The Soil Is Not Getting The Nitrogen It Needs and That's Very Bad News For The Environment: Study

Plants are a prominent part of the carbon cycle. They help absorb excess carbon dioxide from the atmosphere, and in turn keep the global temperature in check. A recent study published in Nature claims that the carbon fixation capabilities of plants overall have taken a huge hit. It happens because their nitrogen intake has faced a downward spiral. Past investigations have revealed that a healthy content of nitrogen in the soil is vital for the proper absorption of carbon dioxide from the atmosphere by plants. Researchers think that this alteration of circumstances could further weaken the fight against climate change. 

What is the Problem with Nitrogen?

The study's assessment involves readings from 24 scientists spread across the world, as reported by Earth. The objective of the experiment was to remove a suspected bias present in the field measurements of biological nitrogen fixation. Nitrogen fixation is a process performed by microbes to turn nitrogen gas present in the air into a form used by plants. The process occurs in the soil and enhances its fertility.

These measurements primarily hinged on areas where nitrogen-fixing organisms were more in numbers. The accounting of other locations led researchers to understand that the output of nitrogen fixation is way less than what they previously believed. The exercise revealed that the current quantity of biological nitrogen fixation (BNF) is 65 (52–77) Tg N yr−1, which is lower than past estimates. It implies that plants are not getting the nitrogen they need for their life processes.

How does Nitrogen Help Plants?

Plants use nitrogen received through the nitrogen fixation process to formulate protein and chlorophyll. Both of these processes are key for functions, like growth and reproduction, and also crucial in keeping them healthy. Along with these functions, nitrogen is also pivotal in converting atmospheric carbon dioxide into biomass. Less nitrogen for fixation in the soil will have a massive impact on all these operations. Researchers believe the revised numbers indicate that in the next few years, plant growth will slow down, and its capacity to absorb carbon dioxide will also dwindle.

The new readings indicate that the carbon deposit associated with many unmanaged lands in multiple global carbon budgets may need a revisit. These carbon budgets are a plan, whose objective is to figure out how much carbon dioxide can be emitted into the atmosphere before the global climate crosses a threshold temperature. This plan takes into consideration the absorption capability of various resources, like plants, as determined by scientists. Carla Reis Ely, a postdoctoral scholar at Oregon State University College of Forestry, who authored the study, believes past projections made by scientists about the carbon dioxide absorption capability of natural ecosystems need to be revised. 

Contribution of Farmers

Farmers are incorporating nitrogen into the soil by planting legumes, like peanuts, soybeans, alfalfa, and clover. These plants can host nitrogen-fixing bacteria in their roots, which enhances the soil's nitrogen fixation capability. "Using nitrogen-fixing crops in rotation can support long-term soil health and reduce environmental damage from chemical fertilizers," Reis Ely said. However, a good way to tackle the problem of a lack of nitrogen, as an excess of nitrogen fixation is also not good for the environment, experts claimed.

If nitrogen exceeds its required amount, it could run off into lakes, streams, and groundwater, damaging water quality. The extra nitrogen could also turn into nitrous oxide, a greenhouse gas, and enter the atmosphere. "High agricultural nitrogen fixation is a complex issue. We do benefit from it, but along with applications of synthetic nitrogen fertilizer, it contributes to nitrogen pollution and climate change," shared Reis Ely. "Measuring and monitoring biological nitrogen fixation needs to be ongoing to help us ensure we have all the nitrogen in the ground that we need without it becoming too much of a good thing."