Science

Tree microbes could help crops draw phosphorous from fertilized soil

Tree microbes could help crops...
The endophyte bacteria used in the study were gathered from wild poplar trees growing along the Snoqualmie River in Western Washington
The endophyte bacteria used in the study were gathered from wild poplar trees growing along the Snoqualmie River in Western Washington
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The endophyte bacteria used in the study were gathered from wild poplar trees growing along the Snoqualmie River in Western Washington
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The endophyte bacteria used in the study were gathered from wild poplar trees growing along the Snoqualmie River in Western Washington

Agricultural fertilizers typically contain phosphorous, as it's essential to growing plants. Unfortunately, though, it can become "locked" in the soil, and thus not available to crops. That said, it turns out that the addition of a microbe could unlock it.

When applied to crops as part of a fertilizer, phosphorous often reacts with minerals already in the soil, forming chemical complexes with them. These complexes can't be taken up by the plants' roots, so the phosphorous simply remains in the dirt.

In order to compensate for the problem, farmers will often apply excessive amounts of fertilizer to the fields. Not only is this expensive, but much of that fertilizer ends up running off into surrounding waterways, polluting them.

Led by Prof. Sharon Doty, scientists at the University of Washington previously discovered that root-dwelling microorganisms known as endophytes allow wild-growing trees to pull phosphorous from the soil. This is true even of trees growing in rocky soil alongside clear mountain-fed streams, where nutrients are in short supply.

In a more recent study – conducted in collaboration with the Pacific Northwest National Laboratory – the researchers gathered endophytes from the roots of wild poplar trees, and added them to soil in which phosphorous was locked within chemical complexes.

It was found that the microbes broke apart those complexes, making the phosphorous available to poplar seedlings that had been planted in the dirt. Further testing confirmed that the phosphorous had indeed been taken up by the plants, through their roots.

The scientists now hope that commercially grown endophytes could be mixed with the soil amongst young plants, or even used to coat seeds prior to planting. Not only could the microorganisms then keep freshly-applied phosphorous available to the crops, but they could also free up phosphorous that was already locked in the soil from previous growing seasons.

The endophyte strains used in the study have been licensed to California-based company Intrinsyx Bio, with an eye toward commercialization.

A paper on the research was recently published in the journal Frontiers in Plant Science.

Source: University of Washington

2 comments
Kevon Lindenberg
It's about time we figured out a solution to this problem.
Karmudjun
I just love it when research scientists tackle a topic known by farmers who practice organic farming - and prove that there is a "Scientific" reason for the organic farmers approach to repleting their soils. The microbes in animal dung spread across your fields 'somehow' improved the soil, the use of vermiculture - or the presence of increased earthworm activity - was one sign you had "brought your soil back to health". Good to know that organic farmers can start checking for "endophytes" as well as looking at the way the soil turns, and the plants grow. Great job University of Washington Researchers! Please solve the chestnut blight, the Elm tree blight, and get rid of those murder hornets for us. My farming cousins haven't been able to solve those issues while their organic farming practices have solved much of their fertilizer issues.