Managing herbal leys

See our information on choosing species for herbal leys and how to manage for grazing and silage.

Choosing species that will suit your farm’s soil types and the planned grazing or silaging regimes is a great starting point. Alternatively, buy a seed mix and see what persists on your farm. Choice of species can then be perfected over time to those species suited to your system.

There are many species that can be used on farm, and these can be classified according to their preferred soil type. Remember to choose species that will suit soil types on your farm:

• Lighter soils suit deep-rooted species
• A few species are relatively easy to grow and grow on most soil types
• Heavier soils suit species that prefer moisture and fertility

Please note, this table is a rough guide. If in doubt, consult an agronomist or seed merchant for further advice.

• Do not put sainfoin or lucerne in acidic soils – use alsike clover and trefoil to add extra diversity to acid soils
• Rotationally graze on typically a 28–38 day rotation
• Target the use of anthelmintics – this may require a new approach
• Do not use chicory in a cutting mix
• Buy seed inoculated with rhizobia, as the specific rhizobia may not be present in soil – this can improve performance of the species

Studies have shown that yields of herbal leys can be comparable to ryegrass leys, depending on soil type and year conditions. However, there are differences in production over the growing season. Typically, perennial ryegrass reaches peak production earlier in the season, whereas herbal leys will reach peak production later in the season.

Over time, swards are likely to become grass-dominant. This can be managed by including a number of grass and legume species in the mix so that there is still a variety of species over time. Management tips for grazing:

• Livestock may take a few days to adapt to the bitter taste
• Graze cleanly to encourage persistence and diversity of species
• Control weeds by frequent cutting
• Cows are unlikely to eat chicory stems – they may require topping
• Adding nitrogen to a legume sward will suppress the legume and encourage grass dominance
• Graze off by October and then leave over winter

Sward meters can be used to estimate yield but need to be calibrated specifically to account for sward maturity and species composition. DM estimation normally measures between 9 and 15% DM but is less accurate due to the proportion of leaf in herbal leys. Using a quadrat to cut and weigh can be more accurate.

Herbal leys can be successfully ensiled when using the correct practices. Herbal leys differ from grass swards by having lower sugar, high protein, and a different mineral profile, which influences fermentation. Tips for successful silage:

• Cutting time is key – cut before the plants become too stemmy, when the plants are highly digestible
• Additives are recommended for legume swards to improve fermentation
• Dry matter – target 28–32% DM for clamp silage and 35–45% for bales
• Getting an accurate nutritional analysis of herbal leys is challenging – opt for neutral detergent fibre (NDF), crude protein and fibre fractions through wet chemistry instead
• Herbal leys can be used for silage in the first year, but they can have a high nutrient content which makes fermentation challenging