秸秆还田方式对棕壤性状和磷组分的影响

Effects of straw return methods on traits and phosphorus fractions of brown soils

为遏制棕壤沙化,提升棕壤质量,实现秸秆循环利用,选择辽宁地区典型沙化棕壤实施秸秆粉碎还田、生物炭还田、牛粪还田,以探究这3种秸秆还田方式对棕壤性状和磷组分的影响。结果表明,秸秆粉碎还田和牛粪还田后土壤容重显著减小,生物炭还田后土壤pH显著降低,牛粪还田能显著增加土壤水分含量和中性磷酸酶活性(soil neutral phosphatase activity,SNP)。秸秆粉碎还田对土壤磷组分影响不显著,生物炭还田使土壤总磷(total phosphorus,TP)和微生物生物量磷(microbial biomass phosphorus,MBP)分别显著增加了23%和50%,牛粪还田使土壤TP、有效磷(available phosphorus,AP)和MBP分别显著增加了31%,98%和57%。土壤AP与TP,MBP线性正相关,MBP与TP线性正相关。土壤水分含量和pH与磷组分相关关系显著。秸秆还田方式对土壤TP的方差解释量最大,土壤水分含量对AP的方差解释量最大,而土壤pH对MBP的方差解释量最大。牛粪和生物炭还田是短期内改善土质和增加土壤磷肥力的有效手段,而秸秆粉碎还田则可能是长期处理秸秆、改善土质的重要手段。

To prevent the desertification of brown soil,improve its quality,and realize straw recycling,a field experiment was carried out in the desertified brown soils in Liaoning to explore the effects of three straw return methods(i.e.,crushed straw,biochar,and cow manure)on soil traits and phosphorus fractions.The results show that the soil bulk density under crushed straw and cattle manure treatments is significantly lower than that in the control.Biochar treatment significantly decreases soil pH.Cattle manure treatment significantly increases soil water content and neutral phosphatase activity relative to the control.Crushed straw treatment shows there is no significant effects on soil phosphorus fractions.Biochar treatment significantly increases soil total phosphorus(TP)and microbial biomass phosphorus(MBP)by 23%and 50%,respectively.Additionally,cattle manure treatment significantly increases soil TP,available phosphorus(AP)and MBP by 31%,98%and 57%,respectively.Soil AP is linearly positively related to TP and MBP,and MBP is linearly positively related to TP.Soil water content and pH are significantly correlated with soil P fractions.Straw return methods,soil water content and pH have explained the largest proportions of variance in soil TP,available phosphorus and MBP,respectively.Cattle manure and biochar treatments are effective means to improve soil quality and increase soil P fertility in the short term,while crushed straw treatment may be an important means to manage straw and improve soil quality in the long term.