Faba beans with sugar prove perfect in rotation

Keen to improve their soil health rather than producing an export product brothers John and David Haynes followed the lead of their brother-in-law Fred Faulkner, Dobies Bight via Casino who had used them in rotation with corn as an alternative to winter fallow.

Following advice from their agronomist, Tony Gordon, the Haynes have now grown faba beans on heavy alluvial lower river soil for the past four years, though it took a couple seasons to get it right.

“We were used to growing soybeans which are placed 25mm deep,” recalled John. “But we found out as we went that faba beans need to be planted at 75mm.”

The brothers use a John Deere MaxEmerge vacuum planter which is gentler than air seeders and sow at 100kg/ha or 25 seeds to the square metre.

They have adopted no-till planting for three years now and find it works well even in the heavy coastal soils.

This winter’s faba bean rotation was particularly trying with heavy rain in early June – between 200-400mm falling between Woodburn and the coast. Faba beans that had been planted 10 days earlier survived but those planted at the time of the heavy rain failed.

A follow up heavy weather event occurred later that month and July and August have brought more rain and wind.

But you can see from the photo that the faba beans not only survived, they thrived with zero inputs from fertilisers and insecticides. The plants themselves successfully shaded out competing weeds.

“There’s a tiny bit of chocolate spot,” said John pointing out a rare tainted leaf. “but the plants looked after themselves.”

With sugar prices lucrative at the moment, the brothers’ focus is on that crop, which is notoriously hungry for nitrogen so the faba bean rotation helps increase their soil’s potential ahead of planting.

This particular paddock in the photograph had faba beans last winter before soybeans last summer and after this third legume crop – which will be ploughed in before pod set – the brothers will plant sugar cane which is hungry for nutrient.

It is a shame the domestic market for fabas is so tiny – a bit is sold for livestock feed to be combined with corn and a few small green pods are sold fresh but the vast majority are exported to Egypt and this year civil strife in that country has put paid to that outlet.

“But we are not in the primary business of producing faba beans,” explains agronomist Tony Gordon.

“Rather, we are interested in soil health through crop rotation.” 

THE real purpose of faba beans in coastal rotation with sugar cane is the legume’s ability to deliver real value when it comes to soil conditioning.

If faba beans are sprayed out with glyphosate prior to seed formation their maximum nutritional potential is returned to the soil, says agronomist Tony Gordon based at Eltham via Lismore.

And that final production phase also demands the greatest uptake of water so returning the legume to the ground will save soil moisture for the next crop.

Mr Gordon says faba beans typically place 100 units of nitrogen into the soil through root nodules, which when compared to urea at 46 per cent nitrogen equals about $100/ha at today’s prices.

The bean also pulls potassium and to a lesser extent phosphorous from the soil profile making it available for the next crop – the purple tinge to the dying bean stalk indicates potassium.

The other benefit with faba beans is that their hollow stalk quickly breaks down after mulching which reduces the amount of tangle when a seeder or tillage equipment makes the next pass over the top.

Faba beans act as tell-tale indicators for soil acidity as they don’t like growing in pH below 5.2.

“If your faba beans don’t grow strongly that may be a sign that your soil may need a dose of lime,” said Mr Gordon, who cut his teeth on western district crops.