title: Effects of slow-release urea fertilizers on urease activity, microbial biomass, and nematode communities in an aquic brown soil.
abstract: A field experiment was carried out at the Shenyang Experimental Station of Ecology (CAS) in order to study the effects of slow-release urea fertilizers high polymer-coated urea (SRU1), SRU1 mixed with dicyandiamide DCD (SRU2), and SRU1 mixed with calcium carbide CaC2 (SRU3) on urease activity, microbial biomass C and N, and nematode communities in an aquic brown soil during the maize growth period. The results demonstrated that the application of slow-release urea fertilizers inhibits soil urease activity and increases the soil NH4+-N content. Soil available N increment could promote its immobilization by microorganisms. Determination of soil microbial biomass N indicated that a combined application of coated urea and nitrification inhibitors increased the soil active N pool. The population of predators/omnivores indicated that treatment with SRU2 could provide enough soil NH4+-N to promote maize growth and increased the food resource for the soil fauna compared with the other treatments.
authors.affiliation: Key Laboratory of Terrestrial Ecological Process, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China.
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Jiao
authors.forename: Wenju
authors.initials: W
authors.lastname: Liang
authors.forename: Lijun
authors.initials: L
authors.lastname: Chen
authors.forename: Haijun
authors.initials: H
authors.lastname: Zhang
authors.forename: Qi
authors.initials: Q
authors.lastname: Li
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Dazhong
authors.initials: D
authors.lastname: Wen
mesh_terms: D000114:Acetylene / Q000031:analogs & derivatives / Q000737:chemistry / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D018533:Biomass; D005308:Fertilizers / Q000032:analysis; D006146:Guanidines / Q000737:chemistry / Q000494:pharmacology; D009348:Nematoda / Q000187:drug effects* / Q000254:growth & development; D009566:Nitrates / Q000032:analysis; D017672:Nitrogen Compounds / Q000032:analysis; D000644:Quaternary Ammonium Compounds / Q000032:analysis; D012987:Soil / Q000032:analysis* / Q000469:parasitology; D012988:Soil Microbiology; D013997:Time Factors; D014508:Urea / Q000737:chemistry / Q000494:pharmacology*; D014510:Urease / Q000378:metabolism*; D003313:Zea mays / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism
chemical_list: D005308:Fertilizers; D006146:Guanidines; D009566:Nitrates; D017672:Nitrogen Compounds; D000644:Quaternary Ammonium Compounds; D012987:Soil; C006873:calcium carbide; D014508:Urea; D014510:Urease; C004711:dicyandiamido; D000114:Acetylene