Waterlogged fields will need special attention to salvage yields this season following one of the wettest starts to the year, say experts.
The wettest January for almost 120 years means root stress could lead to failed crops. High rainfall during the last two months following a huge dump of water from Storm Goretti has left ground saturated and crops struggling from root stress.
Shane Brewer, from soil testing specialists Eurofins Agro UK, suggests that waterlogged cereals and other crops trapped under flood water for more than 15 days will almost certainly be lost.
Soil testing
Longer-term damage to soil health can only be ascertained by testing regularly once the flood waters have subsided, says Mr Brewer. Soil testing will identify the levels of bacteria, fungi and protozoa in the soil, he adds.
The roots of flooded plants stop taking up nutrients and methane is produced in the soil instead of carbon dioxide. Ethylene also builds up in the plant roots which will subsequently affect the way any new seeds germinate.
“Should a farm choose to abandon a winter crop and sow a spring crop, a soil test will be vital to understanding how that crop will need to be treated,” adds Mr Brewer.
Microbial populations decline when soils are flooded, and aerobic bacteria are replaced with anaerobic bacteria which produce gases like methane and nitrous oxide. The reduction in oxygen in the soil will also mean lower earthworm numbers.
Crop growth
“Topsoil contains the phosphorus, nitrogen and carbon that will help a new crop grow and, without it, farmers will need to understand what levels of inputs are needed to help soil recover.”
Soil compaction is a growing concern, because, when hit by heavy rain, compacted soil lacks the air space to absorb water. This sees rain run off the land, taking topsoil and nutrients with it.
“Deeper soil can absorb more rain, but in the UK we have large areas that have suffered years of compaction and lack the depth needed to cope with the sort of rain we have experienced this winter. To get the most out of compacted soil, testing will be required to help cultivation decisions such as whether to plough, if minimum tillage options are not deemed suitable.”