The Research On Matching Technology Of High-yield Cultivation For Eucalyptus

To explore the suitable technology of high-yield cultivation for Eucalyptus and promote the sustainable and healthy development for the state-owned Weidu forest farm of Guangxi, the effects on growth of Eucalyptus made by different clones, different planting densities, different methods of topdressing and tending were studied. The results were as follows:1. The afforestation experiments of different clones showed that E.urophylla×E.camaldulensis, E.grandis×E.urophylla Guanglin No.11, E.grandis×E.urophylla Guanglin No.9and E.urophylla×E.grandis DH32-28grew better than E.urophylla×E.grandis DH32-29and E.Thailand K7. Their per unit area (667m2) stand volume at the fouth year were12.0m3、11.7m3、11.6m3、11.6m3、9.5m3、5.1m3respectively.2. The afforestation experiments of different densities showed that excessive afforesting densities went against for the normal growth and accumulation of volume of Eucalyptus. The experiments also showed that the decrease of afforesting densities were favourable for the accumulation of individual volume to a certain extent, but too low afforesting densities went against for the accumulation of volume per unit area. Among the afforestation experiments of different densities volume per unit area (667m2) at the fouth year of the third treatment (spacing in the rows and spacing between rows of2m×3m) was the highest (11.99m3) and volume per unit area of the first treatment (spacing in the rows and spacing between rows of2m×2m) was the lowest (9.55m3).3. The afforestation experiments of different topdressing methods showed that fertilizer requirement of the young and middle-aged Eucalyptus increased with the stand age. Excessive fertilizer caused damage easily and went against for the normal growth and preservation rate of young-aged Eucalyptus. But quantities of topdressing of the middle-aged Eucalyptus should be increased with its fertilizer requirement.4. The afforestation experiments of different tending measures showed that adopting only the method of spraying herbicide caused damage easily and went against for the normal growth and preservation rate of Eucalyptus at the first year. The experiments also showed that the effect of tending on Eucalyptus by adopting the method of combinating grass cutting, irrigation with spraying herbicide was the best among the several tending measures, but it also cost the most. Under the circumstance of shortage of the resource of migrant workers, it was difficult to afforest by adopting the tending method of combinating grass cutting and irrigation with spraying herbicide.Therefore, the following conclusions could be made from the research by combinating benefit analyses with actual conditions of the state-owned Weidu forest farm of Guangxi.(1) E.grandis×E.urophylla Guanglin No.9was the best clone for large areas of afforestation.(2)111plants per mu (spacing in the rows and spacing between rows of2m×3m) was the best afforesting density for Eucalyptus.(3) Adopting the method of0.50kg per plant at the first year,0.75kg per plant once at the second year, and1.00kilogramme per plant once at the third year was the best topdressing scheme for Eucalyptus.(4)Adopting the method of grass cutting and irrigation twice at the first year (if conditions allowed, it could be conbinated with the tending methods of hole preparation and strip preparationz), combinating the method of grass cutting and irrigation with spraying herbicide once at the second year, spraying herbicide once at the third year was the best scheme for tending of Eucalyptus.