Soil properties and crop yields after 11 years of no tillage farming in wheat–maize cropping system in North China Plain

Soil deterioration and the accompanying decline in crop yields are the main factors limiting the further development of agriculture in North China Plain. The long-term effects of no tillage (NT) and conventional tillage (CT) on soil properties and crop yields were investigated in annual double cropping system of winter wheat–summer maize in the Gaocheng in Hebei, North China Plain over a 11-year period (1998–2009). Long-term NT significantly (P < 0.05) increased soil organic matter, available N and P in the top 10 cm by 16.1%, 31.0% and 29.6% as compared to CT treatment. Mean percentage of macro-aggregates (>0.25 mm, +8.1%) and macroporosity (>60 μm, +43.3%) was also enhanced statistically (P < 0.05) in the 0–30 cm soil layer. Winter wheat and summer maize yields tended to be 3.5% and 1.4% higher under NT than under CT, particularly in the dry years, suggesting that the change in soil physical properties, soil fertility and moisture has provided a better environment for crop development. These improvements in soil properties and yields are of considerable importance for the degraded soils in semiarid North China Plain, as well as for food security, sustainable agriculture and carbon storage in the annual double cropping areas of China.