Stoichiometric Characteristics of C,N and P in Soil Aggregates in Eucalypt Plantations with Different Successive Rotations
In order to explore effects of different successive rotations on soil aggregates and soil stoichiometric characteristics in eucalypt plantations,taking the first to third successive rotations of eucalypt plantations in Guangxi as research objects,distributions,stabilities,contents and stocks of organic carbon(SOC),total nitro-gen(TN),total phosphorus(TP)in soil aggregates and their stoichiometric characteristics in 0-20 and 20-40 cm soil layers were investigated.Results showed that in eucalypt plantations with different successive rotations,mass percentages of soil aggregates with>2 mm particle size were the highest;contents of SOC,TN and TP were higher in soil aggregates with 0.25-1 and<0.25 mm particle sizes;stocks of SOC,TN and TP were the highest in soil aggregates with>2 mm particle size.In 0-20 and 20-40 cm soil layers,with increase of succes-sive rotations,mass percentages of soil aggregates with>2 and>1-2 mm particle sizes decreased;mass percent-ages of soil aggregates with 0.25-1 and<0.25 mm particle sizes increased;MWD and GMD of soil aggregates decreased,and D increased;contents of SOC,TN and TP in whole soils and soil aggregates with different parti-cle sizes decreased;stocks of SOC,TN and TP in whole soils decreased;most of stocks of SOC,TN and TP in soil aggregates with>2,>1-2 and 0.25-1 mm particle sizes showed decreasing trends,while stocks of SOC,TN and TP in soil aggregates with<0.25 mm particle size showed increasing trend.In eucalypt plantations,soil C decomposition and mineralisation rates were faster,soil P effectiveness was higher,and soils were N-limited.Results of RDA and PLS-SEM showed that soil aggregate stability characteristics had the greatest positive ef-fects on stocks of SOC,TN and TP in soil aggregates,and successive rotations had the greatest negative effects on stocks of SOC,TN and TP in soil aggregates.
soil aggregatesuccessive rotationstoichiometry of C,N and Peucalypt
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