尾叶桉MLA无性系林分不同施肥处理经济效益分析

对雷州林业局7种施肥处理的尾叶桉MLA无性系7年生与3年生林分进行经济效益分析，结果表明：最佳处理6(P300g/株 K300g/株 N150g/株)7年生时年均利润1528．1元41m2，比处理7(常规施肥，滤泥5000g/株 P250g/株 K100g/株 N100g/株，年均利润1452．6hm2)提高5．2％，比对照(不施肥，年均利润630．3元/hm^2)提高142．4％；3年生时处理6的年均利润为1605．5元/hm2，比处理7(年均利润1406．8hm2)提高14．1％，比对照(年均利润408．3元/hm2)提高293．2％；处理6的年均利润3年生时采伐比7年生时采伐提高5．1％；处理6和处理7在7年生时采伐，投资回收期均为10．3年，在3年生时采伐分别为8.0年与8．3年，3年生时采伐比7年生时采伐的投资回收期分别缩短2．3年与2．0年。

ECONOMIC BENEFIT ANALYSIS OF MLA CLONE, EUCALYPTUS UROPHYLLA FOREST ON DIFFERENT FERTILIZER LEVEL

The Experimental forest of MLA Eucalyptus urophylla clone was planted at Leizhou Forestry Bureau in 1993 under 7 fertilizer level. The forest was measured at 3 and 7 years old. Its economic benefit analysis results show that: The best treatment which have the most economic benefit are treatment 6 (P 300 g/tree + K 300 g/tree + N 150 g/tree), its annual profit are 1528.1 yuan/hm 2 at 3 years old and 1605.5 yuan/hm 2 at 7 years old, which increased 5.2% and 14.1% than that of treatment 7, and increased 142.4% and 293.2% than that of treatment 1 (not fertilize). If the rotation are 3 years, the payout period of treatment 6 and treatment 7 are 8.0 and 8.3 years, while its all are 10.3 years if the rotation are 7 years. So if the rotation are 5 years, the forest could have the more benefit and the payout period could reduce 2.3 and 2.0 years for treatment 6 and 7 respectively.