Optimising the potential of autumn sown pastures in the tablelands pasture systems can be critical in overcoming the winter feed gap, leading to better livestock performance and profitability.
Grazing systems need to identify several key factors in order to maximise the grazing benefits from autumn sown pastures.
Nitrogen (N) - Nitrogen is the most common fertiliser used to increase pasture production and this is mainly applied by the product called Urea. When applying nitrogen to pastures, it is important to consider the following factors such as; that the pastures need to be actively growing, that the soils should not be waterlogged and that the fertiliser is best applied within three days of grazing or slashing. (NSWDPI, 2006).
Phosphorus (P) - Phosphorus is frequently a limiting nutrient to the growth of pastures. Phosphorus fertilisers can be applied to dry soil and split applications are preferable when using heavy rates. Highly productive temperate pastures require a soil test Colwell P of at least 75 mg/kg, for medium production the result should be 50 mg/kg (NSWDPI, 2006). Having low Colwell P levels may create favorable conditions for weeds and less productive pasture plants therefore limiting pasture production.
Potassium (K) - A large store of potassium is available in most soils. Potassium deficiency usually arises when plant removal is high. Hay and silage production removes large amounts of potassium from the soil. Potassium is relocated around the farm in dung and urine and should be replaced in areas of depletion. (NSWDPI, 2006).
Sulphur (S) – Sulphur can be the forgotten nutrient as many fertilisers have small amounts available. Single superphosphate is the most common fertiliser to supply sulphur to pastures and Gypsum supplies sulphur and calcium (Ca) to the soil.
Depending on how nutrients are removed determines how much and what type of fertiliser needs to be applied to maintain production. Nutrients removed from paddocks through milk by dairy cows are different to those removed by wool production or live weight gain in sheep and beef.
Key Tips:
Good pasture production requires good soil fertility and achieving this means applying fertilisers that have the correct nutrients for the pasture you are growing and that replaces the nutrients removed by your farming system.
For more information please contact our Stephen Pasture Seeds or AusWest Seeds team.
References
Incitec Pivot, 2011.
http://www.incitecpivotfertilisers.com.au/en/Products%20and%20Services/Agriculture%20Industry/~/media/Files/Productive%20Pastures%2012pp%207870proof12.ashx
NSWDPI, 2006
http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0008/166562/Fertilisers-for-pastures.pdf
University of Georgia
http://extension.uga.edu/publications/detail.cfm?number=B1346