A better understanding of how land management might affect soil respiration can greatly help enhancing the long-term sustainability of agricultural soils. This study investigated the effects of two key management practices, nutrient fertilization and soil tillage, on soil respiration in an intensive grassland system. Data were collected from a long-term grassland experiment established in 1970 in Northern Ireland, UK. The experiment commenced with eight nutrient treatments: an unfertilised control, inorganic fertiliser (NPK), two types of slurry: cattle and pig slurry at three application rates. In September 2019 half of the experimental plots were tilled and reseeded with a multi-species sward mixture. Static automated chambers were used to measure the fluxes of CO between 2018 and 2021. Surprisingly, we did not find any significant nutrient treatment effects on mean hourly or cumulative CO emissions. Likewise, there were no significant differences in CO emissions between the type of slurry, slurry application rate or the interaction of these treatment factors. However, seasonal changes in CO emissions were highly significant while ploughing had a significant decreasing effect on the cumulative daily CO emissions but only during the establishment period (first nine weeks). Significant relationships with CO flux were found for soil temperature and soil water content. We also found no relationship between short-term soil CO emissions and long-term soil organic carbon storage data, which highlights the complexity of soil C source-sink dynamics and C balance. Our study brings evidence that regarding CO emissions the impact of soil tillage is short-lived, and the direct effect of nutrient additions is small.

中文翻译：

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长期草地试验中养分施肥和土壤耕作对土壤CO2排放的影响


更好地了解土地管理如何影响土壤呼吸可以极大地帮助提高农业土壤的长期可持续性。本研究调查了两种关键管理措施（养分施肥和土壤耕作）对集约化草地系统土壤呼吸的影响。数据来自 1970 年在英国北爱尔兰建立的长期草原实验。该实验从八种营养处理开始：未施肥的对照、无机肥料（NPK）、两种类型的泥浆：三种施用率的牛和猪泥浆。 2019 年 9 月，一半的实验田进行了耕种，并重新播种了多物种草皮混合物。使用静态自动化室来测量 2018 年至 2021 年间的二氧化碳通量。令人惊讶的是，我们没有发现营养处理对平均每小时或累积二氧化碳排放量有任何显着影响。同样，不同浆料类型、浆料施用率或这些处理因素的相互作用之间的二氧化碳排放量没有显着差异。然而，CO 排放量的季节变化非常显着，而耕作对累积日 CO 排放量有显着的降低作用，但仅限于建植期（前 9 周）。土壤温度和土壤含水量与二氧化碳通量存在显着关系。我们还发现短期土壤二氧化碳排放与长期土壤有机碳储存数据之间没有关系，这凸显了土壤碳源汇动态和碳平衡的复杂性。我们的研究提供的证据表明，就二氧化碳排放而言，土壤耕作的影响是短暂的，并且养分添加的直接影响很小。