The combination of conservation tillage (non-inversion and no-till) with organic farming is rare due to weed problems. However, both practices have the potential to improve soil quality and increase soil organic C (SOC). This study investigated the changes in SOC, microbial biomass, and microbial composition during the transition from conventional to organic farming (from 2014 to 2020) in a long-term tillage trial established in 1999. Non-inversion minimum tillage to a depth of 10 cm (MT) resulted in SOC stratification, whilst conventional soil tillage with 25-cm-deep mouldboard ploughing (CT) maintained an even SOC distribution in the plough layer. After 12 years of contrasting tillage in 2011, the uppermost soil layer under MT had a 10% higher SOC content (1.6% w/w) than CT (1.45% w/w). This difference became even more pronounced after introducing organic farming in 2014. By the fall of 2020, the SOC content under MT increased to 1.94%, whilst it decreased slightly to 1.36% under CT, resulting in a 43% difference between the two systems. Conversion to organic farming increased microbial biomass under both tillage systems, whilst SOC remained unchanged in CT. Abundances of total bacterial and Crenarchaeal 16S rRNA and fungal ITS genes indicated shifts in the microbial community in response to tillage and depth. Fungal communities under MT were more responsive to organic farming than bacterial communities. The improved soil quality observed under MT supports its adoption in both organic and conventional systems, but potentially large yield losses due to increased weed cover discourage farmers from combining MT and organic farming.

由于杂草问题，保护性耕作（不倒转和免耕）与有机农业的结合很少见。然而，这两种做法都有改善土壤质量和增加土壤有机碳（SOC）的潜力。本研究在 1999 年建立的长期耕作试验中调查了从传统农业向有机农业过渡（2014 年至 2020 年）期间 SOC、微生物生物量和微生物组成的变化。非反转最小耕作深度为 10 厘米(MT) 导致 SOC 分层，而采用 25 厘米深犁耕 (CT) 的传统土壤耕作则保持耕层中 SOC 的均匀分布。经过 2011 年 12 年的对比耕作，MT 下最上层土壤的 SOC 含量（1.6% w/w）比 CT 下（1.45% w/w）高 10%。这种差异在 2014 年引入有机农业后变得更加明显。到 2020 年秋季，MT 下的 SOC 含量增加到 1.94%，而 CT 下的 SOC 含量略有下降至 1.36%，导致两个系统之间存在 43% 的差异。转向有机农业增加了两种耕作系统下的微生物生物量，而 CT 中的 SOC 保持不变。总细菌和穹窿菌 16S rRNA 以及真菌 ITS 基因的丰度表明微生物群落因耕作和深度而发生变化。MT 下的真菌群落比细菌群落对有机农业的反应更敏感。MT 所观察到的土壤质量得到改善，支持其在有机和传统系统中的采用，但由于杂草覆盖增加，潜在的巨大产量损失阻碍了农民将 MT 与有机农业结合起来。