LAUSR

ABSTRACT Excessive application of nitrogen (N) fertilizer has acidified soils to pH levels below the optimum, posing a threat to tea plant cultivation. Organic livestock manure rich in alkaline substances can counteract the H+ produced by soil nitrification of N fertilizer. However, how ameliorating acidification using livestock manure affects nitrification and greenhouse gas nitrous oxide (N2O) emissions in tea-planted soils remains unclear. Here, by adding four types of manure (cow, sheep, chicken, and pig) at rates of 0, 100, and 200 mg N kg−1 into a tea-planted soil, we showed that all manure additions alleviated soil acidification and increased net N mineralization and nitrification significantly, with the increases becoming more pronounced with increasing rate. While soil cumulative N2O emissions were enhanced significantly by sheep, chicken, and pig manure and reduced significantly by cow manure at the high rate, with opposite trends at the low rate. Net nitrification and cumulative N2O emissions were significantly and negatively correlated with carbon (C)/N of added manure at both rates and at the high rate alone, respectively. Our findings highlight the importance of selecting the appropriate livestock manure (i.e. high C/N) to alleviate soil acidification while minimizing nitrification and N2O emissions.