Soil quality indicators for Urochloa brizantha fertilized with wood ash

ABSTRACT The objective was to evaluate the effect of wood ash dose and application management on soil quality attributes in a Cerrado area cultivated with Urochloa brizantha. The experiment was carried out in a randomized block design in a 5 × 2 strip-plot scheme and four repetitions. The ash doses were 0, 8, 16, 24, and 32 t ha-1, and the application management considered wood ash that is incorporated and not incorporated into the soil. The P, K, and pH values of the soil increased with an increase in the doses of wood ash. The soil bulk density decreased by 9.66% with the wood ash doses of 24 and 32 t ha-1 incorporated into the soil. Owing to an increase in the soil pH, a wood ash dose of greater than 16 t ha-1 decreased the enzymatic activity. A wood ash dose of 24 t ha-1 resulted in better conditions for the soil, improving its quality and contributing to the balance and dynamics between the chemical, physical, and biological attributes of the soil, which led to the reduced density and greater availability of P in the soil.

摘要 本研究旨在评估木灰施用量与施用方式对塞拉多（Cerrado）稀树草原区域种植布氏臂形草（Urochloa brizantha）的土壤质量属性的影响。试验采用随机区组设计，设置5×2条区（strip-plot）方案，共4次重复。木灰施用量梯度设置为0、8、16、24、32 t·ha⁻¹，施用方式分为土施（将木灰混入土壤）与表施（不混入土壤）两类处理。土壤有效磷、速效钾含量及pH值随木灰施用量提升呈升高趋势。当木灰施用量为24和32 t·ha⁻¹且采用土施方式时，土壤容重降低9.66%。受土壤pH升高的影响，当木灰施用量超过16 t·ha⁻¹时，土壤酶活性出现下降。施用量为24 t·ha⁻¹的木灰可优化土壤微环境，提升土壤质量，促进土壤化学、物理与生物属性间的平衡与动态循环，进而降低土壤容重并提升土壤有效磷的有效性。