Wheat can itself retain the fertilizer and reduce nitrogen emissions.

Økologisk Nu
Wheat can itself retain the fertilizer and reduce nitrogen emissions.

Wheat is not just one of the world's most important crops. It is also much more cunning than most people think. New research from Aarhus University shows that wheat plants actively help themselves retain nitrogen, one of agriculture's most important and problematic nutrients. They do this with chemistry. The university states this in a press release. Underground, the roots naturally release substances that inhibit microorganisms that would otherwise convert nitrogen into forms that easily disappear from the soil. The result is simple: more nitrogen remains in the soil and less is lost to the environment. A major problem in modern agriculture Nitrogen is essential for crop growth. But the system is inefficient. Today, plants absorb less than half of the fertilizer applied to fields. The rest is lost: - as leaching into water bodies - or as nitrous oxide, a potent greenhouse gas For decades, agriculture has tried to find solutions. One option has been chemical nitrification inhibitors. They can slow nitrogen loss but are expensive, need to be applied repeatedly, and can affect soil life. But what if the plants could do the work themselves? This is precisely what researchers have now gained better insight into. The phenomenon is called biological nitrification inhibition (BNI), and it refers to plants' ability to regulate nitrogen in the soil themselves. “Plants are not passive,” explains postdoc Purna Kumar Khatri from the Department of Agroecology at Aarhus University. “They actively fight for nutrients. And they have much more advanced strategies than we have long been aware of.” A chemical language in the soil At the center are a group of natural substances called benzoxazinoids. They are found in grains like wheat, maize, and rye and have long been known to protect plants from pests and weeds. Now, research shows that several of them also inhibit bacteria responsible for nitrification: the process where nitrogen becomes more volatile and easier to lost. In other words: the plant actively influences its own soil. In the experiment, researchers compared different types of wheat. Some had a particular genetic trait that made them better at releasing these active substances from their roots. The result was clear: these wheat lines could significantly inhibit nitrification. Other studies suggest that such traits could reduce nitrogen loss by up to 20–30%. At the same time, initial field trials indicate that this does not affect yields. “If we can just increase nitrogen use efficiency by about ten percent in practice, it will have enormous effects both economically and environmentally,” says Purna Kumar Khatri. A solution that grows in the field One advantage of the plants' own mechanism is precision. Where chemical agents are added in large doses, the plant releases small amounts exactly where the roots grow. This makes the solution both more targeted and potentially gentler on the soil ecosystem. The researchers are now working to translate this chemical knowledge into plant breeding. The goal is to develop wheat varieties that are even better at retaining nitrogen themselves. If successful, future crops could: - require less fertilizer - reduce climate impact - and simultaneously ensure stable yields “This is where chemistry meets genetics,” says Purna Kumar Khatri, adding: “When we understand the mechanisms, we can also start to improve them.”

Wheat is not just one of the world's most important crops. It is also far more cunning than most people think.

New research from Aarhus University shows that wheat plants actively help themselves retain nitrogen, one of agriculture's most important and problematic nutrients.

They do this with chemistry. This is stated by the university in a press release.

Underground, the roots naturally release substances that inhibit the microorganisms that otherwise convert nitrogen into forms that easily disappear from the soil.

The result is simple: More nitrogen remains in the soil and less is lost to the environment.

A major problem in modern agriculture

Nitrogen is essential for crop growth. But the system is inefficient. Today, plants absorb less than half of the fertilizer applied to the fields. The rest disappears:

For decades, agriculture has tried to find solutions. One option has been chemical nitrification inhibitors. They can slow nitrogen loss, but they are expensive, need to be used repeatedly, and can affect soil life. But what if the plants themselves could do the work?

This is exactly what researchers have now gained better insight into.

The phenomenon is called biological nitrification inhibition (BNI), and it encompasses plants' ability to regulate nitrogen in the soil themselves.

“Plants are not passive,” explains postdoc Purna Kumar Khatri from the Department of Agroecology at Aarhus University.

“They actively fight for nutrients. And they have much more advanced strategies than we have long been aware of.”

A chemical language in the soil

At the center is a group of natural substances with the somewhat technical name benzoxazinoids. They are found in grains like wheat, maize, and rye and have long been known to protect plants against pests and weeds.

Now, research shows that several of them also inhibit bacteria responsible for nitrification: the process where nitrogen becomes more volatile and easier to lost. In other words: the plant actively influences its own soil.

In the experiment, researchers compared different types of wheat. Some had a special genetic trait that makes them better at secreting these active substances from the roots.

The result was clear: these wheat lines could significantly inhibit nitrification.

Other studies suggest that such traits can reduce nitrogen loss by up to 20–30 percent. At the same time, initial field trials indicate that this does not affect yields.

“If we can just increase nitrogen use efficiency by about ten percent in practice, it will have enormous effects both economically and environmentally,” says Purna Kumar Khatri.

A solution that grows in the field

One of the advantages of the plants' own mechanism is precision.

While chemical agents are added in large doses, the plant itself releases small amounts exactly where the roots grow. This makes the solution both more targeted and potentially gentler on the soil ecosystem.

The researchers are now working on translating this chemical knowledge into plant breeding. The goal is to develop wheat varieties that are even better at retaining nitrogen themselves.

If successful, future crops could:

“This is where chemistry meets genetics,” says Purna Kumar Khatri, and adds:

“When we understand the mechanisms, we can also start to improve them.”