关键词: 玉米, 产量潜力, N利用效率, 相关分析, 分层聚类分析

Abstract: The soil physical properties in eight artificial forest stands in Sout h China were measured, and the stands were clustered into four groups, based on their soil physical characters. The first group included Acacia mangium, Castano psis fissa-Pinus caribaea, Michelia macclurei-Schima superba, Schima superba, and Pinus elliottii stands. Their soil bulk density was smaller in upper layer t han in deeper layers, capillary porosity was medium or relatively small, non-ca pillary porosity was medium or relatively great, non-capillary porosity and tot al porosity were greater in upper layer than in deeper layers, moisture content was medium or relatively great and decreased or kept steady with increasing dept h, and capillary moisture content was medium or relatively small except for A. mangium stand. The second group was Tectona grandis stand. Its soil bulk d ensity in all layers was great and closed each other, capillary porosity and cap illary moisture content were relatively great, and non-capillary porosity and m oisture content were small. The third soil group was Taxodium distichum stand. Its soil moisture content in all layers was much greater than that of other stands, soil bulk density, capillary porosity, non-capillary porosity of upper and mid dle layers were medium, capillary moisture content in these layers was great, so il bulk density and non-capillary porosity in lower layer were great, whereas c apillary porosity and capillary moisture content in this layer were small. The f ourth group was Eucalypys urophylla stand. Its soil bulk density was greater in upp er layer than in deeper layers, capillary porosity and capillary moisture conten t in all layers were great, whereas non-capillary porosity and moisture content were small.

Key words: Zea mays, Grain yield potential, Nitrogen utilization efficiency, Correlation analysis, Hierarchical cluster analysis