Soil microbes drive biological functions that mediate chemical and physical processes necessary for plants to sustain growth. Laboratory soil respiration has been proposed as one universal soil health indicator representing these functions, potentially informing crop and soil management decisions. Research is needed to test the premise that soil respiration is helpful for profitable in‐season nitrogen (N) rate management decisions in corn (Zea mays L.). The objective of this research was two‐fold: (i) determine if the amount of N applied at the time of planting effected soil respiration, and (ii) evaluate the relationship of soil respiration to corn yield response to fertilizer N application. A total of 49 N response trials were conducted across eight states over three growing seasons (2014–2016). The 4‐day Comprehensive Assessment of Soil Health (CASH) soil respiration method was used to quantify soil respiration. Averaged over all sites, N fertilization did not impact soil respiration, but at four sites soil respiration decreased as N fertilizer rate applied at‐planting increased. Across all site‐years, soil respiration was moderately related to the economical optimum N rate (EONR) (r² = 0.21). However, when analyzed by year, soil respiration was more strongly related to EONR in 2016 (r² = 0.50) and poorly related for the first two years (r² < 0.20). These results illustrate the factors influencing the ability of laboratory soil respiration to estimate corn N response, including growing‐season weather, and the potential of fusing soil respiration with other soil and weather measurements for improved N fertilizer recommendations.

中文翻译：

---

将美国中西部49个田地的四天土壤呼吸与玉米氮肥需求相关联

土壤微生物驱动生物功能，这些功能介导植物维持生长所必需的化学和物理过程。已提出实验室土壤呼吸作为一种通用的土壤健康指标，代表了这些功能，有可能为作物和土壤管理决策提供依据。研究是需要测试的前提是土壤呼吸是有利可图的反季节氮（N）玉米率管理决策（有用玉米L.）。这项研究的目的有两个：（i）确定种植时施用的氮素量是否影响土壤呼吸，以及（ii）评估土壤呼吸量与施氮对玉米产量反应的关系。在三个生长季节（2014-2016年）内，在八个州进行了总共49 N响应试验。为期4天的土壤健康综合评估（CASH）土壤呼吸方法用于量化土壤呼吸。在所有地点平均施用氮肥不会影响土壤呼吸，但是在四个地点，随着种植时氮肥施用量的增加，土壤呼吸作用降低。在所有站点年中，土壤呼吸与经济最佳氮素含量（EONR）呈中等相关性（r ² = 0.21）。但是，按年份进行分析时，2016年土壤呼吸与EONR的相关性更强（r ²  = 0.50），而在头两年中与土壤呼吸的相关性较弱（r ²  <0.20）。这些结果说明了影响实验室土壤呼吸估算玉米氮响应能力的因素，包括生长季节的天气，以及将土壤呼吸与其他土壤和天气测量结果融合以改善氮肥建议的潜力。