ABSTRACT

Sustainable agriculture requires frequent soil health monitoring. Sensitive, simple, and cheap soil health indicators (SHI) are needed. This work aimed to evaluate permanganate oxidizable carbon (POXC) as SHI through analyzing 1) the magnitude of POXC change due to soil use, as compared to total (SOC) and particulate (POC) organic carbon, and hot-water extractable carbon (HWC), and 2) the relationship between POXC and SOC, POC, HWC, anaerobically mineralized nitrogen (AN), and aggregate stability (AS). Soil samples (0–5 and 5–20 cm) from 32 crop production fields (CPF) and pseudo-pristine areas (PPA) from Mollisols throughout the Southeastern Argentinean Pampas were analyzed: bulk density (BD), change of aggregate mean weight diameter (ΔMWD), SOC, POC, HWC, AN, and POXC. The POXC was negatively related to BD and ΔMWD, and positively, to SOC, POC, HWC, and AN. At 0–20 cm, POXC dropped 22% in CPF respect to PPA, whereas POC, AN, HWC, and SOC decreased 62%, 44%, 35%, and 25%, respectively. The POXC could be used as an SHI, given it was sensitive to the changes produced by cropping and it related to other soil properties that indicate soil health status. Its determination is simple, fast, and cheap, which favors its adoption by soil test laboratories.

摘要

可持续农业需要经常监测土壤健康。需要敏感、简单和廉价的土壤健康指标 (SHI)。这项工作旨在通过分析 1) 与总 (SOC) 和颗粒 (POC) 有机碳以及热水可提取碳 (HWC) 相比，土壤使用引起的 POXC 变化幅度来评估高锰酸盐可氧化碳 (POXC) 作为 SHI )，以及 2) POXC 与 SOC、POC、HWC、厌氧矿化氮 (AN) 和聚集体稳定性 (AS) 之间的关系。分析了来自阿根廷东南部潘帕斯草原的 32 个作物生产区 (CPF) 和假原始地区 (PPA) 的土壤样品（0-5 和 5-20 厘米）：容重 (BD)、总平均重量直径的变化(ΔMWD)、SOC、POC、HWC、AN 和 POXC。POXC 与 BD 和 ΔMWD 呈负相关，与 SOC、POC、HWC 和 AN。在 0-20 cm 处，相对于 PPA，POXC 的 CPF 下降了 22%，而 POC、AN、HWC 和 SOC 分别下降了 62%、44%、35% 和 25%。POXC 可以用作 SHI，因为它对种植产生的变化很敏感，并且与指示土壤健康状况的其他土壤特性有关。它的测定简单、快速、便宜，有利于土壤测试实验室的采用。