The effect of different rates of biochar on selected soil properties and enzymatic activity 48, 60, and 72 months after biochar application to soil was investigated. Soil enzymatic activity (dehydrogenase—ADh; phosphatase—Aph; urease—AU), the organic carbon content (TOC), the total nitrogen content (N_t), the mineral nitrogen content (NH₄⁺, NO₃⁻), and soil pH were determined. The study was conducted on Haplic Podzol originating from glaciofluvial fine-grained loamy sand. Biochar was applied to soil under winter rye (Secale cereale L.) at rates of 10 (BC₁₀), 20 (BC₂₀), and 30 t ha⁻¹ (BC₃₀). Plots with biochar-unamended soil were the control treatment (BC₀). The pH, TOC, and N_t content in the biochar-amended soil were higher compared to the control soil. A broader C:N ratio was found in the BC₀ soil compared to BC₁₀, BC₂₀, and BC₃₀. With increasing biochar rate, the content of the ammonium nitrogen form (NH₄⁺) decreased and was statistically lower than in the control soil (BC₀). The soil in the BC₂₀ and BC₃₀ treatments was characterized by the highest content of NO₃^-, whereas the lowest nitrate nitrogen content was found in the control soil (BC₀). Biochar application increased soil enzymatic activity. Dehydrogenase activity increased with increasing biochar rate. As far as phosphatase and urease activity is concerned, a similar relationship was not observed. In this case, the soil amended with biochar at a rate of 20 t ha⁻¹ (BC₂₀) was characterized by the highest phosphatase and urease activity.

中文翻译：

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生物炭自然老化对长期田间试验土壤酶活性和理化特性的影响

研究了不同生物炭比率对生物炭施用到土壤后48、60和72个月对选定土壤特性和酶活性的影响。土壤酶活性（脱氢酶-ADH;磷酸酶APH;脲酶AU）中，有机碳含量（TOC），总氮含量（N_吨），矿物氮含量（NH ₄ ⁺，NO ₃ ^- ），和土壤测定pH。这项研究是对源自河道细粒壤质砂的Haplic Podzol进行的。将生物炭以10（BC ₁₀），20（BC ₂₀）和30 t ha ^-1（BC ₃₀）的比例施用于冬天黑麦（Secale graine L.）下的土壤）。含生物炭改良土壤的样地为对照处理（BC ₀）。pH值，TOC，和N_吨相比于对照土壤中生物炭修订的土壤中的含量较高。与BC ₁₀，BC ₂₀和BC ₃₀相比，在BC ₀土壤中发现了更宽的C：N比。随着生物炭速率的增加，铵态氮形式（NH ₄ ⁺）的含量降低，且统计学上低于对照土壤（BC ₀）。BC ₂₀和BC ₃₀处理的土壤特征在于NO _3-的含量最高^。，而对照土壤中的硝酸盐氮含量最低（BC ₀）。生物炭的施用增加了土壤的酶活性。脱氢酶活性随着生物炭速率的增加而增加。就磷酸酶和脲酶活性而言，未观察到类似的关系。在这种情况下，以20 t ha ^-1（BC ₂₀）的速率对生物炭进行改良的土壤具有最高的磷酸酶和脲酶活性。