施肥对热带雨林下种植砂仁土壤氮矿化和硝化作用的影响

Effects of Fertilization on Mineralization and Nitrification of Nitrogen in Soil Grown Amomum Under Tropical Rainforest

采用封顶埋管法(Close-TopIncubation)研究了施肥后西双版纳热带雨林下种植砂仁土壤的氮素净氨化、净硝化和净矿化速率。结果表明,种植砂仁的热带雨林土壤有机氮的净氨化、硝化和矿化速率明显受外来无机氮的影响,施入铵态氮肥后,土壤中的氨化速率明显提高(P<0.01),由对照土壤的-0.66(mg·kg-1·30d-1)增加至施肥处理土壤的1.65(mg·kg-1·30d-1),但硝化速率和矿化速率却显著降低(P<0.01),分别由对照土壤的6.79(mg·kg-1·30d-1)和6.13(mg·kg-1·30d-1)减少至施肥处理土壤的2.60(mg·kg-1·30d-1)和4.25(mg·kg-1·30d-1),导致了土壤中NH4+-N的积累。

The effects of fertilization on rates of nitrogen ammonification,mineralization and nitrification were s tudied in the soil grown Amomum under tropical rainforest in Xishuanbanna using close -top Incubation.The results of the study showed that effects of fertilization were significant (P<0.01)to rates of nitrogen magnification,mineralization and nitrification.Rate of ammonification was added significantly(P<0.01)from0.66mg ·kg -1 ·30d -1 in control soil to 1.65mg ·kg -1 ·30d -1 in the treatment soil.But rates of nitrogen nitrification and mineralization were decreased s ignificantly(P<0.01)from6.79(mg ·kg -1 ·30d -1 )and6.13(mg ·kg -1 ·30d -1 )in control soil to 2.60mg ·kg -1 ·30d -1 and 4.25mg ·kg -1 ·30d -1 in the treatment soil respec-tively,leading toNH 4+ -N accumulation in the soil.