Soil type influences what species are best suited to be grown in a paddock. Perennial grass species vary in tolerance to soil acidity and aluminum levels. For example, cocksfoots are more tolerant of acid soils than fescues. Soils with high clay levels and prone to water-logging suit species such as tall fescue and phalaris, whereas free draining soils are favoured by cocksfoots and bromes. Table 1 provides more information on species and their preferred soil type.
Rainfall pattern (summer dominant, winter dominant or uniform), affects when pastures will be productive and which species will be best suited to a region. Plants need the most soil moisture during active growth, so seasonal growth of pasture species should be matched to rainfall. For example growing a summer active cocksfoot is going to grow best in a summer dominant rainfall area because the rainfall occurs when the plant is actively trying to grow. If the summer active cocksfoot was planted in an area with hot, dry summers it would not persist due to lack of moisture.
Temperate perennial grasses prefer temperatures between 12 and 30ᵒC for growing (DPI, 2016). Perennial ryegrass is most productive at 20ᵒC (Hunt & Halligan, 1981) and production declines at 24ᵒC (Agricom, 2017). The optimum growing temperature for tall fescue is higher than ryegrass, 26ᵒC and active growth continues into the mid 30ᵒC (Agricom, 2017). This means tall fescue is better adapted to warmer springs and summers than perennial ryegrass. Most temperate grass species will tolerate frost, however minimal growth occurs once temperatures fall below 8ᵒC (DPI, 2016).
Table 1: Preferred environmental conditions for perennial temperate grass species. (Compiled from AusWest Seeds Pasture guide; DPI, 2016)
|Species||Varieties||Minimum Rainfall||Soil Type||Growing Season||Other|
|Summer active cocksfoot||Savvy
|500-700 mm||Well drained, tolerant of acidity||Spring, Summer, Autumn||Slow to establish but can persist for many years. Well suited for mixes with legumes and herbs|
|Summer active tall fescue||Hummer
|650-700 mm||Moderate to heavy clays, tolerant of water logging||Spring, Summer, Autumn||Highly productive in spring and requires good grazing management at this time. Actively grows at higher temperatures than ryegrass. Well suited for mixes with legumes and herbs.|
|Phalaris||Australian II, Atlas PG, Holdfast GT||400-500 mm||Moderate to heavy clays, some varieties tolerant of acidity||Depends on variety||There are both winter dormant and winter active types of phalaris. Well suited for mixes with cocksfoots, fescues, legumes and herbs.|
|Perennial ryegrass||Kingsgate, Prospect, One50, Halo||60-700 mm||Suited to most soil types||Autumn, Winter, Spring||Quicker to establish than other perennial grasses. High feed quality. New endophytes provide plant benefits with minimal impact on animals. Well suited for mixes with clovers.|
|Prairie grass/bromes||Atom, Gala, Exceltas||600-650mm||Well drained fertile soils||All year round. Highest in spring||Maintains feed quality in reproductive phase. Well suited for mixes with legumes and herbs.|
When is your feed shortage? Which pasture species are going to fill or reduce your feed gap? Remembering that the amount of pasture growth will be influenced by all of the factors discussed above.
When choosing a pasture to sow environmental factors and plant factors should be considered before choosing a variety. Think about what species is going to grow in your environment and give you feed when you need it.
Agricom (2017). Tall fescue management guide. Retrieved from http://agricom.com.au/assets/Uploads/Tall-Fescue-Management-Guide-A4-Aus.pdf
AusWest Seeds (2018). Pasture Reference guide.
Department of Primary Industries (DPI)(2016). Temperate perennial pasture establishment guide. Steps to ensure success. Retrieved from http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0004/679126/temperate-perennial-pasture-establishment-guide.pdf
AusWest Pasture guide
DPI Temperate perennial pasture establishment guide: http://www.dpi.nsw.gov.au/__data/assets/pdf_file/0004/679126/temperate-perennial-pasture-establishment-guide.pdf