There is growing interest in the use of diverse forage mixtures (also called herbal or multispecies leys) as a method of enhancing agricultural production while providing environmental benefits.
Why grow diverse forages?
Diverse forages offer multiple advantages to the farmer at a time when farm profits are falling and input prices are rising. Diverse leys include a mix of grasses, legumes and herbs and provide greater on-farm self-sufficiency through the properties outlined below:
Extended grazing season – growing more than one species means that growth habits overlap and swards yield earlier and later than a single-species ley
Nitrogen fixation – including legumes in a herbal ley takes nitrogen from the atmosphere and converts it into plant available nitrogen in the soil
Mineral mining – deep-rooting herbs bring up minerals such as calcium, magnesium and iron; this improves stock health and can have an impact on the health of people consuming animal products
Drought resistance – deep-rooting herbs and grasses tap into moisture deep in the soil, providing grazing during dry conditions
Parasite control – some herbs have anthelmintic properties, this means they reduce gut parasites (link to section)
Soil improvement – deep-rooting leys break up compacted soils and transfer carbon from the atmosphere to the soil, improving soil structure and moisture retention. More diversity in leys increases the diversity of soil biology, improving nutrient cycling (Enhancing soil biology).
Reading University, in partnership with Duchy College and Rothamsted Research, is running the Diverse Forages Project. This aims to research the suitability of diverse forage mixes for agricultural productivity and positive environmental impacts. The project will investigate forage quality, yield, nutritional value, species composition and soil properties from three forage mixes and a ryegrass control grown on a network of farms. This farm network will allow differences in management and local climate to be assessed, in order to understand how best to manage diverse forages.
Guide to Diverse Forage Species
For a detailed guide to forage species and how to grow them, see the Sustainable Forage Protein project. This summarises farm trials run by Aberystwyth and Bangor Universities, Waitrose, Germinal Seeds and Innovate UK.
Establishment and Management
Diverse forage mixtures tend to have small seeds and as a result require a fine seedbed. Seeds can be broadcast or shallow drilled and it is crucial to roll the seedbed thoroughly after planting.
Diverse forages are best managed through rotational or mob grazing, this leaves plenty of leaves and soil cover for fast regrowth. Set-stocking can lead to selective overgrazing, lowering the plant diversity of the sward.
Agri-tech Cornwall is running the “Toolkit of Multi-Species Swards” (TOMS) project through Duchy College and Rothamsted Research North Wyke. This will support the growing interest in multi-species leys by trialling mixes and management technique, with the aim of producing an online toolkit to help farmers make informed decisions.