The utilization of pig slurry (PS) as an organic fertilizer plays a pivotal role in nutrient recycling within agricultural systems. However, this practice concomitantly leads nitrogen (N) losses through ammonia (NH₃) volatilization and nitrous oxide (N₂O) emissions. The objective of this study was to investigate the effect of wood biochar on mitigating NH3 and N2O emissions and enhancing N retention from PS-applied soil, and plant biomass production during the vegetative growth of rapeseed (Brassica napus L.). The experiment consisted of three treatments: 1) water (non-PS), 2) PS, and 3) PS combined with wood biochar (PS+WB). The PS+WB treatment resulted in the maintenance of elevated soil water content during the experimental period. The PS+WB treatment significantly enhanced soil nitrogen retention compared to PS alone, maintaining higher total N and NH₄⁺-N levels while reducing NO₃⁻ -N accumulation. Wood biochar application also leds to substantial reductions in NH₃ and N₂O emissions, mitigating environmental N losses. The PS+WB treatment resulted in an improvement of shoot biomass, crude protein content, and total digestible nutrients, indicating enhanced forage quality. The increased soil moisture content in PS+WB further contributed to plant growth benefits. These findings demonstrate that wood biochar is an effective amendment for improving nitrogen retention, reducing gaseous N emissions, and enhancing crop productivity in PS-amended soils.

ABSTRACT
Ⅰ. INTRODUCTION
Ⅱ. MATERIALS AND METHODS
    1. Soil and material preparation
    2. Experimental design
    3. Sample collection: forage, soil, and gas
    4. Chemical and analytical methods
    5. Measurement of NH₃ and N2O emissions
    6. Statistical analysis
Ⅲ. RESULTS
    1. Soil water content
    2. Soil nitrogen dynamics
    3. Ammonia (NH3) and nitrous oxide (N2O) emissions
    4. Shoot biomass and nitrogen content
Ⅳ. DISCUSSION
Ⅴ. CONCLUSIONS
Ⅵ. ACKNOWAGEMENTS
Ⅶ. REFERENCES

• Sang-Hyun Park(Grassland Science Lab, Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture)
• Tae-Hwan Kim(Grassland Science Lab, Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture)
• Bok-Rye Lee(Grassland Science Lab, Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture) Corresponding author
• Muchamad Muchlas(Grassland Science Lab, Department of Animal Science, Institute of Agricultural Science and Technology, College of Agriculture, Faculty of Animal Science, University of Brawijaya, Veteran Street, Malang, East Java 65145, Indonesia)