Laboratory experiments were carried

Laboratory experiments were carried out to study the pattern of nitrogen release from urea fertilizer with
biochar application. The soil or soil mixture was put in in soil column of 30 cm length, fertilized with 300 ha-1
urea, and then treated with: (1) without organic amendments; (2) 30 Mg ha-1 Chicken manure (CM); (3) 30 Mg
ha-1
organic city waste compost (CW); (4) 15 Mg ha-1 CM biochar; and (4) 15 Mg ha-1 CW biochar. The
results show that application of biochar could impede the transformation of N-NH4 to N-NO3. After 28 days of
incubation, there was 60 mg kg-1 N-NH4 (CM biochar) and 52 mg kg-1 (CW biochar), compare to 40 mg kg-1
N-NH4 (CM) and 12 mg kg-1 N-NH4 (untreated soil).In addition to the high CEC, this high N-NH4 in biochar
treated soil one of the mechanism by which biochar decrease nitrogen loss due to leaching. The nitrogen loss
due to leaching from biochar treated soil was 470 – 510 mg, whereas that of from untreated soil 641 mg.
Keywords: organic amendment, organic manure, poultry litter, leaching