生物炭与氮肥配施对烤烟干物质积累及土壤生物学特性的影响

Effects of biochar and nitrogen fertilizers on dry matter accumulation of flue-cured tobacco and soil biological characteristics

为探讨生物炭与氮肥配施对烤烟生长及植烟土壤生物学特性的影响,通过田间试验,研究了生物炭与氮肥配施对烤烟不同生育阶段干物质积累、土壤酶活性、微生物量碳(MBC)、有机碳含量的影响。结果表明:N_1(22.5 kg·hm^(-2))、N_2(37.5 kg·hm^(-2))和N_3水平(52.5 kg·hm^(-2))下,增施2.4 t·hm^(-2)生物炭显著提高了烤烟生育中后期的干物质积累量和烟株移栽后90 d的氮肥利用率,且氮肥利用率以低氮(N1)水平下提高效果最明显。3个氮水平下,施用生物炭对转化酶活性整体表现为抑制作用;N_1和N_2水平下,增施生物炭可分别显著增加脲酶和过氧化氢酶活性。此外,在N_1和N_2水平下,增施2.4 t·hm^(-2)生物炭还显著提高了烤烟生育后期的MBC含量。生物炭与氮肥配施还显著提高了烤烟全生育期的土壤有机碳含量。总之,生物炭与氮肥配施可以改善土壤生物学性状,促进烤烟生长,且以低氮水平下增施2.4 t·hm^(-2)生物炭效果较好。

Changes of dry matter accumulation,enzymatic activity of flue-cured tobacco,microbial biomass carbon（ MBC） and soil organic carbon were studied at different growth stages to explore the effects of biochar and nitrogen fertilizer on tobacco growth and soil biological characteristics via a field experiment. It was shown that at N1（ 22. 5 kg·hm^-2）,N2（ 37. 5 kg·hm^-2） and N3levels（ 52. 5 kg·hm^-2）,application of 2. 4 t·hm^-2biochar remarkably improved dry matter accumulation in the middle and late growth stage of flue-cured tobacco and utilization rate of nitrogen fertilizer after 90 d of transplanting,and the nitrogen utilization efficiency increased the most at low nitrogen level（ N1）. For all 3 N levels,application of biochar restrained sucrase activity. Meanwhile,for N1 and N2levels,application of biochar could significantly increase urease and catalase activity. Besides,application of 2. 4 t·hm^-2biochar significantly increased MBC content in the late growth stage of flue-cured tobacco at N1 and N2levels. Application ofbiochar with nitrogen fertilizers could remarkably increase soil organic carbon content during the whole growth period of flue-cured tobacco. In general,application of biochar and nitrogen fertilizer could improve soil biological characteristics and promote the growth of flue-cured tobacco,and at a low nitrogen level,application of 2. 4 t·hm^-2biochar exhibited a better effect.