The response of soil organic carbon to nitrogen-induced multiple ecological attributes

Abstract

Increasing concentrations of CO2 and reactive nitrogen (N) in the earth’s atmosphere are seriously threatening the human well-being. Globally, the response of SOC to the N application is inconclusive. Study reports the responses of SOCs to N application, species diversity (D), root primary productivity (RP), temporal stability of RP, soil-pH and soil-Al. Within experimental grassland at Varanasi, India, 72 1 × 1 m plots with 6N-input levels, and with 12 replicates, were established in 2013. For 3 years, different doses of urea as a source of N were applied to the plots. Data on above soil and vegetation variables were recorded and statistically analysed. The D, RP, TS, soil-pH, soil-Al and SOC significantly differed due to N application. Except the TS, each studied variable individually governed the SOC. The N fertilization modulated D, RP and soil-Al synergistically determined the SOC of the tropical grasslands. Below the 104–110 kg N-dose, the SOC showed positive response while above to this dose, it negatively responded. Thus, N application to the tropical grassland should not exceed 104–110 kg N; otherwise, N-induced ecological effects would be harmful to the sustainability of human well-being. © 2020, Springer Nature B.V.