Abstract: Soil erosion in mountain tea garden becomes serious in Fujian Province, and cultivation at high slope of tea garden causes fertilizer nutrient loss, as well as soil acidification. To find out the impacts of biochar on the changes of soil nutrient leaching of acid red loam soil of tea garden, this study estimated the losses of nutrient in the laboratory by leaching soil column simulation, 5 treatments were set up, including CK(C0N0), 2% biochar with convention fertilizer (C1N1), 5% biochar with convention fertilizer (C2N1), double the amount of fertilizer without biochar (C0N2), regular fertilizing with 2% biochar(C1N1) and regular fertilizing with 5% biochar(C2N1). The results showed that, under conventional fertilization, the volume of leachate decreased significantly with the increase of biochar applied, in addition, TN, NO-3-N and NH+4-N  significantly decreased. The leaching time showed that, the treatments with 2% and 5% biochar detected NO-3-N and NH+4-N later than the treatments without biochar, moreover, the peak of NO-3-N concentrations appeared earlier than NH+4-N. Compared to the treatment with conventional fertilization but without biochar (C0N1), using biochar (C1N1and C2N1) significantly increased soil pH and NO-3-N concentration reduced by 60% and 77%, respectively, NH+4-N concentration reduced by 40% and 39%, respectively. In terms of different nitrogen forms, C1N1和C2N1 detected NO-3-N was earlier than NH+4-N, which indicated the holding capacity of biochar to NH+4-N was better than that of NO-3-N. In conclusion, adding biochar to acid red soil for reducing nitrogen loss and improving soil nutrient content would be significance. These results provided the basis for soil improvement of acid red loam soil in tea garden.

Key words: biochar, acid red loam, tea garden, soil nutrient, nitrate nitrogen, ammonium nitrogen, total nitrogen

摘要： 福建省山地茶园水土流失严重，高坡度开垦茶园会造成土壤养分淋失，引起土壤酸化。为研究生物炭对茶园酸性土壤氮素养分淋溶的影响，采用室内土柱模拟试验，设置对照CK（C0N0）、单施常规量氮肥（C0N1）、单施两倍量氮肥（C0N2）、常规施氮肥增施2%生物炭（C1N1）、常规施氮肥增施5%生物炭（C2N1）5个处理，研究不同生物炭和氮肥添加处理下茶园酸性土壤氮素养分淋溶变化和规律。结果表明，常规施肥条件下，随着生物炭添加量增大，淋滤液体积显著降低，全氮、硝态氮、铵态氮的淋失量显著降低。添加生物炭处理土柱中NO-3-N和NH+4-N的淋溶开始时间均晚于未添加生物炭处理土柱，且NO-3-N的浓度峰值较NH+4-N的出现早。与C0N1相比，生物炭施用处理（C1N1和C2N1）显著提高了土壤pH，NO-3-N的淋溶量分别降低了60%和77%，NH+4-N的淋溶量分别降低了40%和39%。就不同氮素形态而言，C1N1和C2N1处理中均先检测到NO-3-N，说明生物炭对NH+4-N的固持能力大于NO-3-N。研究表明在茶园酸性红壤中添加生物炭可减缓氮素损失，提高土壤养分含量，结果为茶园酸性红壤的土壤改良提供理论依据和参考意义。

关键词: 生物炭, 酸性红壤, 茶园, 土壤养分, 硝态氮, 铵态氮, 全氮