The Effect of Sago Peel Waste Biochar Dose on pH, Total N, Available P, and K-dd of Kambisol Soil

This study aims to examine the effect of sago husk waste biochar dosage on the chemical properties of Kambisol soil. Observed parameters included pH, total N, available P, and K-dd soil after a 30-day incubation period. The study was conducted using a one-factor Completely Randomized Design (CRD) with five biochar dosage levels, namely 0, 5, 10, 15, and 20 g kg⁻¹ soil. The results showed that increasing the biochar dosage had a positive effect on improving the chemical quality of Kambisol soil. Increasing the dosage showed an upward trend in all test parameters. The soil pH value increased from 5.12 to 5.95 at the highest dose treatment. The total N concentration increased from 0.16 % to 0.21%. Available P availability increased significantly from 8.30 mg kg⁻¹ to 17.50 mg kg⁻¹. Furthermore, soil K-dd content also increased from 0.18 cmol (+) kg⁻¹ to 0.45 cmol(+) kg⁻¹. These findings indicate that sago peel-based biochar is highly effective in increasing fertility and nutrient retention in acidic soils.