Repairing the damage from 2012

Published 15 February 13

Repairing the damage from 2012

Soil and grassland management specialist Chris Duller talks about the damage caused by the incredibly wet season in 2012 and what to do about it.

In many places across the UK 2012 was one of the wettest on record and there are three key impacts of all that rain on grassland.

  • Damage to soil structure - surface poaching, deep compaction and cultivation damage.
  • Loss of nutrients - soluble nutrients lost (nitrates, potash and calcium).
  • Damage of sward - ryegrass content, weed ingress, sward density.

Most places had at least 200mm more rain than an average year, and add to this reduced evapotranspiration due to lack of sunshine and colder temperatures, and soil really had to deal with a lot of moisture in 2012.

All this extra water moving thorough or over the soil increased leaching (loss of N, K and Ca), increased denitrification and surface run off (phosphate loss). It meant poorer nutrient cycling and heavy mature silage crops.

Soil compaction means open swards, less ryegrass and more opportunity for weeds. It means less worm activity, nutrient cycling and less root depth. This means poor drainage which can lead to lower soil temperatures. All this adds up to a poorer response to nutrients and lower yields and lower quality.

Grass utilisation was down in 2012 and some farmers had to house for periods over the summer and/or bring cattle in early, and most had to feed more. In fact many found it almost impossible to get on the land to fertilise, effecting growth rates further.

You need to think about repairing the damage from 2012 season

Decide what the major soil issues of 2012 were for you. Are there poor areas around gateways and troughs? Is there poaching damage, and if so how severe? Has there been machinery and cultivation damage?

Do a field by field swot analysis to find out what your problems are, what is the likely cause and what actions are needed. Will the field recover on its own or will it get worse if you leave it? It's important to test the soil to see where you are nutrients wise and it is just as important to know your soil texture. Soil texture has a direct impact on how you manage your soils and on the problems you are likely to face. 

Help soils recover in 2012

It might be an uncomfortable truth but this spring, in order to avoid having problems for months to come, you need to prioritise helping your soil recover rather than hitting your grazing targets.  

Try to avoid grazing damaged areas in wet weather. It's better to graze these areas on dry days even if that means going into a paddock at below what you might think is adequate cover. Take the opportunity of dry weather to get them grazed off. Think about coming out of these paddocks at higher covers than previously as that extra grass will help protect the sward; you can always pre mow next time round to correct a poor residual.

Keep stocking rates low by grazing lower covers and allocating more grass, thus avoiding further damage.

If conditions stay wet lock damaged areas out for silage rather than risk grazing again and damaging soils further.   Equally on silage ground - think about tackling your most damaged fields when conditions are best - maybe harvesting one field early as bales in dry conditions. Whatever you do to these areas, do when conditions are dry.

You need to treat damaged areas with kid gloves and a lot of tender loving care.

Further actions.

  • Avoid slurry/dirty water in trouble areas to allow worm levels to recover.
  • Aerate if conditions allow and the depth of compaction is suitable.
  • Encourage tillering by avoiding high covers, premowing and don't shut out for silage.
  • Soil test to make sure ph and P and K are spot on.
  • Grass harrow to remove moss and weeds.
  • Reseed early if necessary.

 Monitor and gauge recover and importantly keep walking the fields.