Roots of corn (Zea mays L.) and wheat (
Triticum aestivm L.) grown in a long-term fixed
fertilization field of Laiyang Agricultural
College were collected in September 2003 and May 2004, respectively. The mycorrhizal colonization status of the root in different treatments was determined. Results showed that the long-term nitrogen (N)
fertilization treatment significantly reduced mycorrhizal colonization percentage (MCP), arbuscule colonization percentage (ACP), number of vesicle (NV) and entry points (NE) per mm root length. The MCP of wheat treated with low N was higher than that treated with high N, while ACP of corn treated with high N was lower than that treated with low N. The MCP, ACP, NV,and NE of the plants treated with long-term fixed manure fertilization, especially high manure fertilization were significantly reduced. Manure mixed with N fertilizer also significantly reduced MCP,ACP, NV,and NE. Except NV of wheat, the long-term fixed NPK fertilization decreased MCP,ACP, NV,and NE on corn and wheat roots. In NP treatment, the ACP on corn and MCP and ACP on wheat showed the lowest. In addition, the MCP of corn treated with low manure mixed with N fertilization, and NPK was higher than that of wheat. It is concluded that the development of mycorrhizas andtheir structures were influenced with different fertilization regimes. There are interactions between manure and nitrogen fertilization in influencing AM fungal colonization.