Soil salinity is a major issue for grain growers worldwide. In the United States it is estimated that yield reductions occur due to salinity on approximately 30% of arable land, and in Australia, 67 % of all grain growing areas are affected by this environmental stress. But a new partnership between the University of Connecticut and the Australian Centre for Plant Functional Genomics (ACPFG) is improving the ability of cereal crops to grow in saline conditions.
The technology known as vacuolar pyrophosphates (AVP1) was developed by then Assistant Professor Roberto Gaxiola at the University of Connecticut, in the College of Agriculture and Natural Resources.
Assistant Professor Gaxiola, now a researcher at Arizona State University, developed the AVP1 technology after witnessing farmers in his native Mexico struggle to maintain cereal crop yields.
‘Mexico, like many countries around the world, is facing the soil salinity problem in very productive agricultural areas like the Northwest, where most of the cereal crops are grown. This technology, together with other technologies that work to improve the quality of water used for irrigation, will allow us to grow relevant crops like wheat, barley, corn, and rice in areas of the planet that have been salinized,’ he said.
Dr Stuart Roy, Program Leader at the ACPFG explains how salinity affects plant health. ‘Saline soils affect the growth of plants by reducing shoot growth and interfering with metabolic processes, such as enzyme activities and protein synthesis. Crops grown on saline soils often have significantly reduced grain yields’.
The technology has been licenced by the ACPFG and is showing positive signs in cereal crops grown at ACPFG’s saline field trials.
‘AVP1 technology improves the shoot growth of plants helping them to better survive saline conditions,’ said Dr Roy.
This technology is giving hope to grain growers who have been affected by saline conditions.
Andrew Hansen grows wheat, barley, canola and oats on his farm at Coomandook in the Upper South East region of South Australia. His family has farmed this land for over 60 years.
A small percentage of Andrew’s farm is affected by salinity. ‘The soils in this area are saline because they are affected by a rising underlying water table where you get capillary action of water to the surface during the year which dries out in summer, increasing the salt concentration in the soil. This results in boggy, wet soils,’ he said.
Soil salinity degrades the land and over time can cause areas that were once productive to be less so, sometimes resulting in parts of the farm being entirely unusable. ‘All of the areas now affected by saline soils on my farm used to grow crops 30 to 40 years ago. Back then, these areas were the best cropping areas on the farm. Now they are unproductive and that’s due to the rising water table causing rising salinity levels. These saline areas are now under pasture and are used primarily to feed stock’, said Andrew.
Crops suffer when grown in saline soils and the effects are visible in their appearance. ‘You can see burning off at the leaf tips and you get poor germination. The plants are water logged during winter and later in the year salt residue on the soil leads to plants dying prematurely in spring,’ Andrew explains. ‘The result is about a 50 % reduction in grain yield compared to crops grown on less saline soils. In severe cases it means the loss of full production resulting in larger areas being removed from cropping entirely.’
To manage soil salinity, Andrew uses a number of strategies including pasture production and careful choice of crops to plant in these areas. However, he states, ‘in ideal years when there has been a dry winter and a nice spring with good rainfall you can get away with planting cereals on these areas, but this is not often, about one in every ten years’.
The impact of advances in technology, and the ability to grow crops on saline soils would have a huge impact according to Andrew. ‘There would be a much better yield potential. Some parts of the farm have gone too far, but more salt tolerant crops would mean that you could probably reintroduce cropping on some parts of the farm that have currently been lost.’
Additional reporting by Steve Criss, Office of Economic Development, University of Connecticut.