Mineralization and Availability of Azolla and Cyanobacteria Biomass Nutrients in Rice Soil  

作　　者：Debjani Halder Shyamal Kheroar 

机构地区：[1]Department of Agricultural and Food Engineering, Indian Institute of Technology Kharagpur, West Midnapur, West Bengal721302, India [2]Regional Research & Technology Transfer Station, Orissa University of Agriculture and Technology, Semiliguda, Koraput,Odisha 763002, India

出　　处：《Journal of Agricultural Science and Technology(A)》2013年第10期782-789,共8页农业科学与技术（A）

摘　　要：Two sets of experiments were conducted to study the chemical composition, mineralization and availability of nutrients （particularly N） of Azolla biomass and cyanohacteria blooms in submerged rice soil. One set of experiment was conducted with Azolla without soil and the other with both Azolla and cyaobacteria with soil, in laboratory condition. Large samples were collected from the rice fields. The study shows that Azolla and cyanobacterial biomass contain good amounts of C, N, P and Ca. The chemical analysis of oxidizable C, total N, P and Ca showed that Azolla biomass contain 20.7% oxidizable C, which is higher than the cyanobacterial biomass （9.18%）. The N content in Azolla biomass was found to be 4.32%, than that of cyanobacterial biomass, i.e., 2.57%, however, P and Ca contents were also found to be higher in Azolla averaging to 124.83 ppm and 345.3 mg/100 g, respectively than cyanobacteria. The leachate analysis revealed that Azolla biomass release about 39.18% to 64.48% oxidizable C and about 19.23% to 33% N after 45 days of incorporation of soil dilution. Incorporation of Azolla and cyanobacterial biomass N@ 100 kg/ha significantly improved the oxidizable organic C, total as well as available N content in soil up to 75 days of incubation. Due to the incorporation of Azolla in soil, oxidizable organic C increased 25.51%, total N 4.10% and available N 47.65%. Almost similar trend of increase was also observed with the incorporation of cyanobacterial blooms.

关 键 词：AZOLLA CYANOBACTERIA MINERALIZATION organic carbon rice. 

分 类 号：S154.3[农业科学—土壤学] X524[农业科学—农业基础科学]