Serradella saves $90/ha

With almost a 1t/ha of plant biomass at this early stage in the season, Margarita serradella crops are looking the goods on the Brookton property of Colin and Anna Butcher.

But according to Mr Butcher, what is happening beneath the soil is even more important to his overall cropping program.

He estimates the use of both Margarita serradella and biserrula pastures can save him up to $90/ha in nitrogen costs, which in lean years makes all the difference when it comes to farm profitability.

A field day at the Butcher property in Brookton last week, run by the Department of Agriculture and Food in conjunction with Murdoch University, demonstrated how both serradella and biserrula crops, while being a highly nutritious feed supplement, can also reduce business risk and improve soil fertility.

Mr Butcher first planted biserrula three years ago, and serradella four years ago, and said the self- regenerating legumes were now an integral part of his cropping rotation.

“In essence, we are growing our own nitrogen for our cropping program, that is the No. 1 priority for our business,” he said.

“But another positive outcome is that we have high-quality sheep feed that enables us to run a low-cost profitable sheep flock as part of the business.”

The Butchers run a 3500 Dorper flock, which are now in prime condition after the unseasonal wet weather throughout late March and April.

But Mr Butcher said the hard-seeded serradellas and biserrulas would cope well in dryer autumns, where they could withstand a false break.

Fifteen GRDC-funded trials have been run throughout the cropping region over the past four years looking at the value of serradellas and biserrulas to subsequent wheat crops.

These trials have demonstrated that, apart from the five units of nitrogen applied upfront at seeding time, nitrogen application becomes unnecessary, at least for the first year after the use of legume pasture such as serradella or biserrula.

DAFWA senior research scientist Angelo Loi said this year’s magnificent Margarita serradella crop on the Butcher property would set the business up well in terms of soil nitrogen for several years.

He said the crops also provided excellent high-quality stock feed during the autumn period when availability of feedstocks were low or just crop stubble.

“The Butchers are now able to run sheep at almost double the stocking rate for the area because of these pastures crops, and the sheep are in incredible condition for this time of the year,” he said.

Mr Loi said even farm businesses without stock should consider pastures as a break crop for nitrogen production.

“On most farming properties, some of the paddocks are usually left in fallow,” he said.

“In some scenarios, you can’t or don’t plant a legume, so the serradella and biserrula pastures are an excellent option to improve soil fertility for subsequent cereal crops.”

According to ALOSCA Technologies general manager Chris Poole, a dry granular inoculant should be applied to a hard-seeded summer-sown pasture crop.

“Farmers might use a peat-based inoculant for pastures, but since hard-seeded serradella requires summer sowing, the Rhizobium (root nodule bacteria) in a peat-based inoculant would perish, and so it’s important to use the dry granular product,” he said.

“The dry granular product also has advantages to the peat-based inoculants, because it doesn’t dry out during application, it will survive in the furrow waiting for moisture, and is easy to handle during sowing.”