Knowing whether your soil type is predominately clay, sand or silt is helpful for ensuring you have the right grass species for your paddock to help keep your horses in good health.
We can’t change what is given in our soils but we need to know what the proportions are to be able to manage the grass effectively.
Soils are usually a mixture of all three in varying proportions and are classified accordingly. Soil classification is analysed using particle size and the constituent parts to determine the soil type.
Types of soil
Sand
This is effectively dead and inert. It is only good for creating free draining soil, but has little if any nutrient retention capability. Therefore, sandy soil is highly prone to droughting off in the summer months, or eroding in excess wind and rain. Grass species selection in these soils is vital for sward survival.
Silt
These soils tend to ‘run together’, excluding air and drowning the essential soil borne bacteria, which impede grass productivity. Developing a strategy to maintain the ideal balance between air and water (25 per cent of each) is a challenge. Thankfully, these soils are predominately old flood-plains and, therefore, have a highly productive level of organic matter of well over five per cent to sustain productivity once the sward is persuaded to work.
Clay
Soils that are predominantly clay are a double-edged sword! Their miniscule particle size and negative charge mean that they have the propensity to retain high levels of essential nutrients, for the grass to utilise, by holding the positively charged Cations in the soil and generate and sustain fantastic grass.
The problem is that they are highly prone to either waterlogging in the winter, or droughting off in the summer – turning to dust. It is difficult to maintain the air / water balance in these soils (25 per cent of each) for productivity without timely attention to detail.
However, when these soils are carefully managed over several years they will maintain themselves and sustain many horses.
Loams
These are mixtures of clay, sand and silt that avoid the extremes of each type. For example, Sandy Clay Loam = mostly sand with some silt and clay. Consequently, these soil types are generally easier to manage to maintain productivity.
Soil analysis and action to take
At Lordington Park Agronomy, we take your soil samples for analysis. Armed with the knowledge of your soil type, the pH and the level of organic matter, the next step is implementing appropriate actions to sustain productivity, such as selecting the right grass species to optimise the requirements of your horse.
The important point to consider is ‘how does a root absorb nutrients?’ If a plant can’t access nutrients from the soil, then the sward won’t survive. Essentially, a root generates a slimy outer coating that allows it to move easily through the soil, expanding its surface area and therefore potential for absorbing nutrients. This slime (exudate) is specifically designed to be full of amino acids and sugars that attract the soil-borne mycorrhizal fungi to a free feast! In exchange, they free up the nutrients that are normally held in the soil colloid enabling the root-hairs to absorb them by osmosis.
Ensure that your soil has good levels of available Phosphate (P) and Magnesium (Mg) as both are essential for root development and production. As the surface area of the root increases, nutrients supply for the grass increases.
The right grass species
Many of the native grass species confer significant benefits into any sward and proportionately increase nutritious food supply, and the long-term survival of any sward.
Sheep’s Fescue, Festuca ovina
A species that was born to survive in any adverse environment!
Able to adapt to poor soils by generating mycorrhizal fungi, which increase the absorption of water and nutrients and are potential determinants of plant community structure in the sward.
Only shallow rooted (25-35mm) but the mycorrhiza assists other plants in the sward to flourish, enabling long-term productivity in challenging conditions.
Creeping Red Fescue, Festuca rubra
The under-ground rhizomes (under-ground stems) store energy so that this species can recover from drought quickly, Crucially the rhizomes help stabilise the soil for the benefit of the other grass species in the sward allowing them to readily access nutrients.
- Provides excellent sward stability due to the development of widespread underground rhizomes
- Grows well on all soil types
- Tolerant of drought conditions once established
- Pliable leaves that withstand traffic well
- Low nutritional content, but ideal for horse’s digestion.
Cocksfoot, Dactylis glomerata
The corner-stone of productivity in the UK for centuries. Innate ability to withstand nearly any of our Great British weather any weather. The huge root mass stabilises the soil, and allows the soil environment to flourish – perfect to open clay soil out, and stabilise sands once established.
- Winter hardy, extremely drought tolerant grass
- Huge root mass that allows the soil and sward to function more efficiently
- Retains moisture in the root mass (120mm depth) for another species to utilise
- Excellent feed value similar to perennial rye grass
Meadow Fescue, Festuca pratensis
If you are unlucky enough to have a soil with a low pH (below a pH of 6) then this species must be included in the sward.
- A bunch-type growth habit that is excellent for generating a dense bottom in any sward environment
- Generates weak rhizomes that help increase propagation
- Drought tolerant, and thrives in acidic soils
- Reasonable feed value even in a drought prone environment