SERRADELLA, biserrula, bladder, gland and arrowleaf clovers have added considerably to pasture productivity and options for a number of southern NSW primary producers including Julie Brien, “Ardnai”, Greenethorpe.
The roles and benefits of these pasture species, in conjunction with older types such as sub clover, lucerne and perennial grasses, will be one of the feature sessions at the coming NSW Grasslands conference in Cowra on July 25-26.
Ms Brien will outline how some of these species, especially serradella, grown widely for seven years on “Ardnai”, have added to profitability of her prime lamb and beef business. She first experimented with them with Central West Local Land Services agronomist Belinda Hackney, who continues to conduct research on her property. A key role of high hard-seed-content species, says Dr Hackney, is their ability to re-establish after two- or three-year cropping phases where legumes are often killed by normal pre-sowing or in-crop herbicides. Several varieties of serradella, biserrula and gland clover have higher levels of hard seed than the hardest-seeded sub clover. High hard seed helps ensure several years carryover of viable seed and fast pasture legume reestablishment after cropping phases.
Ms Brien said while sub clover has for generations been the main annual legume in districts such as Greenethorpe, adding newer species can greatly increase production, especially with their ability to grow well into spring, when commonly sub clover has seeded down and hayed off. Species such as serradella tend to root deeper and faster and commonly survive longer than subs when a dry mid to late autumn follows an early autumn break. Likewise dry and above average spring temperatures often followed by useful later spring rain results in further significant feed and seed plus feed remaining high quality green well into November and even December compared with dried down sub.
For example on “Ardnai” serradella and Bartolo bladder clover, early maturing varieties (around the same start to flowering as Dalkeith sub) will grow and flower far longer than sub if seasonal conditions remain moist and mild. Not only does longer growth add considerably to production for feed but also for silage, hay or seed.
Low-risk or bloat-free status of species such as serradella is also valuable. Reduced risk from disease such as viruses, leaf and root funguses is another feature of the newer species, Dr Hackney said. Diversity of species is valuable should an outbreak of one or more of these diseases be an issue.
Especially appreciated by Julie Brien is the elevated flowering and seed set in legumes including bladder clover, gland clover and serradella, which allows for easy seed harvest. While elevated flowering and seeding requires more grazing care to ensure good seed set (and soil seed reserves) it allows farmers to easily provide for their own seed. Bladder for example has yielded up to a tonne per hectare of seed on “Ardnai”.
Ms Brien believes each species favours slightly different soils, with bladder for example suiting moderately acid ones to those quite alkaline (pH 4.8 upwards to 8.0). Each species has different features, such as yellow serradella being more aphid tolerant. Julie Brien believes including bladder gland and serradella to her pasture adds to long-term legume persistence, as well as productivity. Especially valuable is their ability to persist at good density through a typical medium-term cropping phase.
To attend the grasslands conference visit www.grasslandnsw.com.au or phone David Harbison on 0408 820 467.
Next week: Widening crop sowing window increases reliability of high yields.
- Bob Freebairn is an agricultural consultant based at Coonabarabran. Email robert.freebairn@bigpond.com or phone (0428) 752 149.
