Other management considerations
The loss of pasture production after spraying is arguably the greatest downside to winter cleaning. Therefore, applying the treatment in years of adequate or abundant pasture growth will lessen the short-term negative effects. Other approaches include only treating one or two paddocks a year.
It is recommended to undertake a whole-farm feed budget to understand and manage the potential loss of feed. The overall cost of winter cleaning increases dramatically if the loss of feed is to be replaced by supplementary feeding or through boosting growth on other paddocks with nitrogen or gibberellic acid.
Another major consideration is to ensure there are sufficient desirable plants to fill the gaps. This may be hard to achieve if the desirable grass or sub-clover content is low before treatment or if other competitive weeds, such as capeweed or erodium, are also present.
Before deciding to winter clean, consider these questions:
- Are there sufficient plants to fill the bare spaces?
- Can appropriate grazing management be applied?
- Are soil conditions favourable for the growth of desired species?
- Is competition from broadleaf weeds minimal?
While winter cleaning can be highly effective in reducing annual grasses in the year of treatment, some seed carry-over is likely. If there is insufficient competition within the pasture, prolific-seeding annual grasses can quickly rebuild plant numbers.
Different tactics, such as silage, spray-topping or crash grazing at seed head emergence may be required to minimise silver grass seeding in the following seasons.