Renovating horse pastures

When does a pasture deteriorate?

Why does a pasture deteriorate?

Under-grazing, late grazing or mowing for forage, over-grazing, trampling, lack of fertiliser, lack of pasture maintenance and subsequent weed development, can all be causes of pasture deterioration.

How to take action prior to deterioration?

Good pasture management is essential through several practices :

• Rotational grazing with a high grazing load when grass growth is at its utmost in Spring
• Early grazing to restricrt the development of certain weeds and rough areas
• Mowing, or other grazing animals (cattle) to limit the appearance of roughs
• Alternating grazing and mowing
• Rest the pasture in winter, and restrict grazing in wet weather conditions.
• Fertilising taking into account exports due to mowing.
• Adopt pasture maintenance techniques in Spring and Autumn.

The horse also leaves areas called roughs, where droppings accumulate. The vegetation in these areas hardens over time, and becomes less and less palatable. Also, when the grass cover is kept high, it overshadows young shoots, and slows down their growth. These areas then become favourable to the growth of unpalatable nitrophilous grass (which thrives on nitrogen), and where legumes disappear.

On areas used to distribute hay, or paths, the appearance of bare patches caused by trampling also increase deterioration of the plant cover.

Over-seeding, or total renovation with ploughing followed by re-seeding are costly processes which require carrying out a pasture plant identification, so as to choose the most appropriate means of renovation with regard to the situation. A diagnosis of the soil to determine whether ploughing is feasible (appearnce of stones, unfertile soil) should also be considered.

Results of a pasture plant identification

Seeding, and overseeding

We use the term seeding when the purpose is to replant a plant cover on a totally bare soil. On the other hand overseeding is used with a purpose of refurbishing bare areas in a pasture, without destroying the plant cover already present.

Conditions in order to succeed

• The time of year : Seeding at the end of summer or the beginning of autumn is easier than seeding in the spring. Weed competition is lower during the winter.
• Identifiable bare areas :
  • + 10% of bare soil for overseeding
  • + 30% of undesirable plants
  • < 30% of good grass species and leguminous grasses (for seeding see the chart below)
• The remaining grass cover should be short
• The soil should neither be too wet, nor too dry.

Equipment

For seeding, following destruction of the existing plant cover (either chemically or mechanically)

• With a rotovator (no more than 8cm deep) or a tool with teeth like a vibrashank cultivator or a harrow to obtain a fine grained soil on the surface.
• A level packed down soil  should be obtained by using a roller before seeding
• Just after seeding, the seeds should be surface covered (<3cm depth).

For overseeding and seeding :

• Broadcast seeding with a disc, air or packer seeder.
• Favour good contact between seed and soil, by rolling  (seeding), or trampling by the animals (overseeding)

Density of seeding

The dose of seeds is determined by the number of seeds per gram. This number is variable depending on the type of grass used. The aim is to obtain 500 plants per square meter. The recommended quantity of seed for a bare surface varies between 10 to 25 kg/ ha for the main types of grass and pasture legumes (Gnis reference). Do not exceed 25 to 30kg/ha in the case of a mix. 

⇒ Refer to the supplier for information

To maintain a pasture by overseeding with grass species, we recommend an almost complete dose (20kg/ha of grass species + 3kg/ha of white clover or 6 kg/ha of red clover).

There are no particular species of grass or legume to favour for horses pastures or forage production areas compared to other herbivores. The aim is to maintain a permanently turf like surface and a productive plant cover based on grass species. The presence of legumes such as clover is beneficial because of its protein content, but should not exceed 20 % of the plant cover.

The choice of grass species therefore depends more on soil and climatic conditions, and on the use, be it for grazing and /or fodder production.

To obtain a satisfactory result through overseeding, it is best to choose species which will establish quickly, and species which are said to be aggressive like tetraploid rye-grass (less resistant to trampling), or a hybrid rye-grass, and white clover mix.

For pasture use for horses, it is best to choose turf type species, resistant to trampling (diploid species) and late heading species.

by F. Hubert, 1998

Dominant species: These are the species which will ensure the major part of the production of grass or hay.

Accompanying species: These species do not necessarily produce much yield, but they offer a good ground cover, which prevents the development of weeds.