Enhanced rock weathering (ERW), the application of crushed silicate rock to soil, can remove atmospheric carbon dioxide by converting it to (bi) carbonate ions or solid carbonate minerals. However, few studies have empirically evaluated ERW in field settings. A critical question remains as to whether additions of crushed rock might positively or negatively affect soil organic matter (SOM)—Earth’s largest terrestrial organic carbon (C) pool and a massive reservoir of organic nitrogen (N). Here, in three irrigated cropland field trials in California, USA, we investigated the effect of crushed meta-basalt rock additions on different pools of soil organic carbon and nitrogen (i.e., mineral-associated organic matter, MAOM, and particulate organic matter, POM), active microbial biomass, and microbial community composition. After 2 years of crushed rock additions, MAOM stocks were lower in the upper surface soil (0–10 cm) of plots with crushed rock compared to unamended control plots. At the 2 sites where baseline pre-treatment data were available, neither total SOC nor SON decreased over the 2 years of study in plots with crushed rock or unamended control plots. However, the accrual rate of MAOM-C and MAOM-N at 0–10 cm was lower in plots with crushed rock vs. unamended controls. Before ERW is deployed at large scales, our results suggest that field trials should assess the effects of crushed rock on SOM pools, especially over multi-year time scales and in different environmental contexts, to accurately assess changes in net C and understand the mechanisms driving interactions between ERW and SOM cycling.

强化岩石风化（ERW）是将碎硅酸盐岩石施用于土壤，可以通过将大气中的二氧化碳转化为（双）碳酸根离子或固体碳酸盐矿物来去除大气中的二氧化碳。然而，很少有研究对现场环境中的战争遗留爆炸物进行实证评估。一个关键问题是，添加碎石是否会对土壤有机质 (SOM) 产生积极或消极影响，土壤有机质是地球上最大的陆地有机碳 (C) 库和大量有机氮 (N) 库。在美国加利福尼亚州的三项灌溉农田田间试验中，我们研究了碎变玄武岩添加物对不同土壤有机碳和氮库（即与矿物相关的有机质，MAOM 和颗粒有机质，POM）的影响。 ）、活性微生物生物量和微生物群落组成。添加碎石 2 年后，与未修正的对照地块相比，碎石地块的上表土（0-10 厘米）中的 MAOM 储量较低。在可获取基线预处理数据的 2 个地点，在碎石地块或未经修改的对照地块的 2 年研究中，总 SOC 和 SON 均未下降。然而，与未修正的对照相比，碎石地块中 MAOM-C 和 MAOM-N 在 0–10 cm 处的累积率较低。在大规模部署战争遗留爆炸物之前，我们的结果表明，现场试验应评估碎石对 SOM 池的影响，特别是在多年的时间尺度和不同的环境背景下，以准确评估净碳的变化并了解驱动机制ERW 和 SOM 循环之间的相互作用。