Slender serradella Ornithopus pinnatus

Slender serradella
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NOTE: The information in this Agnote must be read in conjunction with Introduction to selecting and using pastures in NSW, which covers information on areas of adaptation, sources of variability, species mixtures, and important issues related to animal health and the conservation of native vegetation.

Pasture type and use	Annual legume with main growth in winter and especially spring. Mainly used as a pasture plant, and suited for grazing, hay or silage. Particularly tolerant of acid soils. It has good tolerance to waterlogged conditions.
Area of adaptation	North West Slopes, Central West Slopes, Northern Tablelands, Central Tablelands, Southern Tablelands. It may suit some coastal areas.
Min. average annual rainfall	400 mm (southern NSW) to 450 mm (northern NSW).
Advantages	Serradella with best tolerance to waterlogged conditions. A nutritious, palatable, deep-rooted, persistent legume. Suits many soils which are too acid for other legumes. Ideal for sowing to cover wet areas in mix with yellow serradella. Low bloat risk. Extremely tolerant of aphids (unlike sub clover). Can tolerate heavy grazing. A very high level of hard seed, enhancing persistence. Compatible with summer-growing perennial grasses. If well managed can compete well with weeds. Makes good quality hay and silage. Contributes to soil nitrogen. Some tolerance to redlegged earth mite and blue oat mite. Tolerates high levels of soil aluminium and low pH. However, may respond to lime in very acid soil. Good tolerance to most diseases affecting annual legumes.
Disadvantages	Not suited to clay or clay loam soils, but suits light-textured soils with relatively shallow impervious subsoils that may experience periodic waterlogging. Inferior to yellow serradella for autumn/winter growth on well-drained soils. Being an annual, requires companion summer-growing species for all-year-round paddock production. Requires good soil fertility for best production. Early establishment can be slow if sowing with ‘hard seed’ and conservative sowing rates. Susceptible to pests such as lucerne flea and heliothis.
Soil requirements	Does well on shallow (40–80 cm), poorly drained, lighter to medium loam soils. Tolerant of soil aluminium up to 30% of CEC. Tolerant of low pH (Ca) up to 4.0–7.0. Suited to hard-setting (e.g. sodic) but waterlogged-prone soils. Adequate phosphorus, sulfur and molybdenum required.
Varieties	Jebala (mid-season maturity) McFarlanes
Sowing rate	1–3 kg/ha. Often sown with other legumes (e.g. yellow serradella and sub clover) because of soil type variability over a paddock. Seed is very small.
Sowing time	Autumn — late March through to early June.
Companion species	Other winter legumes (yellow serradella, sub clover, arrowleaf clover, Persian clover, balansa clover) on variable soil paddocks, and a summer-growing perennial grass species.
Inoculation	Group G. Lime pelleting is desirable.
Major nutrient deficiencies	Phosphorus, sulfur, molybdenum.
Main insect pests	Blue oat mite (some tolerance), redlegged earth mite (some tolerance), lucerne flea, vegetable weevil, jassids, Heliothis punctigera (native bud worm).
Main diseases	Very few disease problems yet observed. Potential diseases include brown leaf spot (Pleiochaeta setosa), grey mould (Botrytis cinerea), anthracnose, and cercospora fungus.
Management	Suited to moderate set stocking as well as rotational grazing. Can be damaged if heavily grazed following a long period of regrowth resulting in rank growth. It is important to graze down dry summer material by early autumn to around 1–1.5 t/ha dry matter to encourage good autumn germination. Do not graze too hard during flowering, especially until seed reserves are adequate.
Livestock disorders of particular note	No problems reported.
Additional tips	Sowing seed shallow and controlling weeds will generally ensure faster establishment.
Further information	Agfact P2.5.23 Serradella. Weed Control in Lucerne and Pastures 1998/99.

Acknowledgments

Advice on livestock health disorders was provided by Dr Chris Bourke, Principal Research Scientist, NSW Agriculture, Orange. His contribution is gratefully acknowledged.

Photo: M. Davies, Department of Agriculture, Western Australia.