Affiliations: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
Abstract: The effects of two lignins isolated from black liquor from pulping process on nitrification in soils after addition of urea, (NH_{4})_{2}SO_{4} and (NH_{4})_{2}HPO_{4} were investigated by incubation at 20 or 30°C for 7 or 14 d. The effects of lignin on nitrous oxide emissions from soil were also determined. Results showed that both lignins were more effective for inhibiting nitrification of NH_{4}^{+}-N as (NH_{4})_{2}SO_{4} or (NH_{4})_{2}HPO_{4} as compared to urea-N. The effectiveness of lignin on nitrification was markedly affected by different soil type and temperature. Nitrous oxide emissions from soil declined when lignin was used. Urea plus 20 and 50 g/kg lignin reduced N_{2}O emissions by about 83% and 96%, respectively, while (NH_{4})_{2}HPO_{4} plus 20 and 50 g/kg lignin respectively reduced emissions by 83% and 93%. Because of its low cost and nonhazardous characteristics, lignin has potential value as a fertilizer amendment to improve N fertilizer efficiency.