秸秆生物炭对砂姜黑土有机磷组分含量的影响

研究秸秆生物炭对砂姜黑土有机磷组分及分配的影响，对剖析土壤磷循环机制和农田磷管理有重要意义。依托砂姜黑土定位试验，分析不施肥（CK）、常规施肥（NPK）、化肥与6.0、12、36和48 t·hm^-2小麦秸秆生物炭一次性增施（BC₆、BC₁₂、BC₃₆和BC₄₈）6个处理对作物产量、土壤理化性质及有机磷组分的影响。结果表明，与NPK处理相比，增施秸秆生物炭均可保障小麦和玉米产量，并显著增加（P < 0.05）土壤有机碳、全氮和pH，提升土壤肥力和缓解土壤酸化；砂姜黑土有机磷以中等活性有机磷为主（37.4%～45.4%），其分配比例因秸秆生物炭施用量的不同而呈现差异。BC₆、BC₁₂、BC₃₆和BC₄₈处理土壤活性有机磷含量分别为11.4、10.7、9.2和9.3 mg·kg^-1，分别较NPK处理下降8.8%、14.4%、26.4%和25.6%，差异显著（P＜0.05），且土壤活性有机磷含量与生物炭施用量呈显著线性负相关（R² = 0.881 6，P＜0.05）。增施秸秆生物炭处理（BC₆、BC₁₂、BC₃₆和BC₄₈）土壤活性有机磷所占比例较NPK处理均显著降低（P＜0.05），这说明增施秸秆生物炭除了可有效提升土壤肥力水平、缓解土壤酸化之外，还可有效降低土壤有机磷活性，增强有机磷稳定性，保障作物产量，其中以一次性增施36 t·hm^-2效果最好，宜在砂姜黑土区广泛应用。

Effects of straw biochar application on organic phosphorus fractions and distribution in lime concretion black soil

Understanding the effects of straw biochar on soil organic phosphorus fractions and distribution in lime concretion black soil is of great significance to analyze the soil phosphorus cycle mechanism and excavate the availability of soil phosphorus pool. In this study, the effects of no fertilization (CK), conventional fertilization (NPK), chemical fertilizer and one-time addition of wheat straw biochar (BC₆, BC₁₂, BC₃₆ and BC₄₈) on crop yield, soil physicochemical properties and organic phosphorus components were analyzed based on field experiments on lime concretion black soil. The results showed that, compared with NPK treatment, increased application of straw biochar could guarantee wheat and maize yields, significantly increase (P < 0.05) the soil organic carbon, total nitrogen and pH, and improve the soil fertility and alleviate the soil acidification. The proportion of organic phosphorus in lime concretion black soil was mainly medium labile organic phosphorus (37.4% - 45.4%). The proportion of organic phosphorus in lime concretion black soil was different with different application amount of straw biochar. The contents of labile soil organic phosphorus in BC₆, BC₁₂, BC₃₆ and BC₄₈ treatments were 11.4, 10.7, 9.2 and 9.3 mg·kg^-1, respectively, which were 8.8%, 14.4%, 26.4% and 25.6% lower than that in NPK treatment, respectively. The difference was striking (P < 0.05). There was a significant negative linear correlation between the soil labile organic phosphorus content and the application amount of biochar (R² = 0.881 6, P < 0.05). Increasing straw biochar application processing (BC₆, BC₁₂, BC₃₆ and BC₄₈) and the proportion of soil labile organic phosphorus in NPK treatment were significantly decreased (P < 0.05), suggesting that increasing straw biochar could effectively enhance the level of the soil fertility, soil acidification