Cropping

Salt stress help

By Country News

New research has found that a hormone produced by plants under stress can be applied to crops to alleviate the damage caused by salty soils.

The team of researchers from Western Sydney University and the University of Queensland identified a naturally-occurring chemical in plants that reduces the symptoms of salt stress in plants when applied to soil, enabling the test plants to increase their growth by up to 32 times compared with untreated plants.

Salinity affects more than 220million hectares of the world’s irrigated farming and food-producing land.

Salinity occurs when salty irrigation water is repeatedly applied to crops, leading to progressively increasing levels of salt in the soil which reduces crop yields, increases susceptibility to drought and damages soil microbiology.

The new research has the ability to reduce the damage in crop plants that results from salt, says Western Sydney University Soil Biology and Genomics Postdoctoral Fellow Hongwei Liu.

‘‘We identified a compound called ACC that occurs naturally in plants when they become stressed by drought, heat or salty conditions,’’ Dr Liu said.

By applying ACC to crops planted into salty soils, it created conditions that prevented the formation of the compounds that cause plant damage under salty conditions and increased beneficial soil enzyme and microbial activity.

These effects enabled the plants to cope with the salt and increased the growth of lettuce plants by nearly five times and model plants by more than 30 times.

‘‘There is very significant potential for this compound in enabling us to manage crop production in otherwise-unusable soils,’’ University of Queensland’s Peer Schenk said.

‘‘Growers have traditionally used a range of long-term and slow-acting materials such as gypsum, manures, tillage and other methods to reduce the exposure of plants to the salts in soils but these are costly, frequently ineffective and work to limited benefits over years or decades,’’ Professor Schenk said.

One of the major benefits of ACC is that it is naturally produced by plant roots and therefore contributes to long-term soil health, plant-microbe relationships and carbon storage.