Managing Transient Salinity with Chaff

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Video Transcript

My name is Chris and I’m an agronomist on the Northern Yorke Peninsula. I’m also chairperson of a local farmer group called the Northern Sustainable Soils and I’m here today to show you how to manage your transient salinity. I’d say most farmers do have a salinity problem. It affects both their profitability as well as their sustainability.

The lack of plant establishment leads to yield losses, but it also leads to soil being exposed and therefore erosion and evaporation through this bare earth also increases the salty patches. Saline areas are identified throughout the growing season as areas that have poor establishment of crop, and at harvest time there is little crop if any in these areas.

Salt Competing With Grain for Moisture

This is predominately due to the salt competing for moisture with the grain at seeding, and dehydrating the grain so the crop never establishes in this area. On the NYP, we’re looking at managing transient salinity by spreading chaff across these affected patches. Chaff is the byproduct out of a header with is collected in a chaff cart, it’s very fine organic matter, which consists mainly of weed seeds but also very fine stubble that is broken up through the header.

Using Chaff Carts for Transportation of Chaff to Saline Patches

It’s collected in a piece of machinery called a chaff cart at harvest. After harvest, in the autumn period leading into seeding, this chaff is then transported to the saline patches and spread at a thickness of, and aim of about two inches in thickness is what we’re trying to achieve. The chaff then at seeding time acts as a mulch, which reduces evaporation, leaving more moisture in the soil for the seed which then establishes correctly rather than the salt dehydrating the seeds by grabbing that moisture from the actual grain.

Farmers on the Northern York Peninsula have been trialling this technique for the last four years. Yield increases have been anywhere up to four times the yield on dry seasons and one and a half times the yield in those wetter seasons. Additional benefits from the spreading of chaff on these saline areas include reduction in erosion and increased organic matter.

So to sum up, similar to pea straw on your garden, the mulching effect of the chaff on the saline patches, retains more moisture, allows better plant establishment at sowing, and therefore more grain in the bin at harvest.

Northern Sustainable Soils’ Chris Davey discusses using chaff to manage transient salinity.

This video was produced through the Ag Excellence Social Media Project and funded through the Australian Government’s Caring for Our Country initiative.

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