Department of Soil and Crop Sciences, C127 Plant Sciences Building, Colorado State University, Fort Collins, CO 80523-1170, United States of America.
Coastal Plains Soil, Water, and Plant Research Center, Agricultural Research Service, USDA, Florence, SC 29501, United States of America.
Sci Total Environ. 2021 Oct 15;791:148344. doi: 10.1016/j.scitotenv.2021.148344. Epub 2021 Jun 8.
Soil health assessments associated with organic amendment applications have primarily focused attention on manure or composts. Yet, quantifying specific changes in soil health associated with biosolids land applications has yet to be determined. Our objectives were to evaluate the changes in various soil indicators, and utilizing the Soil Management Assessment Framework (SMAF), quantify changes in soil indicator scores and soil health indices as affected by either increasing inorganic N fertilizer (0 up to 112 kg N ha) or biosolids (0 up to 11.2 dry Mg ha) applied every other year over 22 years. Soils were sampled (0 to 20 cm depth) following 22 years of N fertilizer or biosolids inputs to a dryland wheat-fallow (Triticum aestivum L.) rotation, 11 soil health indicators were monitored under SMAF guidelines, and indicators, indicator scores, and soil health indices were analyzed statistically. In general, increasing N fertilizer application rates had little effect on soil indicators, SMAF indicator scores or soil health indices. Increasing biosolids application rates increased soil organic C (SOC) and potentially mineralizable N (PMN). The SMAF indicator scores showed upward trends for soil pH, SOC, PMN, and microbial biomass C (MBC) associated with increasing biosolids application rates; discussing trends are important as these indicator scores are combined to provide soil health indices. Indeed, increasing biosolids application rates increased soil chemical and biological health indices, leading to an improvement in the overall soil health index. When comparing the overall N fertilizer to biosolids effect, biosolids applications significantly improved the soil biological health index. Results indicate that long-term biosolids land application to semi-arid, dryland wheat fallow rotations, similar to those studied, improve various aspects of soil health. These findings suggest that biosolids may play a pivotal role in dryland agroecosystem sustainability.
与有机肥料施用相关的土壤健康评估主要关注的是粪肥或堆肥。然而，量化与生物固体土地施用相关的土壤健康的具体变化尚未确定。我们的目标是评估各种土壤指标的变化，并利用土壤管理评估框架（SMAF），量化由于每年施用无机 N 肥料（0 至 112kg N ha）或生物固体（0 至 11.2 干 Mg ha）而导致的土壤指标得分和土壤健康指数的变化，连续 22 年。在施氮或生物固体 22 年后，对旱地小麦-休耕（Triticum aestivum L.）轮作中的土壤进行采样（0 至 20cm 深度），根据 SMAF 指南监测 11 个土壤健康指标，统计分析指标、指标得分和土壤健康指数。一般来说，增加 N 肥料施用量对土壤指标、SMAF 指标得分或土壤健康指数影响不大。增加生物固体施用量增加了土壤有机碳（SOC）和潜在可矿化氮（PMN）。SMAF 指标得分显示，随着生物固体施用量的增加，土壤 pH、SOC、PMN 和微生物生物量 C（MBC）呈上升趋势；讨论趋势很重要，因为这些指标得分是组合起来提供土壤健康指数的。事实上，随着生物固体施用量的增加，土壤化学和生物健康指数增加，导致整体土壤健康指数提高。当比较总体 N 肥料和生物固体的影响时，生物固体的应用显著提高了土壤生物健康指数。结果表明，在类似研究的半干旱旱地小麦休耕轮作中，长期施用生物固体可以改善土壤健康的各个方面。这些发现表明，生物固体可能在旱地农业生态系统的可持续性中发挥关键作用。
