include the choice of crop and associated agricultural practice, have not been taken.
Further information
The Farming Rules for Water, introduced in April 2018 as part of a wider package, state, the land manager must ensure that reasonable precautions are taken to prevent pollution resulting from soil loss caused by land management and cultivation practices. For further background read the 2017