Reseeding in August and get 1 ton DM/ha more in spring grass growth, according to new research

Reseeding in August and get 1 ton DM/ha more in spring grass growth, according to new research

The real benefits of reseeding in August

Reseeding is an essential part of grassland management, but did you know August is the best time to reseed with higher soil temperatures helping new ley establishment, according to new research.

Leys that are reseeded in August allow for greater opportunity for weed control than later sowing when weather conditions and soil conditions decline later into the autumn. The downtime over the winter allows the ley to develop to its full production potential.

Research conducted by DLF Ireland has shown the effect of autumn sowing date on spring growth in the following year. In this research, each of the four sets of plots was ‘autumn’ sown, with two farms sowing their trial plots in August and two in September 2020.

When spring growth rates and yields were calculated for each farm, it was found that by the following April, the two August-sown trials had grown over 1 ton DM/ha more than the trials sown in September (Table 1).

This extra ton of grass is significant at a time when cows are coming into lactation and feed demand is high - Teagasc estimates it could be worth in the region of €250/ha.


3 Grass Essentials

Ensuring a grazing platform has the highest quality grass, and grazing utilisation is essential to maximise grass as a feed source in economic terms.

Three essentials to remember and make reseeding a worthwhile investment.

No. 1. Graze Out – look for utilisation and low residuals, not just volume. A variety that delivers 15T is not much use on a farm if the cow won’t eat it!

No. 2. Yield - If the variety grazes out, you want it to produce as much as possible

No. 3. Quality - with your utilisable yield determined, we want that to be of the highest quality possible

When sowing, choose a grass mixture with an excellent combination of high yields, quality, and persistence.

Research shows that each extra tonne of grass dry matter utilised is worth €181 and €105/ha per year to dairy and dry stock farmers, respectively.

Sowing a grass mixture that produces high yields of quality forage throughout the season is key to maximising grass utilisation on farms.


Making the most of your reseed

Specialist Nutrition can help you choose the grass mixture most suitable for your on-farm forage needs but first, let’s look at some top tips for reseeding:

Reseeding Tips

- Take a soil sample at 10cm (4 inches) to analyse pH, P and K indices

- Spray off the old sward and ensure there is enough new growth for the chemical to be taken up

- Begin cultivations 7 – 10 days after spraying off & ensure low level of thrash before cultivating particularly where using minimum cultivation techniques

- Apply seedbed fertiliser as required. Apply lime to achieve 6.5 pH at a maximum of 6t/ha (2.5ton/acre). Split dress if more is required. Do not use high nitrogen fertilisers on a grass reseed

- Drill or broadcast the seed onto the rolled seedbed. Ring roll or light harrow to ensure maximum contact between seed and soil.

- Weed control in the new ley is usually necessary to ensure good establishment around six weeks after sowing in normal conditions; herbicide choice will depend on the presence of clover or not

- Graze periodically from 8-12cm down to 3-6cm. This will help achieve a dense, tillered sward. The removal of grass allows light to reach and stimulate grass tiller buds and clover growing points.

- If significant weed problems are expected, you may consider establishing the ley without clover and introducing it once an herbicide has been applied to the sward

Our team will collaborate with you, recommend the best mixture for your farm, and offer advice on establishment, grassland management, grazing utilisation, and silage conservation to deliver quality swards.

Specialist Nutrition | Moist Feed and Forage Specialists

Call 051 833071