退化红壤区人工林土壤的可溶性有机物、微生物生物量和酶活性

以江西省泰和县退化红壤区18年生马尾松纯林(Ⅰ)、马尾松 枫香 木荷混交林(Ⅱ)、木荷纯林(Ⅲ)和枫香纯林(Ⅳ)4种人工林林分为对象，并以自然恢复的无林荒草地为对照(CK)，研究其土壤的可溶性有机碳(SOC)、氮(SON)，微生物生物量碳(MBC)、氮(MBN)和土壤酶活性的变化.结果表明： 在0～10 cm土层，各林分类型的土壤SOC、SON含量分别为354～1007 mg·kg^-1和24～73 mg·kg^-1，MBC、MBN含量分别为203～488 mg·kg^-1和24～65 mg·kg^-1，脲酶和天门冬酰胺酶活性分别为95～133 mg·kg^-1·d^-1和58～113 mg·kg^-1·d^-1.不同林分类型之间SOC、SON含量为Ⅳ>CK > Ⅲ>Ⅰ>Ⅱ，MBC、MBN含量为CK>Ⅳ>Ⅲ>Ⅰ>Ⅱ，天门冬酰胺酶活性为Ⅳ>CK>Ⅲ>Ⅱ>Ⅰ，差异显著，而脲酶活性没有显著差异.随着土层加深，SOC、SON、MBC、MBN、脲酶及天门冬酰胺酶活性下降.在0～20 cm土层，SOC、SON、MBC、MBN、全碳和全氮两两之间达极显著相关.天门冬酰胺酶活性与SOC、SON、MBC、MBN、TSN、全碳、全氮极显著相关;而脲酶活性与SON、MBCMBN、TSN、全碳显著相关.

Soil soluble organic matter, microbial biomass, and enzyme activities in forest plantations in degraded red soil region of Jiangxi Province, China

Taking the adjacent 18-year-old pure Pinus massoniana pure forest (Ⅰ), P. massoniana, Liquidamber fomosana, and Schima superba mixed forest (Ⅱ), S. superba pure forest (Ⅲ), L. fomosana (Ⅳ) pure forest, and natural restoration fallow land (CK) in Taihe County of Jiangxi Province as test sites, a comparative study was made on their soil soluble organic carbon (SOC) and nitrogen (SON), soil microbial biomass C (MBC) and N (MBN), and soil urease and asparaginase activities. In 0-10 cm soil layer, the pool sizes of SOC, SON, MBC,and MBN at test sites ranged in 354-1007 mg·kg^-1, 24-73 mg·kg^-1, 203-488 mg·kg^-1, and 24-65 mg·kg^-1, and the soil urease and asparaginase activities were 95-133 mg·kg^-1·d^-1 and 58-113 mg·kg^-1·d^-1, respectively. There were significant differences in the pool sizes of SOC, SON, MBC, and MBN and the asparaginase activity among the test sites, but no significant difference was observed in the urease activity. The pool sizes of SOC and SON were in the order of Ⅳ> CK> Ⅲ>Ⅰ>Ⅱ, those of MBC and MBNwere in the order of CK>Ⅳ> Ⅲ >Ⅰ> Ⅱ, and asparaginase activity followed the order of Ⅳ>CK>Ⅲ>Ⅱ>Ⅰ.With the increase of soil depth, the pool sizes of SOC,SON, MBC, and MBN and the activities of soil asparaginase and urease decreased. In 0-20 cm soil layer, the SOC, SON, MBC, MBN, total C, and total N were highly correlated with each other, soil asparaginase activity was highly correlated with SOC, SON, TSN, total C, total N, MBC, and MBN, andsoil urease activity was highly correlated with SON, TSN, total C, MBC and MBN.