Effects of Strip Tillage on Soil Physical Properties and Maize Yield in Thin-layer Black Soil

Abstract

【Objective】The research was performed to investigate the effects of planting year (Y) and tillage mode (T) on soil improvement and maize yield in thin-layer black soil in the southern part of the Songliao Plain.【Method】Three tillage modes namely strip-tillage (ST), conventional ridge planting (CT) and no-tillage (NT) were conducted to analyze the changes in soil physical properties and yield traits through field location experiment.【Result】The results showed no significant differences were found in the thickness of soil layers (TSL) and soil water holding capacity (SWHC) of the tillage layer under treatments of ST, NT and CT in 2-year cultivation field, while the results were opposite in 4-year cultivation field, with TSL and SWHC increasing by 15.46% and 30.28% under ST compared with that of CT, whereas no difference was observed between ST and NT. For 0-20 cm depth soil, the soil penetration resistance (PR) under ST treatment increased by 57.57% and 42.86% in the 2-year and 4-year cultivation fields, compared with that under CT treatment, while decreased by 5.22% and 19.22% compared with that under NT treatment. And no significant differences were observed in soil bulk density (BD) and soil porosity (SP) between the 2-year and 4-year cultivation fields under the three treatments. For the 20-40 cm depth soil, only BD under ST treatment in 4-year cultivation field was 11.56% lower than that of CT, whereas no difference was found between ST and NT. The PR under ST in 2-year and 4-year cultivation fields were 5.22% and 19.22% lower than that of CT, respectively, while SP increased by 11.8% and 15.92%, correspondingly. Compared with treatments of CT and NT, maize yield under ST in 2-year cultivation field increased by 3.62% and 3.52%, respectively, and that in 4-year cultivation field increased by 16.08% and 9.29%, respectively. From the results of yield components, the increase in effective ear number per unit area was the main factor for the increase of maize yield under ST treatment. The analysis of the random forest model further demonstrated that the TSL and PR in plough layer were the most important factors affecting maize yield with 2-year and 4-year cultivation.【Conclusion】In conclusion, ST is beneficial for the formation of better plough layer and enhancement of maize yield in thin-layer black soil farmland.

Keywords

• black soil
• straw returning
• cultivated land quality
• strip-tillage
• conservation tillage
• yield