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Establishing a grass ley

When to sow
There are two main opportunities for sowing: spring and autumn.  Traditionally leys were commonly established in the spring under a cover crop such as barley.  Now many farmers prefer to sow in the autumn following a cereal crop.  Of course, choice of sowing time is often dictated by livestock requirements and other cropping on the farm.

Moisture availability is an important consideration when establishing seed and spring sowing can run into drought issues, whereas rainfall is usually more reliable in the autumn.  However, if sowing legumes, such as clover, spring sowing may be better as these plants grow better in warmer temperatures.

If sowing in the autumn, some people sow grass only and introduce clovers the following spring after grazing or cutting the grass.  This allows for the use of sprays to control annual weeds.

Good preparation of the seed bed before sowing is vital to achieve a fine tilth.  Grass and clover seeds are small and so need to be in close contact with the soil before they can germinate.

A cloddy (or lumpy) seed bed will hamper germination, so it is best to harrow or disc the soil to break it up.

Once this has been done, it is important to roll the seed bed before sowing any seed.  Rolling will consolidate the soil and make the seed bed firmer.

Sowing method
Grass and clover seeds can be drilled or broadcast, but it is vital that the seed does not go in more than 1cm deep.  

Mixes with a lot of clover in them are better broadcast as the clover seed needs to be on, or very near, the surface.  However, sometimes drilling is better, for example when the soil is stony.  If drilling, the width between the drills should be narrow (not more than 10cm) to ensure the correct density in the ley.

It is best to use a specialist grass seed drill (such as the Aitchison) as corn drills will put the seed in too deep and the rows too wide apart (which encourages weeds to establish).

We recommend rolling three times: once before sowing or drilling then in both directions afterwards.  A ring or Cambridge roller is best, but a flat roller is good to finish.

Germination can be expected within two to three weeks. 

Managing a newly sown ley 
Management is dependent on the speed of grass growth and height of the sward. This will vary according to the soil temperature (minimum 5° for grass growth and 8° for legumes) and an adequate supply of moisture.

Light grazing can commence when the grass is around 8-10cm high, usually after around 6-10 weeks after sowing.  A light grazing is best to start with and this will help thicken up the sward by encouraging tillering.  

Alternatively, the field can be shut up and allowed to reach the flower emergence stage when a cut can be taken of silage or hay.  In the first season, on longer term leys, it is preferable to graze only, waiting until the second year for a cut.

According to Sir George Stapledon, the famous grassland pioneer, the sheep is the best animal for establishing a good ley. This is because sheep firm up the soil with their small feet.  They also nibble tightly, so encouraging tillering, and graze out weeds.

If using sheep, do not allow them to graze too tightly at first or they may pull up young grasses.  Cattle will certainly do this, so are not suitable to graze a young ley.  

One way of establish a grass ley is to undersow it to a cereal crop.  This means that a ley is already well established immediately after harvest.  

If undersowing, the seed rate for the cereal crop should be lowered to allow space for the young grass seedlings to develop.  Barley is ideal and should be sown at around 50kg/ac.  Wheat is less suitable unless it is spring wheat, a more open crop.  Winter wheat is too dense and not recommended for undersowing.

 If drilling spring barley in February, then it is best to wait and drill the grass should in late March in most districts.  If drilling the barley in late March, then the grass can be sown (separately) the same day. 

Date Posted: 29th March 2017