不同施肥对雷州半岛桉树林地土壤培肥效应研究

本文研究了雷州半岛两种主要类型砖红壤有机肥与无机肥配施对桉树土壤养分特征和土壤培肥效应。结果表明:在雷州半岛低地力的土壤中种植桉树时,浅海沉积物发育的砖红壤有机质有所提高,而玄武岩砖红壤有机质下降;土壤有机质含量与林木生长量相关性为极显著水平,与施肥量的相关性较低,未达到显著水平。随施有机肥数量的增加,有机质呈上升趋势。施用滤泥1.5～2.5 kg.株-1时,土壤有机质比单施无机肥提高0.02%～0.21%,比不施肥提高0.07%～0.26%。经施肥后5a测定,施有机肥处理容重比施无机肥的降低0.01%～0.22%,总孔隙度比施无机肥的提高0.1%～7.1%,说明施用有机肥改良砖红壤物理特性。因此,两种类型砖红壤中有机肥施用对桉树土壤肥力具有极显著培肥效应。

Effects of Different Fertilizers on Soil Fertility for Eucalypt Plantations in Leizhou Peninsula

This study examined the effect of organic fertilizer and inorganic fertilizer on soil nutrients and fertili- ty levels. The results showed that in the low fertility soils of Leizhou Peninsula, organic matter content in basalt - latosol soils increased but that in other latosol soils （developed from neritic sediments ） declined when Euca/yptus was planted. Significant correlations between soil organic matter content and the growth of Euca/yp- tus were found, but growth was not significantly influenced by the different levels of the fertili~,ers applied in this study. As the ar~unt of filtered mud applied increased from 1.5 to 2.5 kg ~ plant -1, soil organic matter content increased from 0.02% to 0.21% relative to that with a single inorganic fertilizer, and by 0.07% to 0.26% relative to that with no fertilizer. Five years after application of the fertiliTers, soil bulk density de- creased by 0.01% to 0.22% for the organic fertilizer relative to the inorganic fertilizer; total porosity of the former was increased by 0.1% to 7.1% compared to that of the latter. Overall the results showed that organ- ic fertilizer can improve physical properties of latosol soils and has a significant effect on fertility levels of such soils under eucalypt plantations.