Taking Hainan Eucalyptus plantation as the research object with 4 other kinds of plantations or natural forest as reference plots, the effects of different forest land types on soil nutrient contents were analyzed, an...Taking Hainan Eucalyptus plantation as the research object with 4 other kinds of plantations or natural forest as reference plots, the effects of different forest land types on soil nutrient contents were analyzed, and the differences of soil properties were discussed. The results showed that: (1) Eucalyptus plantations were relatively helpful to reduce soil bulk density and enhance the stability of water-stable aggregates;(2) Eucalyptus plantations can improve the content of soil organic matter;(3) Soil pH showed an overall acidi fication trend under forest land conditions in Hainan;total nitrogen and alkali-hydrolyzed nitrogen content of Eucalyptus plantations showed a downward trend with the deepening of soil layer;total phosphorus and available phosphorus content showed a downward trend, while organic matter, total potassium and available K showed an upward trend. (4) The contents of total phosphorus and available phosphorus in the soil of Eucalyptus plantations of different ages did not change significantly, whereas the contents of other nutrients decreased gradually with the increase of soil depth.展开更多
The objective of this study was to evaluate the chemical and physical attributes of soil, and the productivity of Eucalyptus cultivated in monoculture and silvopastoral systems. The experiment started in 2009 and eval...The objective of this study was to evaluate the chemical and physical attributes of soil, and the productivity of Eucalyptus cultivated in monoculture and silvopastoral systems. The experiment started in 2009 and evaluated the following four systems： native vegetation system （Cerrado）, a degraded pasture, a Eucalyptus urograndis monoculture （E. urophylla x E. grandis） and a silvopastoral system （E. urograndis combined with Brachiaria brizantha cv. ＂Marandu＂）. The experimental design used was completely randomized. In each system, four soil samples were collected from the 0-20 cm depth layer, and the chemical and physical attributes of the soil were evaluated. The diameters of all Eucalyptus trees at 1.30 m above the ground as well as the total height were measured. Subsequently, the trees dimensions were measured and their individual volumes obtained by applying the Smalian formula. The correlation between the parameters for Eucalyptus production and soil attributes was established using the Pearson＇s correlation coefficient method. The planting of Eucalyptus in monoculture and silvopastoral systems contributed to the improvement of the soil＇s chemical and physical attributes, which indicates the potential of these systems for recovery of degraded pastures. The silvopastoral system yielded the highest average volume of wood per tree （0.2228 m^3）, with a productivity of 111.4 m^3/ha. The Eucalyptus monoculture yielded 0.1895 m^3 per tree and 315.71 m^3/ha due to the higher density of the crop. The growth and productivity of Eucalyptus showed highly correlation with the soil attributes, thus suggesting that well-managed crops are an indicator of the soil quality recovery.展开更多
文摘Taking Hainan Eucalyptus plantation as the research object with 4 other kinds of plantations or natural forest as reference plots, the effects of different forest land types on soil nutrient contents were analyzed, and the differences of soil properties were discussed. The results showed that: (1) Eucalyptus plantations were relatively helpful to reduce soil bulk density and enhance the stability of water-stable aggregates;(2) Eucalyptus plantations can improve the content of soil organic matter;(3) Soil pH showed an overall acidi fication trend under forest land conditions in Hainan;total nitrogen and alkali-hydrolyzed nitrogen content of Eucalyptus plantations showed a downward trend with the deepening of soil layer;total phosphorus and available phosphorus content showed a downward trend, while organic matter, total potassium and available K showed an upward trend. (4) The contents of total phosphorus and available phosphorus in the soil of Eucalyptus plantations of different ages did not change significantly, whereas the contents of other nutrients decreased gradually with the increase of soil depth.
文摘The objective of this study was to evaluate the chemical and physical attributes of soil, and the productivity of Eucalyptus cultivated in monoculture and silvopastoral systems. The experiment started in 2009 and evaluated the following four systems： native vegetation system （Cerrado）, a degraded pasture, a Eucalyptus urograndis monoculture （E. urophylla x E. grandis） and a silvopastoral system （E. urograndis combined with Brachiaria brizantha cv. ＂Marandu＂）. The experimental design used was completely randomized. In each system, four soil samples were collected from the 0-20 cm depth layer, and the chemical and physical attributes of the soil were evaluated. The diameters of all Eucalyptus trees at 1.30 m above the ground as well as the total height were measured. Subsequently, the trees dimensions were measured and their individual volumes obtained by applying the Smalian formula. The correlation between the parameters for Eucalyptus production and soil attributes was established using the Pearson＇s correlation coefficient method. The planting of Eucalyptus in monoculture and silvopastoral systems contributed to the improvement of the soil＇s chemical and physical attributes, which indicates the potential of these systems for recovery of degraded pastures. The silvopastoral system yielded the highest average volume of wood per tree （0.2228 m^3）, with a productivity of 111.4 m^3/ha. The Eucalyptus monoculture yielded 0.1895 m^3 per tree and 315.71 m^3/ha due to the higher density of the crop. The growth and productivity of Eucalyptus showed highly correlation with the soil attributes, thus suggesting that well-managed crops are an indicator of the soil quality recovery.
