沼渣沼液混施对潮土团聚体结合有机碳的影响

Effect of biogas slurry and biogas residue combined application on aggregates associated organic carbon in fluvo-aquic soil

为实现畜禽粪污资源化利用和土壤肥力提升提供数据支撑,沼渣沼液混施对黄淮海平原潮土团聚体结合有机碳的影响成为重要研究课题.根据等碳量原则,设置不同沼渣沼液混施比例(100%沼渣,90%沼渣+10%沼液,80%沼渣+20%沼液,70%沼渣+30%沼液和60%沼渣+40%沼液)及对照不施肥处理进行6个月的盆栽试验,测定土壤团聚体组成及结合有机碳变化.结果表明:不同沼渣沼液混施比例对水稳性团聚体粒径组成和结合有机碳含量产生显著影响.相较于对照,各混施处理大团聚体质量组成比例(WR0.25)均有不同程度的提高,其中90%沼渣与10%沼液混施处理占比最大,为57.40%.此外,团聚体结合总有机碳含量随沼渣配施比例的增加呈现先增加后降低的趋势,其中80%沼渣与20%沼液混施处理下达到最高值,为16.5 g/kg.各配施处理均提高>0.25 mm粒径大团聚体结合有机碳的贡献率.因此,可通过80%~90%沼渣与10%~20%沼液混施促进潮土水稳性大团聚体的形成,提高团聚体稳定性和结合有机碳含量,从而达到改善土壤结构,促进土壤有机碳固持的目的.

Effect of biogas residue and biogas slurry combined application on soil aggregate associated organic carbon of fluvo-aquic soils in North China Plain was explored to provide scientific support for livestock and poultry manure resource utilization and soil fertility improvement.According to the principle of equal carbon content,different treatments(100% biogas residue;90% biogas residue+10% biogas slurry;80% biogas residue+20% biogas slurry;70% biogas residue+30% biogas slurry and 60% biogas residue+40% biogas slurry)and control without fertilization were designed by pot experiment for 6 months,to determine soil aggregate proportion and the dynamics of associated organic carbon.The results showed that biogas residue and biogas slurry combined application had significant effects on water-stable aggregate mass proportion and associated organic carbon.Compared with the control,the mass proportions of macro-aggregates(WR0.25)had been improved,of which 90% biogas residue and 10% biogas slurry combined application obtained the largest value,being 57.40%.The total organic carbon content within aggregates increased first and then decreased with the increase proportion of applied biogas residue.The highest was obtained in 80% biogas residue and 20% biogas slurry combined application treatment,being 16.5 g/kg.All of combined application treatments increased organic carbon contribution rate of macro-aggregates.Therefore,80%~90% biogas residue and 10%~20% biogas slurry combined application was proved to promote the formation of water-stable macro-aggregates,improve aggregate stability and associated organic carbon content,which was in favor of soil structure and soil organic carbon fixation.