19 May 2021

Double-edged nitrogen is one more reason for a sustainable agriculture


Nitrogen is essential but watch out for its negative potential says a study from the University of Melbourne. The solutions? Responsible agricultural techniques and economic incentives for companies and citizens

by Matteo Cavallito


Nitrogen is a precious and essential element for crops. But it’ also dangerous for the environment. In fact, “it is also a leading cause of pollution across the world.” That is why its use in agriculture must be supported by sustainable solutions with the aim of balancing both positive and harmful effects according to a study led by Xia Liang, member of the American Society of Agronomy and agricultural researcher at the University of Melbourne. The survey provides a picture that accurately measures nitrogen loss in a wide variety of crops and food products. This trend is also linked to the massive use of nitrogen-based fertilizers.

By identifying the environmental impacts and social costs of these losses, Liang says, we can “to potentially provide information to inform consumers, producers, and policymakers.” With the goal of making agricultural systems around the world more sustainable, less polluting and more profitable.

Nitrogen: looking for the right balance

In order to assess the size of the problem, two different aspects must be considered: the overall loss and the relative data, i.e. the intensity, calculated as the loss per unit of food or nitrogen produced. “For example, cereal grains have a low loss intensity but a high overall loss because they are grown in such large quantities. On the other hand, an animal product like buffalo meat has a high loss intensity but a low overall loss. This is due to the small amount produced.”

The survey led to the construction of a database that includes 115 agricultural and 11 livestock products on a global scale. Livestock – from beef (which has the highest loss intensity) to lamb, pork and others – tops the list for contribution to nitrogen pollution ahed of rice, wheat, corn, pork and soybeans. “The lowest nitrogen loss for the 11 livestock products exceeds that of vegetable substitutes,” Liang says. “This confirms the importance of dietary change to reduce nitrogen loss through consumption.”

Smog and climate effects are both alarming

The focus on the negative effects of nitrogen leakage is clearly mounting in recent years. It is therefore not surprising that the European Commission is developing incentive schemes for sustainable agricultural practices that can take into account the entire balance of greenhouse gases. Which means including not only CO2 but also methane and nitrous oxide. The damages of the loss, however, are well known. These include the impact on soil and water damages, the harmful effects on plants and animals and the contribution to smog and climate change.

The available solutions, the research shows, are complex and ” include better fertilizer technologies and practices, improved crop varieties, and following the 4 Rs: using the right fertilizer in the right amount at the right time in the right place.”

Consumers must also do something

To ensure a satisfactory result, in any case, it is necessary to provide incentives for best management practices that include “reducing the risk of soil degradation and erosion and the overuse of fertilizers.” Finally, individual behaviors are also crucial. Consumer, for example, may decide to decrease meat consumption and food waste. However, it would seem that there is still a long way to go. “When we buy a washing machine or a car, we can choose a more water efficient and energy efficient product by water and energy rating,” Liang says. “However, despite growing recognition of the importance of nitrogen in sustainable food production and consumption, we don’t follow a similar idea for foods we eat.”