两种生物质炭对果园土壤氮素淋失、滞留的影响

Effects of Two Types of Biochar on Soil Nitrogen Leaching and Retention in Apple Orchard

[目的]为了研究生物质炭对果园土壤氮素淋失、滞留的影响。[方法]基于土柱淋溶模拟试验,研究两种不同生物质炭——稻壳炭和苹果枝条炭的施用(11 mg/kg)及其与化肥(6.6 g/kg)混施对果园土壤氮素淋失速率和滞留量的影响。[结果]单独施用生物质炭对土壤氮素的淋失和滞留影响较小;生物质炭与化肥混施后,NH_4^+-N的淋失总量增加了39.3%~44.0%,在20~40 cm土层的滞留量减少了21.7%~28.8%;稻壳炭促使NO_3^--N的淋失量和20~40 cm土层的滞留量分别增加了18.0%、43.3%,苹果枝条炭促使NO_3^--N的淋失总量和20~40 cm土层的滞留量分别减少了13.4%、12.1%;施用生物质炭增加了土壤的持水能力。[结论]生物质炭本身对土壤氮素的动态影响较小;与化肥混施增加了NH_4^+-N的淋失风险,NO_3^--N的淋失和滞留与生物质炭的种类有关。

[ Objective] The research aimed to investigate the effects of biocbar addition on orchard soil nitrogen leaching and retention. [ Method] Two different types of biochar： flee-hull-based and apple-branch-based charcoals were selected to a column incubation experiment through their addition （11 mg/kg） mixing with chemical fertilizers （6.6 g/kg）. [ Result] The ddition of biochar had a small effect on the leaching and retention of soil nitrogen. While addition with chemical fertilizer, the leaching amount of NH4＋ -N was increased by 39.3% -44.0% and the re- tention amountin 20 -40 cm layer was decreased by 21.7% -28.8%. Rice-hull-basedcharcoal prompted NO3 - -N leaching loss and retention amount in 20 -40 cm layer increasing by 18.0% and 43.3%, respectively. For apple-branch-based charcoal, they decreased by 13.4% and 12. 1%. [ Conclusion] The addition of biochar had a small effect on soil nitrogen dynamics. Biochar mixed with fertilizer increased the leaching risk of NH4＋ -N, while the leaching and retention of NO3 - -N might be related to the type of biochar.