The good dry weather conditions over the past week has helped fields to naturally repair some of the damage caused by a wet spring. However, some wet spots in fields remain due to compaction issues. In addition, there are many fields around the country that still require reseeding or over sowing with grass seed to fill in a damaged and open sward.
Examine the costs
Compaction damage can usually be solved easily, with a full plough and reseed. However, in most cases, this can cost up to €250 to €280/acre. After the financial tolls of a difficult autumn and spring, many livestock farmers are not in a position to fork out large amounts of money for reseeding, and where stocking rates are low, the return on the investment may be questionable. For that reason, farmers should look at cheaper alternatives.
Repair compaction damage
Compaction caused by cattle grazing fields usually occurs in the top 4in to 6in of the soil profile. The dry spell will naturally have repaired this damage by allowing the clay to dry out and crack, causing fissures in the compaction layer.
However, there are many fields that still have wet spots or areas which may need mechanical assistance in order to rectify the compaction. This can be done by using any type of subsoiler through the soil at depths of 6in to 10in.
Consider over-sowing
Where the existing sward is damaged and open, but contains a high percentage of perennial rye grasses, then over-sowing may be a cheap alternative to reseeding.
Stitching-in
One of the disadvantages of a full plough and reseed is that, more often than not, you end up ploughing down fertile soil and ploughing up more-alkaline less-fertile soil. Stitching-in offers some substantial advantages over full reseeding. Only the very surface of the soil is disturbed, so the most-fertile soil should remain on the surface.
In addition, because the soil is not disturbed, it means that livestock can get back grazing this ground more quickly than a conventional plough and reseed. This may be a particular benefit where there is only heavy stock, such as cows or forward store cattle, on the farm.
Plough and reseed
As said previously, a full plough and reseed is generally the most expensive method of reseeding. However, it is preferred in areas of heavy ground in order to improve soil drainage by alleviating compaction damage.
The speed of regrowth on a full reseed has been shown by Teagasc to be the fastest. However, in the second season, there is no obvious difference between a stitched-in sward versus a full plough and reseed sward. Light stock will be required to graze off the initial regrowth until the clay settles after seeding.
Management of a new reseed
The management of a new reseed is essential.