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To view the previous 12
months issues please use the links above or
use the Backcopies link to view ALL previous issues
The GREEN HORSE
- sustainable horsekeeping
JUNE/JULY 2007
Vol 29-1
In the Current Issue of The Green Horse you will find the following articles:
Information Exchange - Reader’s Tips, Views
and Questions
Horse Trails Study
Things To Do .... June/July
Deeds, Steeds and Weeds. Native Grasslands
Growing Equine Herbs - Bilberry by
Fiona Adams
Pasture Renovation - Part Two by
Chris Ferriera and Tracey Bell
Weed Watch - Bathurst Burr by Nicola Field
Birth Control For Wild Horses
Electric Fences - Energisers and Solar Panels.
PASTURE RENOVATION by Chris Ferreira and Tracey Bell
In
the last part of the series, we cover the final strategies for improving
those tired old paddocks.
Keeping horses while still maintaining green, well covered paddocks is a balancing act, as many a property manager will tell you, however it is possible with some careful planning. Following on from the first part in issue number 67, where we discussed tips number one to four, here are first aid tips number five to ten.
Windbreaks will help to stave off the worst of winds which destroy moisture in pasture, keeping paddocks greener for longer.
5. Windbreaks
Pretty much every property that I have seen can do with some ‘strategic’
revegetation. In most cases this will mean carefully designed windbreaks
to stave off the worst effects of the winds that would otherwise blow
across your paddocks, sucking the precious moisture from your soil and
your plants. Good windbreaks will reduce this impact by anywhere from
15 to 30 percent, meaning that your pastures will stay greener for longer
and, if you have irrigation, the watering is much more effective as the
water will hit the ground and be absorbed rather than being whisked away
in the hot dry breeze while still airborne.
In previous articles we have talked about suitable species and designs
but it is worth reiterating that you should choose species that are not
overly aggressive and fast growing as they will usually then impact on
our pasture in the years ahead. Good tree species to consider that won’t
outcompete adjacent pasture are Casuarinas, Corymbia Maculata (Spotted
Gum) and Callitris species. For more species relevant to your area, try
your local Landcare Group or Department of Agriculture.
6. Over-watering or over-fertilising - doing
more harm than good
Landholders often think the best way to help tired old paddocks is to
put heaps of water and fertiliser on but, as I have explained above, this
can often do more harm than good (and waste precious resources) unless
some critical steps are carried out first. Overwatering, best described
as putting more than 15 to 20 millimetres twice a week on your paddocks,
will simply create shallow rooted pasture - weak pasture that is not resilient
- and will flush precious nutrients past the root zone. Over-fertilising
(ie more than 50 grams per metre square twice a year) will just create
‘leggy’ growth that will be more susceptible to stresses of drought, frost
and flood and it will mean excess nutrients are leached into groundwater
and rivers.
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7. Reseeding
Reseed paddocks with little or no cover using a drought tolerant mix. |
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8. Cover up and rest the bare patches
If you can, cover up bare and degraded patches that are being rested.
This cover can be anything from good quality but old hay or straw, thin
bands of manure or compost. (Compost need only be one centimetre thick
to do the job.) This cover will help kickstart the soil improvement process
and will give cover and support to any grasses trying recover and/or establish
on the site. You will be amazed just how quickly this process rejuvenates
the growth in these areas.
9. Creating the ‘level playing field’ - the benefits
of even length pasture
If you have good cover of pasture then the problem often faced is that
there is uneven grazing by the stock so that you will end up with ‘roughs’
or patches they wont eat and ‘lows’ where they will graze to the point
of baring the land. You will need to slash or mow these paddocks to have
even height pasture and thus more even grazing.
10. Bring your soil back to life - compost or
manure, fish or seaweed sprays
Never underestimate the value of these biological agents to reinvigorate
your pasture and soil. Regular doses will keep the pasture vigorous and
help it overcome deficiencies in the soil such as compaction and nutrient
imbalances. So paddocks don’t need to be old, tired and bare. Some careful
management and planning can keep them looking good, with a healthy cover
and also some valuable grazing-potential throughout the year. Good luck!
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A recent study undertaken by Stith T. Gower of the Department of Forest Ecology and Management at the University of Wisconsin-Madison asks the question whether horses spread non-native plants (ie weeds,) on trails. The study, funded by the American Endurance Ride Conference (www.aerc.org) is of great interest to the many horse riders in Australia who enjoy riding on ever-threatened tracks and bush trails. A new study claims horses do not appear to be a major source for the introduction of non-native species - often a reason given by government agencies for preventing horseriders’ access to trails. |
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Whether plant and weed seeds contained in horse manure, hooves, and hay can cause non-native plant species (plants that were introduced to that ecosystem but do not grow there naturally) to spread along trails and into parks and forests is an ecological question that often arises.
Dr Gower, PhD, has determined that while there are seeds from weed and non-native plant species in horse manure and hay, the plants that result don’t survive or spread on trails. Therefore, horses do not appear to be a major source for the introduction of nonnative species as is often claimed by various government and political departments when trying to stop horseriders’ access to trails.
“Non-native plant species pose a serious ecological and economic threat to managed and natural ecosystems,” said Dr Gower. “Therefore, there is a great need to identify major sources for the introduction of non-native species and implement management plans to reduce or eliminate their introduction. Horses have been suggested to be an important source for the introduction of non-native plant species along trails, but the data are largely anecdotal.”
The objectives of two studies were to determine if horse hay, manure, and hoof debris samples contained seeds from non-native species, and if so, whether their seeds would germinate and establish on the trails.
Gower took samples of horse hay, manure, and hoof debris from 12 to 24 horses at each of five American Endurance Ride Conference (AERC) rides held in North Carolina, Kentucky, Illinois, Wisconsin, and Michigan. Subsets of these samples were sown in potting buckets and grown outdoors in ideal conditions in Madison. In addition, samples from the horses at each ride were placed back on the horse trail.
On average, non-native plant species germinated from 5.2 percent of the hay samples placed in the potting buckets, indicating horse hay contains seeds from non-native plant species. However, only three of the 288 hay, manure, and hoof debris samples placed on the horse trail contained plants after the first growing season, and no surviving plants were observed after the second season.
Dr Gower also did vegetation surveys along 50 metre survey lines perpendicular to horse and hiking (horses not permitted) trails at three of the five sites to compare species composition of native and non-native plants. He wanted to determine if newly introduced plant species were moving into ecosystems adjacent to the horse trails and trails that prohibited horses.
Species composition and percent of total non-native plant species did not differ between horse and hiker trails, and the non-native plant species always occurred within two metres of the trail. Other potential sources for non-native species might be birds, he said. “Many studies have observed that trails and roads (of all uses) facilitate the establishment of non-native species,” added Dr Gower.
The results of this and other studies demonstrate that horse hay and manure contains seeds of non-native plant species, but native and non-native plant species rarely become established on horse trails because of the adverse effects of harsh environmental conditions and frequent disturbance on seedling establishment.
This is welcome news for those campaigning for trail access in Australia, given that conditions here should mirror those in the United States.
For more information about the study, e-mail Dr Gower at stgower@wisc.edu.