Effects of biochar on nitrogen and phosphorus retention in the coastal wetland soil of the Yellow River Delta, China

Nutrient deficiency (nitrogen, phosphorus) strongly limited the productivity of the degraded coastal soils in the Yellow River Delta. Biochar (BC) is a kind of porous carbonaceous material. It has raised wide interests because of their multiple benefits in soil improvement. The effects of biochar on the retention of nitrogen and phosphorus varied with the types of biochar and soil properties. In this study, a maize straw derived BC was applied into a coastal salt-affected soil collected from the Yellow River Delta to investigate the response of soil nutrient using a three-month cultivating experiment with the simulated rainfall. The results showed that the addition of biochar reduced the content of NH4+-N and NO3--N in all-depth soil by 8.1–27.0% and 25.3–51.9%, respectively. The content of TP in 0-30 cm soil was significantly increased, while it had no significant effect on the content of TP in 30-60 cm soil. These findings would provide theoretical basis and technical support for developing feasible technologies for remediating degraded coastal wetland soil