Compost Quality and Application Rate as Drivers of Soil Health, Nutrient Cycling, and Crop Performance: A Critical Review and Practical Rate-Design Framework
- 1Colorado State University Extension, Fort Collins, CO 80253, USA
Abstract
Compost offers high potential for sustainable agriculture, but its agronomic outcomes vary. This critical review combines qualitative evidence with literature-derived quantitative benchmarks for compost maturity, salinity, nutrient loading, application-rate classes and monitoring triggers. Evidence demonstrates that mature, stable composts consistently improve soil health, including aggregation, water-holding capacity, soil organic carbon (SOC), and nutrient availability while boosting crop yield and establishment. These high-quality composts are characterized by low phytotoxicity, moderate C:N ratios, acceptable EC levels, and pathogen compliance. However, benefits are not universal. Immature or poorly stabilized compost poses risks of phytotoxicity, ammonia toxicity, and nitrogen immobilization. Excessive application rates are associated with nutrient imbalances, increased salinity, nitrate leaching, phosphorus runoff, greenhouse-gas trade-offs, and cumulative contaminant loading. To enhance the precision of rate recommendations, this review categorizes applications into four distinct tiers: starter or maintenance (2–5 Mg dry matter ha−1), common agronomic (5–20 Mg ha−1), rehabilitation (20–35 Mg ha−1), and high-risk (>35 Mg ha−1). It posits that the final application rate must be dictated by the most limiting factors, such as crop nitrogen requirements, soil-test phosphorus levels, salinity tolerance, contaminant thresholds, hydrologic risk, or specific management objectives. In conclusion, while manure-based composts enhance short-term fertility, they introduce significant risks of phosphorus accumulation and salinity compared to green-waste alternatives. This review, therefore, redefines compost not as a generic organic amendment, but as a quality-controlled, rate-sensitive input essential for precision nutrient management.
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BibTeX
@article{manono2026compost,
title = {{Compost Quality and Application Rate as Drivers of Soil Health, Nutrient Cycling, and Crop Performance: A Critical Review and Practical Rate-Design Framework}},
author = {Bonface Ombasa Manono},
journal = {Nitrogen},
year = {2026},
month = may,
doi = {10.3390/nitrogen7020058},
url = {https://doi.org/10.3390/nitrogen7020058},
note = {CC BY},
}
RIS
TY - JOUR
TI - Compost Quality and Application Rate as Drivers of Soil Health, Nutrient Cycling, and Crop Performance: A Critical Review and Practical Rate-Design Framework
AU - Bonface Ombasa Manono
PY - 2026
DA - 2026/05/31
JO - Nitrogen
DO - 10.3390/nitrogen7020058
UR - https://doi.org/10.3390/nitrogen7020058
AB - Compost offers high potential for sustainable agriculture, but its agronomic outcomes vary. This critical review combines qualitative evidence with literature-derived quantitative benchmarks for compost maturity, salinity, nutrient loading, application-rate classes and monitoring triggers. Evidence demonstrates that mature, stable composts consistently improve soil health, including aggregation, water-holding capacity, soil organic carbon (SOC), and nutrient availability while boosting crop yield and establishment. These high-quality composts are characterized by low phytotoxicity, moderate C:N ratios, acceptable EC levels, and pathogen compliance. However, benefits are not universal. Immature or poorly stabilized compost poses risks of phytotoxicity, ammonia toxicity, and nitrogen immobilization. Excessive application rates are associated with nutrient imbalances, increased salinity, nitrate leaching, phosphorus runoff, greenhouse-gas trade-offs, and cumulative contaminant loading. To enhance the precision of rate recommendations, this review categorizes applications into four distinct tiers: starter or maintenance (2–5 Mg dry matter ha−1), common agronomic (5–20 Mg ha−1), rehabilitation (20–35 Mg ha−1), and high-risk (>35 Mg ha−1). It posits that the final application rate must be dictated by the most limiting factors, such as crop nitrogen requirements, soil-test phosphorus levels, salinity tolerance, contaminant thresholds, hydrologic risk, or specific management objectives. In conclusion, while manure-based composts enhance short-term fertility, they introduce significant risks of phosphorus accumulation and salinity compared to green-waste alternatives. This review, therefore, redefines compost not as a generic organic amendment, but as a quality-controlled, rate-sensitive input essential for precision nutrient management.
SN - 2504-3129
ER -