Agriculture has always been a double-edged sword when it comes to the environment. While it feeds billions, it also contributes significantly to greenhouse gas emissions and nitrogen pollution. Nitrogen fertilizers, critical for plant growth, often escape into the atmosphere as nitrous oxide—a greenhouse gas nearly 300 times more potent than CO2—or into waterways as nitrates, causing water pollution and dead zones.

But a team of researchers at Texas A&M AgriLife may have found a groundbreaking solution that could change the game for farmers and the planet. Led by Dr. Nithya Rajan, the team is working on sorghum varieties that possess a trait known as biological nitrification inhibition (BNI). This trait could dramatically reduce nitrogen loss from croplands, making farming both more efficient and environmentally friendly.

What Is Biological Nitrification Inhibition?

When farmers apply nitrogen fertilizers, they face a major problem: much of the nitrogen doesn’t stay in the soil long enough to benefit the crops. Instead, it undergoes a process called nitrification, where soil bacteria convert the fertilizer-derived ammonium into nitrate. This nitrate is easily lost—either leaching into water systems or being released into the atmosphere as nitrous oxide, a potent greenhouse gas.

Pic Credit: Dr Nithya Rajan

Some plants, however, naturally inhibit this process by releasing biological nitrification inhibitors from their roots. This BNI trait keeps nitrogen in the form of ammonium, preventing it from being converted to nitrate. Dr. Rajan and her team have been investigating this trait in sorghum, a crop grown widely across the world for grain, forage, and even bioenergy.

After three years of field testing, the results are promising: sorghum with the BNI trait significantly reduces nitrogen loss, keeping it in the soil where it can be used by the plants. This not only lowers the cost for farmers—by reducing the need for additional fertilizer—but also cuts down on harmful nitrous oxide emissions.

A Breakthrough in Nitrogen Use Efficiency

The nitrogen use efficiency (NUE) of crops has long been a focus of agricultural research. Most traditional farming practices result in low NUE, meaning that a significant portion of applied fertilizers never reaches the plants. This inefficiency not only hurts the farmer’s bottom line but also has far-reaching environmental consequences.

In today’s farming, nitrogen fertilizers are often combined with nitrification inhibitors—chemicals that slow down the nitrification process. However, these inhibitors add extra costs and chemicals to the farming process. The BNI trait in sorghum offers a natural alternative, allowing farmers to grow crops with improved nitrogen retention in the soil, potentially eliminating the need for synthetic nitrification inhibitors.

Dr. Rajan explains, “The BNI trait will suppress nitrification, a microbial process that converts fertilizer-derived ammonium in the soil to nitrate, and not allow it to escape as nitrates in water or nitrous oxide as a greenhouse gas.”

Minimal Impact on Soil Health

Another critical aspect of this research is its effect on soil microbiomes. Concerns about how altering the nitrification process could affect soil health were addressed by Sanjay Antony-Babu, a soil microbiologist at AgriLife Research. His work shows that the BNI trait selectively targets nitrifying bacteria, responsible for nitrogen loss, while leaving the broader soil microbiome—essential for crop and soil health—largely intact.

This ensures that while nitrogen retention improves, the diversity of beneficial soil organisms remains healthy, promoting long-term soil sustainability.

Bioenergy Sorghum: A New Frontier

The implications of this research extend beyond traditional farming. One exciting avenue being explored is the integration of the BNI trait into bioenergy sorghum. Unlike grain sorghum, bioenergy sorghum is grown specifically for its large biomass, which can be used to produce renewable biofuels.

Bioenergy sorghum is designed to grow for longer periods and doesn’t produce grain, which allows it to be more drought-tolerant and efficient in producing cellulosic biomass. Incorporating the BNI trait into this crop could make bioenergy sorghum even more climate-friendly by reducing its need for nitrogen fertilizers while increasing nitrogen-use efficiency.

The Future of Climate-Smart Crops

The ultimate goal of this research is to develop a climate-smart sorghum that not only reduces input costs but also contributes to the global fight against climate change. By keeping more nitrogen in the soil and out of the atmosphere, BNI sorghum could help reduce agriculture’s overall greenhouse gas emissions.

Additionally, as governments around the world begin to recognize the importance of sustainable farming practices, crops like this could be eligible for carbon credits, giving farmers further incentives to adopt them.

“Nitrogen is essential to producing food, but its use can also cause issues,” Rajan said. “Developing climate-smart crop varieties is an excellent solution as it can prevent substantial nitrogen escape through water or as a greenhouse gas.”

Also Read: What Are The Three Principles Of Climate Smart Agriculture?

Conclusion: A Win for Farmers and the Planet

The work being done at Texas A&M AgriLife is a crucial step toward making agriculture more sustainable. By harnessing the BNI trait in sorghum, farmers can reduce their dependence on costly fertilizers while also playing a role in reducing greenhouse gas emissions. This is the kind of innovation that has the potential to reshape how we think about farming in a warming world.

As the research team continues to refine the BNI trait and expand its use into other crops, we could be on the brink of a new era in agriculture—one where economic and environmental goals go hand in hand.

Also Read: The Future Of Agriculture: Sustainable Solutions For Feeding A Growing Population