栽培油茶可增加林农收入,还能促进地方经济发展.油茶栽培受多方面因素影响,若未能良好应用高产栽培技术,会严重降低油茶种植效益.因此,油茶种植过程中,相关人员应掌握高产种植技术,注重各环节工作的科学落实,以实现油茶高产目标.文章对广西国有高峰林场实施的油茶高产种植策略进行了分析,以供参考.

Response to nitrogen from different kinds of Eucalyptus seedlings were studied for screening Eucalyptus varieties with high nitrogen efficiency.Greenhouse experiments in Guangxi Academy of Agricultural Sciences were carried out to understand the response under two nitrogen levels in 2009.The results showed:(i)Under normal nitrogen,there were significant variations in total N uptake(TNU),N uptake efficiency(NUE),N physiological utilization efficiency(NPE),and N use efficiency(NE) as well among the five Eucalyptus genotypes.Any of them could be considered as referential index to select high NE Eucalyptus genotype.The differences of NE were determined principally by TNU and NUE.(ii)The tested Eucalyptus could be classified into three different types based on NE: urophylla×camaldulensis belonged to HH type(high N use efficiency at high nitrogen level);No.4 Guanglin E.urophylla and E.urophylla×E.grandis belonged to HM type(mid N use efficiency at high nitrogen level);No.12 Guanglin E.grandis ×E.urophylla and No.9 Guanglin E.grandis×E.urophylla belonged to HL type(low N use efficiency at high nitrogen level).The basis for breeding the high NE Eucalyptus variety at low N level or at both low and high N level conditions could be provided by the Eucalyptus of HH type or HL type.(iii)Dry plant weight,dry root weight,dry branch and leaf weight,TNU,NUE,and nitrogen responsiveness were significantly correlative with NE,so all of them could be regarded as the indexes to screen the variety with high NE.