Effect of No-Tillage on Soil Bacterial Community Structure in the Black Soil Region of Northeast China

To assess the effects of prolonged no-tillage practices on soil health and crop output, an 18-year field study was carried out in the black soil region of Northeast China. We investigated the variations in soil physicochemical properties, bacterial community structure, and soybean yield under different no-tillage (NT) durations from year 10 to 18 and conventional tillage (CT) treatments for 18 years. The findings indicated that the 18-year no-tillage (NT18) treatment resulted in significantly greater levels of soil organic matter, total nitrogen, and available phosphorus—18.3%, 30.4%, and 65.8% higher, respectively (p < 0.05)—compared to the traditional tillage (CT18) treatment. In the 0–30 cm soil layer, the relative abundance of Acidobacteriota had risen with the duration of no-tillage, whereas Proteobacteria, Gemmatimonadota, and Verrucomicrobiota had shown a decline. In addition, no-tillage treatments increased network complexity, with longer durations of no-tillage leading to higher levels of complexity. Soybean yield increased by 8.5% under NT18 compared to CT18 (p < 0.05). These findings provide insights into the interaction between no-tillage treatments and soil bacterial microbial communities within the black soil region, thereby establishing a solid foundation for developing efficient, ecological, and sustainable conservation tillage systems in Northeast China.