添加生物质炭不同组分对不结球白菜产量和品质的影响

[目的]本文旨在揭示生物质炭施用对作物产量和品质的影响机制。[方法]通过热水浸提法，将生物质炭中以有机碳为主的"炭骨架"（水洗生物质炭，washed biochar）和以小分子有机物为主的"类植物生长激素"（生物质炭浸提液，biochar extracts）分离，再通过燃烧法将以氮、磷、钾等营养元素为主的"速效养分"（生物质炭灰分，biochar ash）分离。将这些不同的组分添加到高、低2种肥力土壤中，研究其对不结球白菜（简称小白菜）产量、品质及土壤性质的影响。[结果]添加不同生物质炭组分对小白菜地上部生物量和根系生物量没有显著影响，但添加生物质炭浸提液和水洗生物质炭显著提高了高肥力土壤中小白菜的根冠比。添加生物质炭不同组分均显著降低了收获期小白菜地上部硝酸盐含量，不同处理硝酸盐含量降低41%~84%。添加水洗生物质炭提高了高肥力土壤中小白菜地上部维生素C含量；而添加生物质炭浸提液增加了低肥力土壤小白菜地上部维生素C含量。添加生物质炭不同组分均显著提高了收获期小白菜地上部钾含量，不同处理钾含量增加43%~88%。小白菜地上部硝酸盐含量与钾含量呈极显著负相关关系。[结论]添加秸秆生物质炭不同组分对小白菜产量没有显著影响，但降低了小白菜地上部硝酸盐含量，同时提高了钾含量。添加秸秆生物质炭后小白菜地上部钾吸收量的增加可能是硝酸盐含量降低的重要原因。
[Objectives] The objective of this study was to answer why biochar amendment increases crop yield and improves leaf quality. [Methods] Simple methods were used to isolate the different components of biochar. These components include the organic carbon without soluble nutrients (named as washed biochar), soluble nutrients (e. g., nitrogen, phosphorus and potassium)without organic carbon (biochar ash), and the part that is composed of low-molecular-weight organic substances (biochar extracts). We hypothesized that, after amending into soils, the three components could represent the effect of soil physical property improvement (washed biochar), nutrients addition (biochar ash)and hormone stimulation (biochar extracts). A pot trial was conducted to investigate the effect of different biochar components on the yield, leaf quality of non-heading Chinese cabbage (Brassica campestris ssp. chinesis)and soil properties. [Results] Results showed that the addition of different biochar components had no effect on the yield and root biomass of Chinese cabbage. However, in the high fertility soil, biochar extracts and washed biochar addition increased the mass ratio of root to aboveground biomass. The addition of different biochar components decreased the concentrations of nitrate in the above ground biomass by 41%-84%. In the high fertility soil, washed biochar addition increased the concentration of vitamin C in the above ground biomass;while, in the low fertility soil, biochar extracts addition increased the concentration of vitamin C. The addition of different biochar components increased the concentration of K in the above ground biomass by 43%-88% across treatments. There was a significant negative correlation between nitrate and K in terms of their concentration in the above ground biomass. [Conclusions] The addition of different biochar components had no effect on the yield of non-heading Chinese cabbage;however, their addition decreased the concentration of nitrate while