Raised bed trial results from WA

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Beverley farmer Harvey Morrell has found that using raised beds in a paddock susceptible to waterlogging has vastly improved yields.

Raised beds to control winter waterlogging have yielded excellent results in the first year of full trials in Western Australia.

Agriculture WA researcher Greg Hamilton said raised beds at four large-scale trial sites showed a combined 35 per cent greater yield than control plots in the same paddocks. Yield improvements ranged from 22 to 47 per cent over control crops using conventional methods in the same paddock.

The raised beds draw excess water from the soil and drain it from the paddocks in furrows.

Treatments

Three of the sites have two treatments — raised beds with no-till established crops (gypsum used as required) and an untreated surface with direct-drilled crops as a control.

The fourth site at Cranbrook is a fully instrumented research site with four treatments: raised beds with no-till establishment with and without stubble grazing, and an untreated surface with no-till establishment with and without stubble grazing.

Mr Hamilton said the first year's results showed substantially improved productivity despite the fact June rainfall at all sites was substantially below average.

"The finishing rains in spring were also low, particularly at Esperance and Cranbrook, although the August rainfall was above-average at these two sites.

"To increase yield so much was surprising given the dry season, but it indicated that the better soil structure and deep root zone had a positive effect," Mr Hamilton said.

"Where waterlogging occurred, both visual observations and measurements of crop growth and soil water parameters confirmed that raised beds prevented waterlogging.

"The use of raised beds also develops better soil management practices, which create and maintain good hydraulic and aeration properties in the root zones of crops," he said. (See related findings this page from Southern Farming Systems.)

The research will continue for another four years to develop a drainage theory identifying soil conditions and drain spacing to reduce waterlogging and improve yield on susceptible ground.

Region North, South, West