Using Salt Water Irrigation to Grow Crops in Salty Soil: Expanding Cropland

Some species of Panicum grasses are quite tolerant to salt, and can be grown on salty soil to provide animal feed. Even more surprisingly, some strains of these species of Panicum can be irrigated with salt water, minimally fertilised, and grow healthy harvests!

The research team focused on a plant called Panicum turgidum that can grow in salty conditions. They measured its protein content and determined that it could be a suitable alternative to existing cattle feed.

Then they tested its growth potential when irrigated with the salty water found in the area. They showed that Panicum grew so fast it could be harvested almost monthly. Overall, with limited fertilizer, they produced 60,000 kilograms per hectare during the yearlong study. Nielsen is confident that further studies that determine the best ratios of fertilizer will boost that number over 100,000 kilograms.

The researchers also used nature to preserve a sustainable growing environment. Panicum is a "salt excluder," meaning it survives salty conditions by keeping salt out of its system, which most other plants can't do.

Although this allows Panicum to grow on salty water, the extra salt deposited by irrigation would render the soil too salty for even this hardy plant. So the researchers found that planting a companion crop that is a "salt accumulator" prevented the soil from getting too salty.

The other plant sucked up the extra salt, then was harvested and burned and the ashes turned into soap. After the yearlong study, the levels of salt in the soil were virtually unchanged. _SeedDaily

By growing large amounts of animal feed on salty soil not suitable for growing human foods, huge areas of arable cropland can be freed up for food and/or cash crops -- rather than devoting much of it to growing maize for animals.

Of course salt-tolerant plants can also be used as biomass for pyrolysis, gasification, torrefaction, etc.

The most fascinating breakthroughs will occur when the genes that allow salt tolerance, salt-rejection, and salt-concentration, can be selectively inserted (along with any necessary helper genes and epigenetic apparatus) into plants or microbes of one's choosing.