Feeding a new reseed

Read our information to help you learn about the nutrient requirements of a new reseed. You’ll find information on nitrogen, phosphate, potash and organic manures.

Back to: Managing grassland reseeds

Nitrogen

Nitrogen (N) is a key element in aiding grass establishment. However, during the early stages of plant growth, N requirements are quite low. Applying too much N may encourage regrowth or competition from existing seedlings.

For autumn sowings, high soil mineralisation rates over the growing season can mean that no N is required at establishment.

For spring establishment, apply 60 kg/ha N due to low soil N stores. In the fields that have low to moderate soil nitrogen status, some N could be applied for summer- or autumn- sown swards. This may be followed up with 30–40 kg N/ha four to six weeks after reseeding as plant N requirements increase.

Avoid urea applications to recently limed fields, as the interaction between the compounds can result in higher levels of nitrogen being lost as ammonia gas.

Nitrogen requirements for establishing grass swards

 

Soil nitrogen supply (kg N/ha)

Low

Moderate

High

Spring-sown (April-June)

60

60

60

Summer-or-autumn-sown (July-mid-October)

30-50a

0-30a

0

Grass and clover swards

0

0

0

aNitrogen is important when rapid grass growth is needed, e.g. when seedbed conditions are suboptimal or seed is sown late. Nitrogen should not be applied where it will stimulate weed growth (e.g. in weedy stubbles) or seeding competition (e.g. direct-drilled into an existing sward). Be aware of Nitrate Vulnerable Zones closed periods.

Phosphate and potash

Phosphate and potash are essential for cell development and growth. New leys often require phosphate and potash to stimulate good root development.

Phosphate and potash recommendations for establishing new leys

 

Phosphate or potash index (kg N/ha)

0

1

2

3

4 and higher

Phosphate

120

80

50

30

0

Potash

120

80

60 (2-)

40 (2+)

0

0

Organic manures

Reseeding also provides a good opportunity to incorporate organic manures into soil. This adds organic matter, provides a food source for soil organisms and assists with the development of good soil structure.

More information on fertiliser requirements for grass establishment can be found in the Nutrient Management Guide (RB209).

Useful links

Read more in the Nutrient Management guide (RB209) Section 3 Grass and forage crops

If you would like to order a hard copy of the Nutrient Management Guide (RB209) Section 3 Grass and Forage crops, please contact:

Emailpublications@ahdb.org.uk

Telephone: 0247 799 0069

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