赤桉、细叶桉和巨桉幼林施磷量的确定

The Potential Minimum Phosphorus Fertilizing for Eucalyptus camaldulensis,E. grandis and E. tereticornis

在广东省阳西县 ,对赤桉、巨桉和细叶桉进行 10个 P处理水平的施肥试验 ,结果表明 :造林后 1～ 6 4个月期间 8次测定的树高和 9～ 6 4月期间 6次测定的胸径在 10个 P处理水平间和 3个树种间均有显著或极显著差异 ,P肥对促进 3种桉树树高和胸径生长的肥效明显 ,3个参试树种对P肥的需求也有明显差异 ,表现为 6～ 2 4个月期间观测的生长指标存在树种与 P肥的交互效应。各树种肥效明显的高峰区域的开始和持续时间也不同 ,为筛选施 P量创造了条件 ,讨论了参试树种造林时必须的施

A fertilizing experiment was established in March 1989,at Yangxi,Guangdong,China. A randomised block split plot design was employed in which 10 phosphorus rates (0,5,10,15,25,35,50,100,150,200 kg(P)·hm -2 as superphosphate in sub plots randomised within main plots which represented 3 Eucalyptus species, Eucalyptus camaldulensis,E. grandis and E. tereticornis . The tree heights were measured at 1,3,6,9,12,21,24,64 months after planting,and DBH at 9,12,21,24,40 and 64 months. The results showed that the tree heights from 1 to 64 months and DBH from 9 to 64 months were significant differences ( P <0.01 or P < 0.05 ) between unfertilizing and 9 P treatments,and between 3 Eucalyptus species. Phosphorus fertilizer can clearly improve the growth of tree heights and DBH ,but the improvement was different in phosphorus needs among the 3 tree species,that is ,tree heights and DBH measured from 6 to 64 months were significant interaction effect between tree species and phosphorus treatment,and the starting and end of the high effectiveness periods were differences between 3 species. It was suggested that potential lower quantity of phosphorus fertilizer when planting in field,respectively 50～100 kg(P)·hm -2 for E. camaldulensis and E. grandis ,and 25～100 kg(P)·hm -2 for E. tereticornis.