Nitrogen-centered nutrient innovation for decoupling agricultural productivity from greenhouse-gas intensity: evidence, limits, and implementation pathways
Year: 2026
Type: article
Abstract: Increasing agricultural production while lowering greenhouse-gas (GHG) intensity is a defining challenge for climate-smart agrifood systems. This critical review evaluates nitrogen-centered nutrient innovations through a boundary-explicit, two-axis framework: evidence confidence for a stated productivity-GHG decoupling outcome and implementation readiness in a specified context. The synthesis covers enhanced-efficiency fertilizers (EEFs), biological nitrogen fixation (BNF), biological nitrification inhibition (BNI), site-specific nutrient management (SSNM), 4R stewardship, precision placement, digital decision support, circular nitrogen recovery, and integrated nutrient management (INM). Direct evidence requires paired crop-output and GHG data; nitrogen-use efficiency, fertilizer savings, nutrient-loss reduction, or soil-quality responses alone are classified as partial or supporting evidence. Evidence confidence is highest for locally calibrated SSNM, 4R rate-timing-placement practices, and selected EEFs in high-surplus or high-loss systems, although performance varies with crop, soil, climate, baseline nitrogen rate, and the measured boundary. Implementation readiness is high for established stewardship practices, moderate and context-dependent for EEFs, digital tools, recovered products, and BNI, and low for many nanofertilizers and non-legume microbial inoculants. Circular products may provide life-cycle benefits, but results depend on allocation, substitution, transport, energy, indirect N 2 O, and avoided-waste assumptions. Short-term biogenic soil CO 2 flux is not treated as fossil climate forcing; soil-carbon benefits require stock-change measurements with defined depth, baseline, duration, and permanence. Evidence is concentrated in cereal and high-input systems, and publication, language, citation-selection, and outcome-reporting biases limit generalization. Reliable decoupling therefore requires integrated portfolios, transparent accounting, independent field validation, and performance-oriented policy rather than claims based on input reduction alone.
Author: Bonface Ombasa Manono
Language: English
Subfield: Soil Science
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,353
OpenAlex ID: W7214627055