桉树间种菠萝对土壤性质和林木生长的影响

本文研究了雷林1号桉(Eucalyptus leizhou No.1)林地间种菠萝(Ananas comosus)对土壤性质、林地养分积累和林木生长的影响,并对间种的经济效益作了初步分析。结果表明,间种两年半后,林地枯落物保存量比对照区提高76％;间种区枯落物和菠萝植株所积累的N、P、K、Ca、Mg分別是对照区枯落物所积累的养分量的4.3、5.5、34.6、3.6和3.5倍;间种区桉树平均树高、胸径和每木蓄积量分別比对照区增大8.9％、13.4％和34.7％,蓄积量增加14.9m~3ha~(-1)。间种的直接经济效益已达4100元ha~(-1)。

EFFECTS OF INTERPLANTING PINEAPPLE UNDER EUCALYPTUS PLANTATION ON SOIL PROPERTIES AND TREE GROWTH

This paper deals with (1) the effects of interplanting pineapple(Ananas comosus) under eucalyptus (E. leizhou No. 1) plantation on soil properties, nutrition accumulation in forest land and tree growth, and (2) the primary analysis of economic benefits. The study was carried out on a sand loam latosol developed from shallow-sea deposit in Leizhou Peninsula. The results showed that the content of organic matter in interplanted soil increased by 26.2%; the concentration of total N, alkali-hydrolyzable N and available P increased by 16.0%, 9.2% and 138.2%, respectively; soil pH value rised by 0.17 unit. The litter mass maintained in interplanted stand was 76.0% higher than that in controlled stand. The amounts of N, P, K, Ca and Mg accumulated in litter and pineapple plants in interplanted stand were 4.3, 5.5, 34.6, 3.6 and 3.5 times as much as those accumulated in litter in controlled stand, respectively. After interplanting for 2.5 years, the mean height, mean BDH and mean volume of per tree were 8.9%, 13.4% and 34.7% higher than those in controlled one, respectively. Interplantation made storing increase by 14.9m~3 ha~(-1)(equals to 9.0 tones of stem wood except bark). After deducing the investment of interplanting, the increased wood and reaped pineapple fruit gave out 4100 yuan ha~(-1) net benefit. So it could be concluded that eucalyptus-pineapple interplantation in infertile latosol has obvious ecological benefit and marked economic benefit and is an effective way to maintain soil fertility and to make the infertile soil be utilizable forever.