摘要
为了探讨开垦对三江平原湿地土壤磷(P)形态含量及组成的影响,采用Hedley分级方法对比分析湿地开垦前后及垦后弃耕土壤不同形态P含量变化.结果表明,与湿地土壤相比,开垦3年(G3)时土壤总无机磷(TPi)上升达319·67mg·kg-1,其中活性和中等活性无机磷增幅最大(P<0·05),而总有机磷(TPo)下降313·28mg·kg-1.土壤无机磷含量随开垦年限增加而下降,耕作8年(G8)土壤中Resin-P、NaHCO3-Pi和NaOH-Pi分别仅为G3土壤的28·18%、42·87%和45·90%,耕作过程中土壤有机磷逐渐增加,但仅NaOH-Po升幅较大(P>0·05).弃耕后土壤中P的组成向湿地状况发展,弃耕后除Conc.HCl-Pi含量略有下降外,其他P形态均有所上升,但有机磷形态上升速度缓慢.开垦和弃耕过程中等活性P(NaOH浸提P)含量变幅最大;中等活性磷是三江平原湿地土壤P最主要的源和汇.
In order to discuss the influence of reclamation on wetland soil P, a modified Hedley P fractionation method was employed to compare the variations of P fractions between wetland soil, farmland and abandoned farmland in Sanjiang Plain, China. It can be found that the content of total inorganic P （TPi） increased 319.67 mg· kg^-1 after 3-year tillage （G3）, and the labile and secondary available Pi increased in a wider range （P〈0.05）, while the total organic P （TPo） decreased 313.28 mg.kg 1. The content of Pi decreased with tillage time. For 8-year tillage （G8） soil, the contents of Resin-P, NaHCO3-Pi and NaOH-Pi were only 28. 18%, 42.87% and 45.90% respectively, as much as those for G3. The content of Po increased with tillage time, but only NaOH-Po presented a relative larger increment （P〉0.05）. The status of soil P in abandoned farmland tended to approach that of wetland. The content of all the P fractions increased after abandoned, except Conc. HCl extracted fraction, however the Po increased in a comparatively lower speed. The content of secondary available P varied in the widest range, which is the main source and sink of P in the wetland of Sanjiang Plain
出处
《浙江大学学报（农业与生命科学版）》
CAS
CSCD
北大核心
2008年第3期315-321,共7页
Journal of Zhejiang University:Agriculture and Life Sciences
基金
中国科学院知识创新工程重要方向资助项目(KZCX2-YW-309)
国家自然科学基金资助项目(90211003)
关键词
开垦
湿地
P形态
tillage
freshwater wetlands
P fractions
