小麦生物质炭对烤烟生长及根际土壤理化性质的影响

Effects of biochar amendment on flue-cured tobacco growth and soil physical and chemical properties of rhizosphere

【目的】探讨生物质炭对烤烟前期生长、根际土壤理化性质及酶活性的影响。【方法】以烤烟K326为供试品种,采用盆栽试验,研究不同用量(0%(对照),0.1%,0.5%,1%,2%,3%)小麦生物质炭施入后对烤烟前期农艺性状、根际土壤理化性质及酶活性的影响。【结果】与对照相比,不同用量的生物质炭对还苗期烟草叶片数、株高、叶绿素含量无显著影响,但是总体上增加了最大叶面积,其中生物质炭用量为3%的处理使烤烟的最大叶面积较对照显著增加了155.3%。不同用量生物质炭总体上增加了团棵期烟草的叶片数、最大叶面积和叶绿素含量,但株高与对照相比无显著变化,当生物质炭用量为3%时,最大叶面积、叶片数分别较对照显著增加17.7%和21.5%。与对照相比,不同用量生物质炭影响了烟草团棵期地上部生物量,但对地下部生物量无显著影响。生物质炭的施用影响烟草根际土壤的理化性质,其中生物质炭用量为3%的处理,烟草根际土壤的有机碳、全氮、全钾、速效磷、速效钾含量较对照分别显著提高了302.3%,41.7%,114.0%,220.3%和474.8%,pH提高了0.50,而对土壤全磷含量没有显著影响。与对照相比,生物质炭用量为2%的处理,烟草根际土壤脲酶活性增加了35%;而生物质炭用量为0.5%和3%的处理,土壤蔗糖酶活性分别增加了108%和100%;但是生物质炭的施用却降低了土壤脱氢酶的活性,生物质炭用量为0.5%,1%,2%和3%的处理,土壤脱氢酶活性分别较对照降低了51.5%,63.6%,63.6%和51.5%。相关性分析表明,烟叶地上部干质量与土壤有机碳、氮含量和蔗糖酶活性呈显著正相关关系(P<0.05),与速效钾含量呈极显著正相关关系(P<0.01),而与脱氢酶活性呈极显著负相关关系(P<0.01)。【结论】施用生物质炭不仅可改善烟叶的农艺性状,而且会影响土壤理化性质和酶活性,其中以生物质炭用量为3%时效果较佳。

【Objective】This study investigated the effects of biochar amendment on growth of fluecured tobacco,soil physical and chemical properties and soil enzyme activities.【Method】Agronomic traits,soil physical and chemical properties and enzyme activities of flue-cured tobacco K326 were studied under pot experiment with different application rates of biochar（0%（control）,0.1%,0.5%,1%,2%,and 3%）.【Result】As compared to the control,different biochar amendments had no significant effect on leaf num-ber,plant height and chlorophyll content of tobacco at seedling stage,but increased maximum leaf area.The maximum leaf area of flue-cured tobacco was significantly increased by 155.3% compared with the control under 3% biochar amendment.Different biochar amendments increased leaf number,maximum leaf area and chlorophyll content at the glomeration stage,but had no effect on plant height.The maximum leaf area and leaf number were increased significantly by 17.7%and 21.5% under 3% biochar amendment,respectively.Different biochar amendments affected aboveground biomass,but had no significant effect on underground biomass at the glomeration stage.The application of biochar affected physical and chemical properties of tobacco rhizosphere soil.The contents of organic carbon,total nitrogen,total potassium,available phosphorus,available potassium and soil pH in rhizosphere soil were increased by 302.3%,41.7%,114.0%,220.3%,474.8% and 0.50 under 3% biochar amendment,respectively,but soil total phosphorus content was not affected.Compared with the control,soil urease activity was increased by 35%in rhizosphere soil under 2% biochar amendment.The activity of soil sucrase was increased by 108% and 100% under 0.5%and 3% biochar amendment,respectively.However,soil dehydrogenase activity was decreased by 51.5%,63.6%,63.6% and 51.5% under 0.5%,1%,2% and 3% biochar amendment,respectively.Shoot dry weight had significant and positive correlations with soil total carbon,nitrogen and soil invertase activity（P〈0.05）,very significant and positive correlation with available potassium（P〈0.01）,and significant and negative correlation with soil dehydrogenase activity（P〈0.01）.【Conclusion】Biochar not only improved agronomic traits of tobacco leaves,but also affected soil physical and chemical properties and enzyme activities.The 3% biochar application was the best for improving soil function and tobacco growth.