Vetch is under evaluation for its dual benefits of nitrogen supply and weed management on about 100 hectares of Peter and Robert Allen’s southern New South Wales farm.

The Allens’ farm is located 128 kilometres north-east of Wagga Wagga near Grogan on highly alkaline and dispersive soils.

Peter feels there are no reliable and high value pulse crops they can grow on their difficult-to-manage soil types. Faba beans and peas were tried in the past, but were expensive to grow. Newer varieties might be an option to try in the future.

“We want a break crop that is inexpensive to grow and easy to manage,” Peter says.

“Timok vetch has been reasonably good to date, but it has not coped too well in soils affected by transient waterlogging.”

Peter says major rainfall events cause soils on the farm to waterlog because they disperse readily when wet and clay particles block pores in the soil, reducing rainfall infiltration. As the soil dries, a hard crust forms, either on the surface or in the subsoils, which inhibits crop emergence and root proliferation.

To improve rainfall infiltration, Peter and Robert direct drill all of their crops using a tyned seeder set on 254-millimetre row spacings. Wheat is sown after lucerne and clover. The pasture is terminated during autumn, just before planting.

“The main reason we’re growing lucerne is to dry out and crack open our subsoils, which are very dense and reduce roots from accessing moisture stored lower in the soil profile during spring,” Peter says.

“There’s a bit of research out of Victoria which has demonstrated that growing lucerne and terminating it just before sowing a winter crop improves rainfall infiltration and increases plant-available water for following crops.”

Having a mixed-farming enterprise and making use of vetch, which can tolerate drier conditions better than other pulses, is also part of the family’s risk-management strategy.

“Vetch is a versatile crop because it can be grazed, the grain can be harvested for stockfeed or it can be used as a brown manure, which returns organic matter and nitrogen to the soil,” Peter says.

In 2019 and 2020, vetch was planted in a mix with barley. The aim was to terminate the barley early and allow the vetch to keep growing on the barley stubble to improve the ease of harvesting. However, in the favourable conditions in 2020 Peter and Robert decided to harvest the vetch and the barley as both produced seed.

Peter and Robert are participating in GRDC-invested trials exploring deep placement of organic and inorganic amendments to address sodic subsoils and improve crop access to water, particularly in dry springs.

After droughts in 2018 and 2019, Peter says it is critical for research to look at ways that crop roots can tap into water deeper in the soil profile.