Adding seeds, plants, trees & shrubs to pasture land
Increasing botanical biodiversity on grazing land provides not only a varied diet for horses, but access to a wider range of minerals and vitamins, and could be beneficial for horses that are overweight, or those with laminitis (as access to rich fertilised pastures can exacerbate this); it also resembles what the ancestral horse typically would have grazed, . Wildflower meadows are also of great benefit to the environment as they are amazing carbon stores, (almost as beneficial as woodlands) and support a vast arrange of mammals, birds and insects.
Adding herb seeds to a grazing field is often referred to as a herbal ley and the link below gives useful information about this traditional method:
https://www.agricology.co.uk/resources/herbal-ley-farming-system
Alternatively large areas of pasture that has been agriculturally “improved” can be moved to “unimproved” pasture by spreading green hay (best obtained locally) or adding bulk seed mixes from suppliers such as Emorsgate (https://wildseed.co.uk/articles/2018/02/05/horses-wild-flower-and-herb-rich-meadows-and-buttercups).
When looking to add beneficial seeds it is always best to assess the land and tailor the plants to the areas you wish to plant them in, for example do they prefer moist or damp soil, etc. Additionally adding a range of plants that access different soil horizons, ie, root depth, can be useful, with deep rooted plants being able to access lower level water sources, improve drainage and aid in breaking up soil structure. Options to add the seeds include seeding a strip of land to the edge of a field, or by introducing seeds into small irregular patches, about a metre wide, within the pasture area. To prepare these patches around an inch depth of the top grass should be removed, and the seeds sown on the bare surface. Alternatively the seeds can be sown on any bare patches of ground. This would be more manageable and less costly, and can be increased as required. Adding yellow rattle into these areas would be a very useful addition, being semi-parasitic on grass; particularly when this annual plant dies off it leaves gaps in the grass for wild flowers to establish themselves.
When you have decided on your site, the best time to add seeds to fields are autumn and early/mid spring to reduce competition with grass growth, thus giving them the best chance to survive. Additionally some plants require stratification to germinate, such as yellow rattle, so need to be sown autumn, and if sown at this time It is suggested the area be left for 6 - 8 weeks to protect the seedlings, and then light graze late autumn.
If wanting to add plants to a pasture or track system, established plants or plant plugs that are quite well established, are preferable. The best way to introduce them is to cut the grass short in the area you wish to plant in, and plant them in clumps.
Hedgerows are extremely beneficial in reducing erosion and supporting the ecosystem particularly birds and mammals, and even bats who will fly along hedge lines and feed on insects. Sadly since WWII 160,000 km of hedgerows have been lost, due mainly to intensive farming. Adding hedging and small trees can be done up until the end of March if adding whips, or through the summer if adding potted plants. The plants should be protected for about 2 - 3 years, particularly from rabbits who can damage young tree and shrubs, and a plastic guard, or an environmentally friendly option - burlap, can be wrapped around the bottom of the plant. To protect from horses they should be either fenced off or a wire mesh staked around the plant to allow them to become established.