镁肥与添加剂施用后土壤镁迁移与淋洗特征研究

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

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。

The availability and translocation leaching of Mg were studied in the lab by soil column simulating test treated with Mg fertilizer,different amounts of biochar,organic fertilizer and lime.The results showed that applying additives increased pH values of the fertilized soil layers(0–15 cm).Applying Mg fertilizer,biochar,50%required lime,3.3 g/kg and 6.6 g/kg organic fertilizer increased significantly exchangeable Mg content in the fertilized soil layer,while applying 10 g/kg organic fertilizer,100%and 200%required lime decreased it,and exchangeable Mg content in the topsoil layer ranged from 14.61 to 126.03 mg/kg.Appling organic fertilizer and lime enhanced the migration ability of Mg.The content of exchangeable Mg in soil layer(15–50 cm)without fertilizer additive accounted for 64%–86%of the total soil column,while only 62%in the control treatment.Mg leaching with applying biochar was the highest,and it was proportional to the applied amount of biochar,while applying lime reduced Mg leaching,which was up to 7.95%lower than CK.Applying organic fertilizer obtained the highest leaching rate(46.58%)and the lowest fixed rate(49%)of Mg.Applying biochar got the maximum released amount of Mg(507.4 mg),which was proportional to the applied amount of biochar.The released amount of Mg with applying lime and organic fertilizer was 101–156 mg.In conclusion,the released amount of Mg and the available Mg content in soil were the highest with applying biochar while the leached amount and the leaching rate of Mg with applying lime were the lowest.