| Summary: | 碩士 === 國立臺灣大學 === 農業化學研究所 === 93 === The objectives of this study were to examine the effects of fertilization management on the rhizosphere soil enzyme activities（b-glucosidase, b-glucosaminidase, arylamidase, urease, acid phosphatase, arylsulfatase and dehydrogenase related to C, N, P, and S cycles）and bacterial community structure under a maize-rice crop rotation system in an experimental field in Taiwan Agricultural Research Institute. The maize-rice rotational cropping system was initiated in the experimental field since August 1995. The experimental design was a randomized complete block design with four replications and seven fertilization managements, including：Check, Chemical N, Hog manure compost, Compost + Chemical 1/3N, Compost + Chemical 2/3N, Green manure + Chemical 1/3N, and Peat + Chemical 1/3N.
The results showed that Hog manure compost, Compost + Chemical 1/3N, and Compost + Chemical 2/3N managements significantly increased the activities of rhizosphere soil enzymes in this study（P＜0.05）. Among the maize crop growing stages, the activities of urease, acid phosphatase, and dehydrogenase in rhizosphere soils were highest in the knee-high stage, that of arylsulfatase was highest in the tasseling stage, and those of b-glucosidase, b-glucosaminidase, and arylamidase in were highest in the harvesting stage; among the rice crop growing stages, the activities of urease, b-glucosaminidase, and arylamidase in rhizosphere soils were highest in the active tasseling stage, that of b-glucosidase was highest in the heading stage, and those of arylsulfatase and dehydrogenase in rhizosphere soils were highest in the harvesting stage. In general, those seven rhizosphere soil enzyme activities significantly correlated with organic matter, ammonium-nitrogen, nitrate-nitrogen, inorganic nitrogen, available phosphate, water soluble- phosphate, and microbial biomass carbon content in maize field（P＜0.05）, and significantly correlated with organic matter, ammonium nitrogen, nitrate nitrogen, inorganic nitrogen, available phosphate, water soluble phosphate, sulfate and microbial biomass carbon and nitrogen content in rice field（P＜0.05）. The results of random amplified polymorphic DNA（RAPD）analysis showed that the structure of rhizosphere soil bacterial community on Compost + Chemical 2/3N management was significantly different from the other six managements（0 ﹪similarity）, and there was no significant difference among those of six managements（67-100 ﹪similarity）.
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