Ridge-furrow film mulching combined with biochar addition enhances maize productivity and reduces nitrogen loss, but increases soil moisture consumption in semi-arid areas

Aims

Ridge-furrow film mulching (RFFM) and biochar addition are both effective soil management practices for improving crop yields in dry farming regions. However, they may have different impacts on soil moisture status and nitrogen budget.

Methods

A two-years experiment was conducted on soil water and nitrogen status, maize productivity, and nitrogen utilization through four treatments: FN, flat planting without biochar; FB, flat planting with 9.0 t ha⁻¹ biochar; RN, RFFM without biochar; RB, RFFM with 9.0 t ha⁻¹ biochar.

Results

In the 0–60 cm soil layer, RFFM reduced soil nitrogen storage and increased soil water storage (SWS), while biochar addition was the opposite. A significant interaction was observed between the two measures regarding the reduction of SWS in deep soil (60–200 cm), with the RB significantly increasing the soil desiccation index during the filling stage. Pearson correlation analysis showed that the decrease of SWS in deep soil did not adversely affect crop production, instead, it significantly increased maize productivity and utilization efficiency, while reducing nitrogen loss (P < 0.05). Among them, the RB with the lowest SWS in the deep layer demonstrated the best overall performance, which increased maize yield by 27.2% and nitrogen use efficiency by 21.0%, and reduced NH₃ cmissions by 20.6% and mineral nitrogen residue by 46.9%.

Conclusions

RB is an effective field management strategy to promote soil nitrogen retention and improve nitrogen utilization of maize. However, it is important to remain vigilant about the potential impacts of decreased soil water on future agricultural productivity under this practice.