he results also indicate that using compost on land can provide marginal savings to global warming (−1.7 PE), acidification (−0.8 PE), and ecotoxicity and human toxicity via water and soil. The substitution of this compost for commercial N, P, and K fertilizers would thus avoid environmental impacts of fertilizer production. For example, the substitution of compost for a P fertilizer would avoid nutrient enrichment, ecotoxicity in water, and human toxicity via water, with normalization impacts of −11.1 PE, −2.5 PE, and −8.2 PE, respectively. The normalization impacts of using compost on farmland are shown in Fig. 4. Due to the N loss in soil, using compost causes incremental nutrient enrichment as neutralization of emissions (27.6 PE) and substitution (−12.8 PE). According to the investigation on life cycle inventory, NO3− emission into surface water contributes most to nutrient enrichment (26.9 PE). Therefore, the chemical speciation and loss of N in the compost should be controlled carefully during composting and use.