Effects of Strategic Tillage on Soil Physicochemical Properties and Grain Yield in the North China Plain

No-till (NT) practice has been widely adopted to improve soil quality, but soil compaction and soil organic carbon (SOC) stratification under long-term NT limit crop production. Strategic tillage (ST), based on single tillage, is proposed as an attractive management practice to sustain the benefits of continuous NT and mitigate its adverse effects. Four tillage systems, including continuous rotary tillage (RT), NT, rotary tillage + subsoiling (RS), and no-till + subsoiling (NS), were implemented to investigate the effects of strategic tillage (i.e., RS and NS) on soil physical properties (compaction and aggregates), SOC, and crop yield in the North China Plain (NCP). The results showed that ST as expected decreased soil bulk density, penetration resistance, and SOC stratification compared with RT and NT at 0-20 cm soil depth (p< 0.05). At 0-10 cm soil depth, more macroaggregates (>0.25 mm) were observed in NT and NS, contributing to higher mean weight and geometric mean diameters, this compared with RT and RS. Additionally, macroaggregate associated SOC was higher, thus resulting in higher SOC storage in NT (31.4-33.4 Mg ha(-1)) and NS (33.3-35.4 Mg ha(-1)) at 0-30 cm depth (p< 0.05). Low soil compaction and high SOC in NS were beneficial for the grain yield of wheat and maize, significantly higher by 8.7-32.5% and 14.0-29.8% compared with the other treatments, respectively (p< 0.05). Based on our findings, NS seems to be a promising alternative tillage system to improve soil physicochemical properties and crop production in the NCP. More studies are therefore needed to better understand the benefit of NS.