镁肥与添加剂施用后土壤镁迁移与淋洗特征研究

通过室内土柱试验,模拟了镁肥及不同用量添加剂包括生物质炭、有机肥、石灰施用土壤后镁素的有效性及迁移淋溶特征。结果表明:施用添加剂后均不同程度提高施肥土层(0~15 cm)土壤pH。施用镁肥、生物质炭、50%需求量石灰与3.3、6.6 g/kg有机肥后,施肥土层交换性镁含量显著增加,而10 g/kg有机肥与100%、200%需求量石灰施用则降低施肥土层交换性镁含量;各处理土壤表层交换性镁含量范围为14.61~126.03 mg/kg。施用有机肥与石灰后,镁的迁移能力增强,未施用肥料添加剂土层(15~50 cm)土壤交换性镁含量占土柱总量的64%~86%,而对照处理仅为62%。施入生物质炭后,镁淋失量最高,且与施用量呈正比;施用石灰则降低土壤镁淋失,与对照处理相比,最高可降低7.95%;施用有机肥镁淋失率最高为46.58%,固定率最低为49%;施用生物质炭后镁释放量最高为507.4 mg,与添加量呈正比,而石灰、有机肥处理镁释放量为101~156 mg。综合分析,施用生物质炭后,镁释放量与土壤有效镁含量最高;施用石灰后,镁淋失量最少,淋失率最低。

Study on Migration and Leaching of Magnesium in Soil Treated by Magnesium Fertilizer and Additives

It is very important for agricultural production to increase effective magnesium content and reduce magnesium leaching loss in acidic soil in south China. In this paper, the availability of soil magnesium and characteristics of translocation leaching of magnesium fertilizer, different amounts of biochar, organic fertilizer and lime in soil were simulated by laboratory soil column test. The results showed that the pH value of the fertilized soil layer (0 ~15 cm) was increased after the application of additives. After applying magnesium fertilizer, biochar, 50% required lime and 3.3g/kg and 6.6g/kg organic fertilizer, exchangeable magnesium content in the fertilized soil layer increased significantly. Applying 10g/kg organic fertilizer and 100% and 200% required lime decreased exchangeable magnesium content in the fertilized soil layer, and exchangeable magnesium content in the soil surface ranged from 14.61 to 126.03 mg/kg. After the application of organic fertilizer and lime, the migration ability of magnesium was enhanced. Without the application of fertilizer additive soil layer (15 ~50 cm), the content of exchangeable magnesium in soil accounted for 64% ~ 86% of the total soil column, and only 62% in the control treatment. After applying biochar, the magnesium leaching amount was the highest, which was proportional to the applied amount. Applying lime could reduce the soil magnesium leaching amount, which was up to 8% lower than the control treatment. Applying organic fertilizer, the magnesium leaching rate was 46.6% at the highest, and the fixed rate was 49% at the lowest. The maximum amount of magnesium released after applying biochar was 507.4mg, which was in direct proportion to the addition amount. The amount of magnesium released after applying lime organic fertilizer was 101~156mg. After applying biochar, the release amount of magnesium and the available magnesium content in soil were the highest.After applying lime, the amount of magnesium leaching was the least and the leaching rate was the lowest.