深耕条件下生物炭对烤烟根系活力、叶片SPAD值及土壤微生物数量的动态影响

Dynamic Effects of Biochar on Root Vigor,Leaf SPAD Value and Soil Microbial Quantity of Flue-Cured Tobacco under Deep Tillage Condition

为探讨深耕条件下有利于湘西自治州土壤微生态环境和烤烟生长的施炭量。以云烟87为试验材料,在深耕深度均为30 cm的条件下,设置了生物炭用量分别为3 000 kg/hm^2(T1)、3 750 kg/hm^2(T2)与4 500 kg/hm^2(T3)的3个处理和不施用生物炭的对照(CK),研究了深耕条件下施用生物炭后,各处理烤烟在3个生育时期的根系活力、叶片SPAD值及土壤微生物数量的动态变化。结果表明:(1)在深耕条件下施用生物炭能促进烤烟根系的生长,旺长期和成熟期根系活力以T2处理最大,且显著高于对照。(2)施用生物炭能提高旺长期和成熟期叶片SPAD值,进而促进了烟叶的光合作用。(3)施用生物炭能增加土壤微生物数量,其中T2处理在团棵期和旺长期土壤细菌数量、团棵期和成熟期土壤真菌数量均显著高于CK。3 750 kg/hm^2用量(T2)的生物炭施用效果最好。

To explore the application of carbon in soil micro-ecological environment and growth offlue-cured tobacco in Xiangxi Autonomous Prefecture under deep tillage conditions,cloud87was used as the test material,under the condition of30cm of tillage depth,a comparison was made among the treatments of3000kg/hm^2(T1),3750kg/hm^2(T2)and4500kg/hm^2(T3)and non-application of biological carbon(CK).The dynamic changes of root vigor,leaf SPAD value and soil microbial quantity in the3growth periods of flue-cured tobacco were studied under the condition of deep tillage.The results were as follows.(1)The application of bio-carbon under the condition of deep tillage could promote the growth of the root system of flue-cured tobacco,and the root vigor in the fast growth period and the mature period in T2was the highest,and significantly higher than that of the control.(2)The application of bio-carbon could improve the SPAD value of leaf in the fast growth period and the mature period,and then thus promoting the photosynthesis of tobacco leaf and prolonging the maturity of tobacco leaf.(3)The amount of soil microorganism could be increased by using biochar,among the treatments the number of soil bacteria of T2in the rosette period and the fast growth period,and the number of fungi in the rosette period and the mature period were significantly larger than those of the CK.The dosage of3750kg/hm^2(T2)of biological carbon application had the best effect.