Effects of One-year and Two-year Continuous Application of Biochar on the Stability and Availability of Phos-phorus in Paddy Soil
This study examined the influence of biochar application on soil phosphorus dynamics in a typical red paddy soil through a rice pot experiment.The experiment compared three treatments:no biochar application(CK),one-year bio-char application(B1),and two-year consecutive biochar application(B2).The concentrations and proportions of total phosphorus(TP),active P(PSOL,PM3),moderately stable P(PiOH,PoOH,PHC1),and highly stable P(PCL,POCL)were analyzed at different rice growth stages.Additionally,the responses of soil legacy P index(LGC),P saturation de-gree(DPS),and P adsorption capacity(SOR)to biochar addition were investigated.The results reveal that compared to the CK treatment,B1 application significantly reduced active P during the tillering stage but increased it during the maturi-ty stage.Moderately stable P increased significantly during the tillering stage in the B1 treatment.No significant changes were observed in highly stable P for all treatments(P＜0.05).In the B2 treatment,active P significantly increased during the heading and maturity stages,while moderately stable P increased during the tillering and maturity stages.The content of highly stable P remained unchanged,but its proportion decreased significantly by 18.8％and 27.8％during the heading and maturity stages,respectively.Both B1 and B2 treatments led to a significant increase in LGC and DPS,and the B1 treatment showed a significant increase in SOR during the heading stage.Overall,the addition of biochar significantly in-creased the content and proportion of active P and moderately stable P in paddy soil,decreased the proportion of highly stable P with low plant utilization,and enhanced soil legacy P and bioavailable P.These findings provide valuable insights for optimizing P management strategies in paddy fields.
biocharpaddy soilsoil phosphorous fractionationrisk of phosphorus loss
万方数据
维普
