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Beef Breeder MANUAL
9.3. Establishing Pastures and Forages
9.3.1. Preparation for Sowing
Sowing forages or a pasture involves good planning in the year before the pasture is sown. During this period,
a weed control strategy can be implemented that will enable the newly sown pasture to establish under the
best conditions, and minimise the establishment of weeds. The control strategy may include management
activities that prevent the existing pasture setting seed, including;
• Cutting the existing pasture for silage • Hard grazing of pasture regrowth
• Use of herbicides • Cultivation.
Pastures and forages must be sown into a well prepared seedbed that enables good soil to seed contact to
maximise germination. The seedbed can be either cultivated or tilled, or no-till sowing methods can be
employed on areas that have had good chemical control of weeds applied beforehand. In both cases,
good attention must be paid to the sowing depth of the seed to ensure good emergence.
For efective germination, the optimum sowing conditions are into a moist soil bed, and to have the
good contact between the seed and the soil. This is best achieved with a ine, irm seedbed.
9.3.2. Seed Quality
To ensure success when sowing new pasture or forage seeds, a few important steps should be followed. These
include ensuring that seed is;
a True to variety: Be sure that the seed is really that of the variety you wish to plant. The best way to do
this is to obtain seed from a reputable source and to check the label
b High quality: Use only high quality seed to establish the pasture. Quality is measured in terms of purity
and level of germination. Try to obtain a recent seed analysis statement for the seed you are planning to
sow, since this will show these details. Pay special attention to the weed seed in the sample since you
do not want to introduce new, potentially serious weeds into your system. The analysis will also give
germination details for the sample, which includes the percentage germinable and hard seed. If the
seed has 50 viable seed, this indicates poor seed health, and usually results in poor ield germination
and establishment
c Low dormancy: Many grasses are subject to post- harvest dormancy, which means germination
improves, sometimes for over 12 months after harvest
d Stored favourably: It may be necessary to store seed for a period before sowing. Germination can decline
rapidly if seed is stored at high temperature and humidity, so there are some basic rules to follow if
seed quality is to be maintained:
• Ensure seed has a moisture level 10 before storage. Seed dies faster with increasing seed
moisture • Keep seed in cool, dry conditions, since the
higher the temperature and the relative humidity, the more rapid is the decline in seed quality.
While refrigerators may be cool, they also operate at high relative humidity and may not
improve keeping quality of seed. Air conditioning is a better alternative
• Smaller seeds need special care since they inherently tend to have shorter shelf life
• Protect from seed-eating vermin such as insects and mice
• Check germination before planting e Treated if required:
i Scariication: The seedcoat testa of legumes is often impermeable to water, thus slowing
germination. This “hard seed” gradually breaks down with weathering, allowing the seed to
germinate. If the hard seed level is too high, it can result in poor germination immediately
post-sowing when it is important for the sown species to compete with regenerating weeds.
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Cold Winter Climates
The level of hard-seededness can be reduced by scarifying the seed coat being careful not to
damage the embryo ii Inoculation: For pasture legumes to be useful,
they require the presence in the soil of a strain of nitrogen-ixing bacteria rhizobium suited to an
efective symbiosis in the legume root nodules Fig. 9.4.
Some legumes are very speciic in their rhizobium demands. Where there is doubt that a suitable
strain of rhizobium exists in the soil, a culture of the bacterium is introduced, usually on the seed in the
form of a peat culture a black powder, in a process called inoculation. Peat cultures should be kept well
sealed, moderately cool, and out of the sunlight until they are used. The rhizobial culture is mixed into a
slurry with an inert glue such as methyl cellulose and mixed with the seed to provide a thin coating over
the seed. The seed should then be spread out in the shade to dry before sowing. Seed should be sown as
soon after inoculation as possible. If a commercial rhizobium culture is not available, seed should be
mixed with soil from around a vigorous plant of the same species. This soil will contain enough of
the suitable strain of rhizobium to achieve efective nodulation.
9.3.3. Post-Emergence
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