There’s a widespread understanding of the important role trees play in storing carbon through the process of photosynthesis. However, on a per acre basis, grass can sequester more carbon than trees due to the dense root system and vegetative mass of grass. As such, promoting healthy and abundant grass in horse paddocks enables horse ownership to be part of the solution when it comes to restoring balance in the carbon cycle, rather than part of the problem!
To grow healthy grass, it’s important to focus first on the health of the soil. Healthy soil is alive; rich in organic matter, it has a balanced pH level, and is aerated and oxygenated. Unfortunately, when a horse paddock is continuously grazed without adequate rest and care, the animals inhabiting it will cause soil compaction and erosion. Compacted soil does not effectively absorb or retain water and results in slowed root growth, meaning it is less productive. An unproductive horse paddock not only results in an increased reliance on alternative feed sources – and therefore a more expensive way of feeding your horse – it also means that there is less leaf available on the grass to act as an agent in sequestering carbon!
When seeking to improve soil health, a good starting point is testing the pH level. Alkaline soils with soil pH above 7.5, and acidic soils with soil pH below 5.0, generally stunt plant growth, as plants can’t take up nutrients effectively within these ranges. If your soil is too acidic or too alkaline, avoid using synthetic minerals and fertilisers to rectify the imbalance. This is a short-term solution that will destroy soil microbes and have a detrimental effect on the soil’s health and productivity. Working with nature – rather than against it – will yield better long-term results. An application of lime can help acidic soils, whereas alkaline soils will benefit from the application of mulch and compost.
GRAZING VS REST
With the soil pH in hand, it’s important to next consider graze periods versus rest periods. Adequate periods of rest are critical for the maintenance and improvement of soil health and therefore also the nutrient density and volume of pasture produced. Even in large paddocks with abundant grass, horses tend to choose certain areas where they overgraze, rest, defecate and urinate, dig holes, or walk up and down, resulting in horse-sick pastures.
Spelling a paddock allows the soil to rest and plants to recover and grow. As horses are selective grazers, they tend to seek out certain grasses and eat these right down to their base. Above the ground, we see the impact this has on the leaves of the desired grass species – they are left almost non-existent – meaning that the grass has limited solar panels remaining to start the process of photosynthesis necessary for both regrowth and carbon sequestration!
How long a paddock needs to adequately recover depends on the time of year and whether it is the growing season or non-growing season, the amount of rainfall received during the rest period, and the condition of the soil and grass when the rest period commenced. Plants have three phases of growth: in Phase 1, the plant is drawing on root reserves to regrow, meaning it is not able to photosynthesise. At this stage, green pick is visible; it will be high in sugar, meaning it is not safe for horses to eat, and doing so will stall the plant’s development. In Phase 2, the plant is able to photosynthesise efficiently, meaning it grows rapidly both above and below the ground. In Phase 3, stems and seeds are evident. This is the plant’s reproductive stage, where growth slows and the forage quality starts to decline.