Characteristics of seasonal changes in soil carbon and nitrogen nutrients of different Phyllostachys pubescens stands

Key words: 
• pedology /
• Phylloslachys pubescens stands /
• soil total nitrogen /
• soil organic carbon /
• seasonal dynamics

Abstract: The characteristics of seasonal changes in the mass fractions of organic carbon and total nitrogen at three different layers of soil in different Phyllostachys pubescens stands were studied by the orientation research method . The results showed that the mass fractions of soil organic carbon (12.9 -38.9 gkg-1)in the reclaimed pure Phyllostachys pubescens stands in autumn and winter were higher than in spring and summer .The mass fractions of soil organic carbon (7.5 -31.2 gkg-1)in the non-reclaimed pure Phyllostachys pubescens stands in spring and summer were higher than in autumn and winter .The mass fraction of soil organic carbon (7.5 -40.2 gkg-1)in the Schima superba stands was highest in winter and lowest in spring , which was different from that in the pure Phyllostachys pubescens stands .The mass fraction of soil total nitrogen (0.8 -2.4 g kg-1)in reclaimed pure Phyllostachys pubescens stands was highest in summer and lowest in spring , that (1.3 -3.0 gkg-1)in the nonreclaimed pure Phyllostachys pubescens stands was highest in spring and lowest in autumn and that (0.9 -3.2 gkg-1)in Schima superba stands was highest in summer and lowest in autumn .The C N ratio in the reclaimed pure Phyllostachys pubescens stands was between 8.49 -46.03 , that in the non-reclaimed pure Phyllostachys pubescens stands was between 5.84 -11.99 , that in the Schima superba stands was between 3.43 -15.02 .The results of variance analysis showed that the mass fractions of soil total nitrogen were not significantly different in different stands , significantly different between spring and autumn , not significantly different between autumn and winter , much significantly different between the layers of 0 -10 cm and 30 -50 cm , significantly different between the layers of 0 -10 cm and 10 -30 cm.The mass fractions of soil organic carbon were not significantly different in different seasons and different stands , much significantly different among the layers of 0 -10 cm, 10 -30 cm and 30 -50 cm .Therefore , the mass fractions of soil carbon and nitrogen in different stands were comparatively different in different seasons and different soil layers .[ Ch , 4 tab .16 ref .]