Study on Compound Management Techniques for Cultivating Big-diameter Timber Poplar Plantations in Typical Areas along the Yangtze River
In this paper,an analysis was made on the growth and economic benefits of 5 typical compound management modes for culti-vating big-diameter poplars in the cultivation period to select the best compound management mode for growing big-diameter poplars in suitable areas along the Yangtze River and provide reference for the big-diameter poplar cultivation and compound management strategy in these areas.The results showed that the DBH,tree height and per-unit-area volume of the poplars in the tested agroforestry compound management modes increased by 15.31%(YM)~20.92%(YYD),9.52%(YM)~11.31%(YY)and 45.66%(YM)~61.38%(YYD)respectively compared with those of the pure poplar plantation.The total incomes of the 6-year-old poplars in the intercropping compound management mode were all higher than those gained from pure poplar plantations with the total output value 2.78~4.47 times higher than that of the pure poplar plantations.The total income and total output value in the multiple-crop intercropping modes were all significantly higher than those in the single-crop intercropping mode,in which the 6-year-old poplar-oilseed rape-soybean intercropping mode(YYD)produced the highest total income of 11 905 yuan/667m2,followed by the poplar-wheat-soybean mode(YMD)with the total income of 11 599 yuan/667m2.From the highest to the lowest,the income from timber of the 6-year-old poplars in the 5 modes was YYD(7 244 yuan/667m2)>YMD(7 197 yuan/667m2)>YY(7 106.5 yuan/667m2)>YM(6 539.6 yuan/667m2)>YC(4 408.48 yuan/667m2).The poplar-oilseed rape-soybean intercropping mode(YYD)is the optimized mode promoting big-diam-eter poplar growth,increasing timber volume and having the highest economic benefits.
Areas along the Yangtze RiverBig-diameter poplarsAgroforestry compound managementOutput-input ratioBalance between income and expenditure