Soil aggregate stability and nutrient content of Pinus massoniana plantation at different age groups in fragile ecological area of Guizhou
[Objective]The characteristics and relationship of soil aggregate distribution,stability and nutrient content were analyzed in Pinus massoniana plantation of age groups in fragile ecological area of Guizhou.[Method]3 middle-age forest,5 near-mature forest and 3 over-mature forest plots were set up in Fenggang county,Zunyi city,Guizhou province.Soil aggregates of different particle sizes were obtained by wet sieve method,and their mass fraction,mean mass diameter(MWD),geometric mean diameter(GMD)and soil organic carbon(SOC),total nitrogen(TN)and total phosphorus(TP)contents were calculated.[Result]1)The soil aggregate mass fraction reduced with the decrease of particle size in P.massoniana plantation of different age groups(P＜0.05),while MWD and GMD were not significantly different among 3 age groups(P＞0.05).2)With the increase of age group of P.massoniana plantation,SOC content of soil aggregates decreased first and then increased(P＜0.05).TN content gradually accumulated,and the TN content in near-mature forest and over-mature forest was significantly higher than that of middle-age forest(P＜0.05).TP content decreased gradually,and the TP content in middle-age forest and was significantly higher than that of near-mature forest and over-mature forest(P＜0.05);As the particle size of soil aggregates decreases,SOC content of aggregates increases gradually,while the TN content decreased gradually.The SOC contents in clay particles and microaggregates were significantly higher than that in macroaggregates(P＜0.05),and the TN content in macroaggregates was significantly higher than that in clay particles(P＜0.05).3)The SOC content in macroaggregates and TP content in microaggregates were significantly positively correlated with the macroaggregates distribution,clay particle distribution,MWD and GMD(P＜0.05);The SOC content of microaggregates was negatively correlated with the macroaggregates distribution,clay particle distribution,MWD and GMD(P＜0.05).[Conclusion]The change of age groups of P.massoniana plantation affected the distribution of soil aggregates and the changes of aggregate nutrients,and there was a significant correlation between aggregate nutrients and the distribution and stability of aggregates.The basic data of aggregate distribution,stability and nutrients of P.massoniana plantation can be obtained,which is of great significance for evaluation of soil structure and erosion resistance and forest management of the plantation at fragile ecological area of Guizhou.
NETL
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万方数据
