biostudies-literatureLiang Gthe NSF Biology Integration Institute ASCEND Advancing Spectral Biology in Changing Environments to understand Diversitythe National Key R&D Program of ChinaNational Key Research and Development Program of Chinathe National Natural Science Foundation of Chinae70193https://www.ebi.ac.uk/biostudies/studies/S-EPMC12018727biostudies-literatureUnknown31(4)Potassium (K) is the second most abundant nutrient element in plants after nitrogen (N), and has been shown to limit aboveground production in some contexts. However, the role of N and phosphorus (P) availability in mediating K limitation in terrestrial production remains poorly understood; and it is unknown whether K also limits belowground carbon (C) stocks, which contain at least three times more C than those aboveground stocks. By synthesizing 779 global paired observations (528, 125, and 126 for aboveground productivity, root biomass, and soil organic C [SOC], respectively), we found that K addition significantly increased aboveground production and SOC by 8% and 5%, respectively, but did not significantly affect root biomass (+9%). Moreover, enhanced N and/or P availability (through Global change biologyAlleviating Nitrogen and Phosphorus Limitation Does Not Amplify Potassium-Induced Increase in Terrestrial Biomass.PMC12018727NSF-DBI-20218982024YFF130900042471122Reich PBLiang GSun PFu ZWaring BGfalseAlleviating Nitrogen and Phosphorus Limitation Does Not Amplify Potassium-Induced Increase in Terrestrial Biomass.Potassium (K) is the second most abundant nutrient element in plants after nitrogen (N), and has been shown to limit aboveground production in some contexts. However, the role of N and phosphorus (P) availability in mediating K limitation in terrestrial production remains poorly understood; and it is unknown whether K also limits belowground carbon (C) stocks, which contain at least three times more C than those aboveground stocks. By synthesizing 779 global paired observations (528, 125, and 126 for aboveground productivity, root biomass, and soil organic C [SOC], respectively), we found that K addition significantly increased aboveground production and SOC by 8% and 5%, respectively, but did not significantly affect root biomass (+9%). Moreover, enhanced N and/or P availability (through 2025-01-01T00:00:00Z2025 Apr2025-07-06T03:04:27.83Z2025-07-06T03:04:27.83ZS-EPMC120187274026947610.1111/gcb.70193