生物质炭施用量对旱地酸性红壤理化性质的影响

我国南方旱地酸性红壤区,土壤酸化与干旱等问题突出。近几年生物质炭在土壤改良方面的研究应用已有较多的文献报道,但针对南方旱地酸性红壤区土壤改良方面的研究与应用相对较少。对此,本研究设置了生物质炭施加量分别为1%、2%、3%、4%及对照CK共5个处理,每个处理5次重复的室内盆栽试验;每盆一次性均匀浇洒1 L蒸馏水后在温室内自然放置,模拟干旱30 d,随后测定土壤含水量、p H、电导率与氮、磷含量。结果表明:土壤pH、电导率、有效磷含量随生物质炭施加量的增加而显著提高,NH₄⁺-N含量降低,而NO₃^–-N含量无显著影响;模拟干旱后的土壤含水量与生物质炭施加量呈二次函数曲线关系,施加低量生物质炭(1%)显著降低了土壤含水量,而高量生物质炭(4%)的施加则使土壤含水量显著提高。本研究为生物质炭在我国南方旱地酸性红壤区土壤改良方面的应用提供了试验依据。

Effects of Biochar on Physicochemical Properties of Dry Land Acid Red Soil

The acid red soil is widespread in south China which characterized as low pH and water holding capacity. Biochar, a cheap and widely used carbon-rich material, has shown the potential to ameliorate the degraded soil, but its effects on the dry land acid red soil are still unclear. Hence, a pot experiment of aridity simulation was conducted with different application content of biochar (0, 1%, 2%, 3%, 4%) added in the acid red soil and watered with 1 L distilled water equally, then soil water content, pH, electric conductivity, NH₄⁺-N, NO₃^--N and available phosphorus were measured after one month of aridity simulation. Results showed that soil pH, electric conductivity and available phosphorus increased and NH₄⁺-N decreased significantly with the increase of biochar application, while NO₃^--N changed insignificantly. A quadratic relation was observed between soil water content and the content of biochar application, soil water content was decreased significantly under low application content (1%) but increase significantly under high content of application (4%). This study provides a basis for the biochar application in ameliorating the acid red soil in south China.