Integrative knowledge-based nitrogen management practices can provide positive effects on ecosystem nitrogen...

Area of Science:

• Agricultural Science
• Environmental Science
• Soil Science

Background:

• Knowledge-based nitrogen (N) management aims to synchronize crop N demand with supply for improved production and reduced N losses.
• Global impacts of specific N management practices on ecosystem N cycling remain unclear.

Purpose of the Study:

• To assess the global impacts of four common knowledge-based N management practices on ecosystem N cycling.
• To evaluate how balanced fertilization, organic fertilization, co-application of fertilizers, and nitrification inhibitors affect N retention and loss.

Main Methods:

• Compiled 5,448 paired observations from 336 publications across 286 sites.
• Analyzed data to determine the effects of different N management strategies on soil N dynamics.

Main Results:

• Organic and balanced fertilization enhanced soil nitrate retention via microbial biomass but increased N leaching and emissions compared to unfertilized controls.
• N-only fertilization showed less benefit than organic or balanced approaches.
• Nitrification inhibitors improved soil ammonium retention and plant N uptake, significantly reducing N leaching and emissions.

Conclusions:

• Integrative application of knowledge-based N management practices is crucial for enhancing ecosystem N retention.
• Nitrification inhibitors show significant promise for minimizing N loss risks globally.
• Optimizing N management requires a nuanced approach, considering the specific impacts of different practices.