ABSTRACT

We investigated the influence of slash and burn (SBA) practice on selected soil properties and its influence on the dynamics of mineral nutrients in a typical humid temperate climate region of northeast Japan. Soils were sampled from an SBA site and compared to an adjacent original forest site (control) located in Shonai area, Yamagata Prefecture, from August 2018 to August 2019 with monthly intervals for SBA and bi-monthly intervals for control, except the snow cover period. The results showed that SBA could not evidently affect soil pH, electric conductivity, available phosphorus, exchangeable cations (Ca²⁺, Mg²⁺ and K⁺), and effective cation exchange capacity. This was likely due to the low severity of fire in the SBA site. On the other hand, cultivation of turnip affected seasonal changes of soil NH₄⁺ and NO₃⁻ mainly attributed to crop absorption. Soil MBC and MBN were significantly increased after one month of burning due to available soil nutrients from plant biomass burning which stimulated microbial growth. There were no significant changes in SOC and TN between the clear-cut stage (before SBA), and after one year at the end of the study period. This was largely due to the short turnip cultivation period and the quick covering by succession plants. In conclusion, our results showed the SBA practice affected soil properties in this study was not relatively significant.

摘要

我们调查了刀耕火种 (SBA) 实践对选定的土壤特性的影响及其对日本东北部典型潮湿温带气候区矿质养分动态的影响。从 2018 年 8 月至 2019 年 8 月，从 SBA 站点对土壤进行采样，并与位于山形县庄内地区的相邻原始森林站点（对照）进行比较，SBA 每月间隔一次，控制间隔每两个月一次，积雪期除外. 结果表明，SBA对土壤pH值、电导率、有效磷、可交换阳离子（Ca ²⁺、Mg ²⁺和K ⁺)，以及有效的阳离子交换能力。这可能是由于 SBA 站点的火灾严重程度较低。另一方面，萝卜栽培影响土壤NH ₄ ⁺和NO ₃ ^{- 的}季节变化，主要归因于作物吸收。燃烧 1 个月后土壤 MBC 和 MBN 显着增加，这是由于植物生物质燃烧产生的可用土壤养分刺激了微生物生长。在明确阶段（SBA 之前）和研究期结束一年后，SOC 和 TN 没有显着变化。这主要是由于萝卜栽培期短和演替植物快速覆盖所致。总之，我们的结果表明 SBA 实践对本研究中土壤特性的影响并不显着。