Aligning Nitrogen Form With Rice Preference Through Enhanced-Efficiency Fertilizers Raises Yield and Cuts Emissions.

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Rice cultivation is critical for global food security, feeding nearly half the world's population.
• Low nitrogen (N) use efficiency in rice farming leads to significant environmental degradation and reduced yields.
• Rice primarily absorbs ammonium (NH₄⁺), which is prone to nitrification and loss through water management practices.

Purpose of the Study:

• To evaluate the impact of enhanced-efficiency fertilizers on rice yield and nitrogen use efficiency.
• To quantify the effects of maintaining soil ammonium (NH₄⁺) on greenhouse gas emissions.
• To assess the economic and environmental benefits of N transformation-based management in rice production.

Main Methods:

• Integrated 1756 paired field observations with global modeling.
• Compared enhanced-efficiency fertilizer strategies against conventional practices.
• Quantified changes in rice yield, nitrogen use efficiency, and emissions of ammonia (NH₃), nitrous oxide (N₂O), and methane (CH₄).

Main Results:

• Enhanced-efficiency fertilizers increased rice yield by 6%-10% and nitrogen use efficiency by 18%-33%.
• This management approach reduced ammonia (NH₃) volatilization by 16%-50%, nitrous oxide (N₂O) by 25%-49%, and methane (CH₄) by 9%-30%.
• Potential to reduce global N fertilizer inputs by 1.4 Tg, increase rice production by 72 Tg, and cut CO₂-eq emissions by 202 Tg annually.

Conclusions:

• Aligning nitrogen transformation with rice's nitrogen preference is a pivotal strategy for sustainable agriculture.
• This approach offers substantial economic benefits, valued at US$51 billion, including increased food value.
• The findings highlight a cost-effective method to enhance food security while mitigating climate change impacts.