Boost to pasture legume seed supplies following bumper harvest

Some of these have been tested and promoted, including by this column and columnist, for more than 40 years.

That's not to say they don't deserve more publicity and, in my view, also far more extensive growing.

Newer varieties, in some cases, new technology such as companion rhizobia delivery and new approaches to seed quality are part of these species deserving new interest. Also, seed availability is better.

Long-term Western Australian seed supplier Neil Ballard, is now concentrating his business on seed cleaning and processing.

He recently informed me supplies of various serradella varieties and biserrula, from last year's harvest (generally processed after our sowing requirements) are excellent, with some growers harvesting several hundred tonnes per hectare of seed.

Several NSW growers are also likely to harvest seed this summer.

The first commercial growers of serradella in eastern Australia occurred in 1975 (see publication The History of serradella in NSW) on central west properties at Binnaway, owned by the late Stan King and now retired Col Carslake.

These sowings followed successful research conducted on several properties where serradella proved to be the first successful legume on soils acidic in the top as well as subsoil.

Pitman was the original serradella variety and has been succeeded by several lines with considerable productivity improvement as well as more maturity versatility.

SerraMax is the most recent yellow serradella variety, with commercial seed likely to be available for sowing next autumn.

In several respects, it is similar to King, an excellent early maturing variety, but with likely greater seed availability.

Many WA landholders, and a few NSW ones, are adopting summer sowing of graded but not processed serradella seed, commonly harvested on their own or nearby farms.

Read more: Stripe rust challenges wheat and triticale varieties in 2022

A majority of unprocessed serradella seed (as well as seed of other species including biserrula, gland, bladder and arrowleaf clover) is "hard", but if sown in summer, much of it converts to "soft" seed over summer and is ready to germinate on the first autumn rains.

Commonly these sowing will be ahead of seed sown on opening autumn rains and go on to produce far more winter and spring feed.

Increasingly adopted serradella (as well as species like biserrula) establishment technology is to use clay-based pellets with appropriate rhizobia infused into them (Alosca pellets).

Based on WA research, rhizobia survives successfully in these pellets for a considerable time, whereas applied lime and glue techniques have a short survival period.

Hence this methodology combines well with summer sowing.

Many of the so-called newer winter legumes can substantially lift pasture productivity, combined with extra soil nitrogen and organic matter build-up.

Commonly, soils are variable across a paddock, with some species suiting one area, for example, deeper acidic loams or sandy areas, and others suiting less acidic areas.

In our own property's case when establishing a new pasture, for example, after a cropping phase, we will include serradella and biserrula for the more acid soils, sub clover for less acid ones, and gland and balansa for areas more prone to waterlogging.

Unprocessed seed of legumes like serradella and biserrula, can be included with sowing of tropical grasses in spring or early to mid-summer. Including Alosca pellets helps ensure rhizobia also survives to colonise on autumn germinating legumes.

There are lots of other reasons to include so-called new winter legumes in the pasture mix.

For example, a serradella paddock or two is great in a year with lush winter and spring growth because of its largely non-bloating risks.

Serradella also tends to hang on much later into spring and even early summer providing better quality for a longer period.

It is also more tolerant of aphids should they become a spring problem.

Next week: Weed control strategies based on species and extent of infestations.