Reseeding in 2022: what you need to know

Prior to the outbreak of war in Ukraine, all the talk was of mitigating rising fertiliser costs. Since the war started, the discussion has changed away from price and to supply. Will Irish farmers be able to access fertiliser, grain, diesel and a raft of other inputs? They say money can’t buy health or happiness. Maybe more items will be added to this list before 2022 is out.

In relation to grass seed, there should be no real issues with seed supply in Ireland. The majority of our grass seed is produced in England, Holland and Denmark.

Demand for seed is unlikely to be any higher than normal. In fact, it may very well be back on other years.

The opposite is likely to be the case with clover seed. Heralded as the saviour of Irish agriculture due to its ability to fix atmospheric nitrogen to the soil, there is likely to be increased demand for clover seed as farmers try to mitigate high prices and short supply of chemical nitrogen.

In a worst-case scenario, there could be a fodder deficit on some farms

The question as to whether this is a good year to reseed needs to be considered.

The background to this question is that silage stocks are likely to be lower than normal heading into next winter and concentrate feeds are likely to be very expensive and in short supply also.

In a worst-case scenario, there could be a fodder deficit on some farms, depending on how readily available inputs are and how affordable they are.

Overall production

In terms of overall production in the year they are reseeded, it’s accepted that fields reseeded in spring have similar or greater annual production as they had prior to reseeding.

In other words, the much higher performance after reseeding compensates for the loss of performance during reseeding and the poor performance prior to reseeding.

However, taking land out of production for reseeding will mean there is less land available for winter feed production and grazing during the eight to 10 weeks when the field is out of production. This period usually correlates to the time that grass growth is at its highest.

I think there are two ways to look at it; if the farm has good swards and fertile soils and has a high demand for grass and silage then reseeding could be skipped this year in order to focus on having as much silage as possible.

Sourcing and paying for fertiliser to improve soil fertility is a challenge this year, but it’s much better to get this right first before reseeding

If, on the other hand, sward quality is poor and paddocks are under-performing it will probably pay to carry out reseeding this year. The caveat here is that soil fertility and any drainage issues should be corrected before deciding to reseed a field.

If these underlying issues are not addressed, then reseeding will be a waste of time as the new ryegrass won’t last and will instead be replaced by weed grasses within a few years.

Sourcing and paying for fertiliser to improve soil fertility is a challenge this year, but it’s much better to get this right first before reseeding. Cattle slurry, pig slurry and poultry manure are valuable sources of P and K, where available.

1 The first step when reseeding a field is to spray off the old vegetation with glyphosate. Allow sufficient time for the spray to translocate to the roots of dock plants, if present. The best thing to do with sprayed off fields is to cut them for silage after seven to 10 days.

2 Decide on the cultivation method: ploughing or min-till. There is less soil disturbance and less nitrogen leached with min-till. There is usually no difference in sward performance between the methods once carried out correctly.

3 Reseeding is an ideal opportunity to spread lime on fields that are low in pH. If using min-till methods, lime must be spread before sowing as it helps to neutralise the acidity caused by decaying thrash.

4 Choose grass varieties with a high pasture profit index (PPI) value (see pages 46 and 47). Most farmers purchase their grass seed pre-mixed from a local merchant.

There is usually little difference in the price of high PPI value grass seed and that of lower-value seed so always choose a good mix based on the purpose of the field such as intensive grazing or silage.

I can see of no circumstances where clover should not be included in a seed mix.

5 Roll well after sowing. This is a critical step and an area that many farmers fall down in. I would hazard a guess that many rollers being used in Ireland are not heavy enough, probably because they are leaking water. It’s best to roll twice in both directions.

6 Monitor young seedlings for signs of pests such as leatherjackets, frit fly and slugs.

7 Use a clover-safe spray to kill weeds when dock seedlings are about the size of a €2 or 50p coin.

Interest is increasing in multispecies swards and with a new scheme on its way from the Department of Agriculture, Food and the Marine to support the planting of these swards area is likely to increase.

The scheme is likely to see a requirement for these swards to include perennial ryegrass, timothy, both red and white clover and plantain and chicory. This is in comparison to the mixed species ley option under the Results-Based Environment-Agri Pilot (REAP) project. The highest scores under that programme were achieved where seven legumes or herbs were found in the mix.

The high clover content of these swards can allow for significant reductions in artificial nitrogen fertiliser use, while different root types and depths can help to improve soil structure.

It is important to note that if you are struggling to grow clover on your farm, then multispecies swards may also prove difficult

Research into these swards is still in its early stages, but there are a few things that farmers should keep in mind if considering planting. Soil pH of 6.5 is needed and P and K ideally at index 3 or 4.

Preferably plant on land with low levels of weed infestation.

It is important to note that if you are struggling to grow clover on your farm, then multispecies swards may also prove difficult and getting the basics right before establishment is important.

A survey carried out by the Irish Farmers Journal and University College Dublin showed that 46% of those establishing multispecies swards ploughed, while 43% used minimum tillage and 9% stitched in. A total of 82% were happy with the establishment of these swards, while 39% of respondents stated that weed control posed the biggest challenge for those surveyed. Many of those surveyed had planted in 2020 and 2021 and were still examining the success of these swards.