Wheat, canola: lime adds to yields

Economic analysis of long-term lime trials indicates that liming acid soils can be very profitable, according to Agriculture Western Australia (AGWEST) research officer Mike O'Connell.

Mr O'Connell said research trials had shown large yield benefits more than 10 years after liming.

"Data from two long-term trials at Varley and Wongan Hills showed that recent yield responses in wheat and canola where lime had been applied to acidic soils were very encouraging, and demonstrated the profitability of managing acidity in Western Australia and probably elsewhere.

"A lime trial at Varley produced gains over a four-year rotation (wheat-canola-wheat- lupins) from the application of 1-2 t/ha of lime, which outweighed the initial cost."

AGWEST researcher Chris Gazey said although recent wheat and canola yields had been very encouraging, he cautioned that if gains were to be made from managing soil acidity, farmers needed to be aware of other factors such as adequate nutrient and weed management.

Is transport a major cost barrier?

Transporting lime from the pit to the farm accounts for a big part of the cost of a liming program. This work looked at the costs of liming paddocks 50, 150, 250 and 300 km from the nearest source of industry-standard lime. "The results indicated that increasing transport costs had only a small impact on the profitability of liming," he said.

"Even though high transport costs will cause a decrease in gross margins in the year that lime is applied, the costs are incurred infrequently, perhaps once every five to 10 years."

"In the analysis, gross margins over the rotation were always higher in limed than in unlimed paddocks, even with the longest transport distances. Distances would have to be in excess of 700 km before liming became unprofitable."

Contact: Mr Mike O'Connell 08 9368 3427 or Mr Chris Gazey 08 9368 3633