湖南花垣烟区秸秆生物炭配施量对土壤pH及烤烟根系的影响

通过3年大田定位试验，研究不同秸秆生物炭用量（0、3000、3750和4500kg/hm²）对湖南花垣云烟87烟田土壤酸性及烤烟根系的影响。结果表明，添加秸秆生物炭可提高土壤pH，且随着用量的增加及移栽时间的延长，土壤pH呈升高趋势，影响区域主要集中在水平方向距离茎基部0~10cm的土层中，垂直方向上层次越深则响应越滞后。其中，3750和4500kg/hm²处理可降低土壤水解性酸的含量，降幅分别为1.92%和3.21%。秸秆生物炭处理对根系的分布影响水平方向集中在茎基部0~20cm的土层中，垂直方向集中在茎基部0~30cm的土层中。秸秆生物炭主要影响土壤pH，不能改变根系的总体分布，但能有效促进根系的生长，特别是水平方向0~ 10cm、垂直方向0~10和20~30cm处的根系。花垣紫色土的秸秆生物炭经济适宜用量为3750~ 4500kg/hm²。本研究可为秸秆生物炭经济配施法提供理论参考。

Effects of Fertilizing with Straw Biochar on Soil pH and Root Growth of Flue-Cured Tobacco in Huayuan,Hunan

In Huayuan, a three years fixed-site field experiment was conducted to examine the effects of varying economic amount of straw biochar (0, 3000, 3750 and 4500kg/ha) on soil pH and root development of the Yunyan 87 flue-cured tobacco variety. The findings indicated that the soil pH was incresed with straw biochar treat, and the soil pH showed the trend of increasing with the increase of aplication amount and the extension of transplanting time. The deeper hierarchy responded more slowly and the predominant affection region was in areas 0-10cm away from the stem in horizontal direction. Treatments with 3750 and 4500kg/ha reduced hydrolytic acid by 1.92% and 3.21%, respectively. The straw biochar treat effected tobacco roots distribution was mainly in the area of 0-20cm away from stem horizontally, and 0-30cm away from stem vertically. Straw biochar mainly affected the soil pH value, and did not change the overall distribution of tobacco root but regulated root development status effectively, especially in the areas of 0-10 and 20-30cm away from stem in vertical direction and 0-10cm away from stem in horizontal direction. The economic appropriate amount of straw biochar was 3750-4500kg/ha in Huayuan purple soil. This study offers the theoretical reference for economical appropriate application of straw biochar.