Groundcover on horse properties includes living plants (pasture, natural vegetation) or dry plant residues,
stones or gravel etc., or even manure. It is important that there is adequate groundcover on properties to prevent
the risk of soil erosion by water or wind and to reduce dust which can lead to problems with horses' health.
Soil erosion by water (i.e. rain washing soil from the paddock) can result in pollution of water in creeks and dams and
cause dams to fill up with silt. Soil erosion causes loss of the most fertile part of the soil, which reduces pasture growth.
Other effects of soil erosion are the build-up of soil on fences and roads, and dust storms.
Bare soil in paddocks is also a problem because it increases the risk of horses getting sand colic.
Dust also increases the risk of horses getting respiratory tract infections.
On horse properties, soil erosion is most often a problem in places where horses congregate and bare spots develop as
a result, such as near gateways, along fencelines, feeding areas etc. Steep slopes and watercourses are more susceptible to erosion.
There is a higher risk of soil erosion when pastures are resown if the soil is cultivated or there is no plant cover.
In South Australia, property owners have a responsibility to take reasonable steps to prevent land degradation (such as soil erosion)
according to the Natural Resources Management Act 2004.
Suggested steps are:
Step 1
Measure the groundcover level in your grazing paddocks at least twice a year, e.g. at the end of winter and the end of summer.
Percentage groundcover means the proportion of the soil surface that is covered by plant material or similar.
One way to measure percentage groundcover is the 'wire' method (see box at right).
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| Illustrations of different degrees of ground cover - 50% (above) and 70% (below). |
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If the groundcover levels on grazing areas are less than adequate, this may be due to one or more reasons, such as low soil fertility or unsuitable soil
pH, lack of desirable plants in pastures or aspects of pasture management such as grazing management.
Step 2
Assess soil fertility and soil pH levels.
Desirable pasture plants need reasonably good soil fertility levels as well as a soil pH that is not strongly acidic.
- Undertake regular (e.g. every few years) soil tests for fertility and pH. Advice and assistance for soil testing is available from departments
of agriculture, rural merchandise outlets, rural consultants and fertiliser companies (see links).
- Apply fertiliser and/or lime. based on those soil test results Fertiliser is usually applied in April-May, and lime can be applied at any time of
the year that you have access to paddocks. Pastures usually need 'maintenance' dressings of fertiliser each season to maintain good condition.
Also, consider surfacing roads, tracks, yards and other high horse-traffic areas to prevent erosion, dust and mud and manage stormwater runoff.
Step 3
Ensure that pastures have a good composition of desirable pasture species.
Pastures that have a lot of weeds and annual plants quickly become bare over summer, whereas perennial plants give good groundcover through summer.
- Identify the amount of desirable pasture plants and weeds present in your pastures. Assistance for pasture species identification and
pasture management is available from rural consultants.
- If pastures are mainly weeds and/or annual species, consider re-seeding pastures with recommended pasture seed mixes. In the Adelaide Hills, it is
recommended to resow pastures with 20 perennial pasture grass plants per square metre plus 60 sub-clover plants per square metre.
- Control weeds where necessary.
Step 4
Make sure that pastures are grazed evenly and not overgrazed.
- Consider rotational grazing of pastures. This means putting horses in a paddock only for a certain period, then moving them to another paddock to spell the pasture. For best results,
grazing should start when pastures grow to 10-15 cm height, then pastures should be spelled when the pasture has been grazed down to 3-5 cm height.
Grazing pastures down below 3 cm height weakens perennial grass plants, and groundcover levels may get too low. Rotational grazing is easier if there are
many smaller paddocks on the property rather than a few large paddocks.
- Manage excess manure in grazing paddocks (see Management of Manure) so horses graze pastures evenly and the pasture doesn't become rank in patches.
- Rotate the position of feeding areas and troughs so they are always on well covered ground.
- Hand feed, stable, or consider agistment at times before groundcover levels in paddocks get too low.
- Prevent fenceline 'tracking' (see Fence Line Tracking) by using double fencing or by keeping more than one horse in grazing paddocks.
- Pay special attention to areas where horses congregate (gateways, along fence lines, feeding areas) as they are more likely to bare the soil there.
- Be especially vigilant of ground cover levels in fragile areas (steep slopes, water courses, wet soil areas) as these can be damaged more easily by horses.
Remove horses immediately when there are signs of damage to the pasture or before ground cover levels get low.
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Best Practice
All grazing areas have ground cover of at least 70% (for soil susceptible to water erosion) or 50%
(for soil susceptible to wind erosion*) at least 3cm high throughout the year.
It is important that there is adequate groundcover ... to prevent the risk of soil erosion.
Wire method of measuring groundcover
- Take a straight piece of fencing wire that reaches approximately to your shoullder height.
- Bend one end of the wire to form a handle.
- Choose a persentative path across the area you want to measure for groundcover.
- Hold the wire at arm's lenght and shoulder height.
- Looking straight ahad along transect line, take two steps along thct lintwo stps transectalong.
- After a second step, while still looking ahad, lower the point of the wire to the grounnd.
- After the wire has connected to the grounnd, look down and recor presence (yes) or or absence (no) of surface cover directly unnder the point of the wire.
- Repeat at stps 4 - 7 until yontil you have recorded 25 sample points (or more) along the transect.
- The percentage groundcover = number of 'yes' points divided by total number of points, then multiply 100.
- Testing soils, plants and animals for health - a guide for land owners and managers in the Mt Lofty Ranges and Grazing
in the Mt Lofty Ranges - the land management issues are available from Natural Resource Centres in the Mt Lofty Ranges and PIRSA offices.
- Land Management Program advisers based in the Mt Lofty Ranges: www.amlrnrm.sa.gov.au/services.html
- Soil Conservation Board District Plans (being incorporated into Natural Resources Management Board NRM Plans)
- Legislation: www.dwlbc.sa.gov.au/legislation.html
- Assessing surface cover - PIRSA Leaflet
- Hoofprints - A manual for Horse Property Management - J. Foyel, Primary Industries SA. Agdex 461/10
- A Legal guide for South Australian primary producers - SA Law Society, available from PIRSA offices, Natural Resource Centres (but note some legislation referred to is now superseded)
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