马尾松天然次生林施肥效应研究

Fertilizer Effects on the Plant Growth and Wood Proportion of Natural Secondary Forestry of Pinus massoniana

采用正交设计，对立地指数为12～14的23a生马尾松天然次生林不同肥种与配比施肥4a后的效果进行了系统研究．其主要结论是：（1）氮、磷、钾3种肥料对马尾松胸径、材积以及经济产量增长具有显著或极显著影响，其对胸径与经济产量影响效应主攻为磷肥〉钾肥〉氮肥，而对材积增长影响效应主次则为磷肥〉氮肥〉钾肥，并3种肥料对树高的影响中仅钾肥的影响达到极显著水平．而氮肥及磷肥的影响不明显．（2）磷肥对木材比重有显著影响，而氮肥和钾肥的影响不明显，施用磷肥将给木材比重带来一定的负面影响．而其影响的显著性程度以磷肥施用量300g／株为阀值．（3）对经济产量具有显著性影响的肥种有磷肥和钾肥，尤以磷肥的影响为最大．（4）肥种间交互作用明显，全营养配方施肥的效果明显优于单一肥种，在土壤较为贫瘠，磷、钾缺乏的林地进行氮、磷、钾全营养配方施肥具有明显的增产效应，与不施肥处理相比较，最优配方施肥单位面积材积与经济产量可提高104．4％和81．2%；在南方低山丘陵区红壤地地位指数为12～14的马尾松天然林最佳施肥配方为氮肥50g／株，磷肥300g／株，钾肥150g／株．（5）不同立地条件其施肥效果存在一定的差异．

Systematic research was done on measuring the effects of fertilizer application on different single fertilizer and different proportioning fertilizer 4 years after fertilization in the 23-year-old natural secondary forest of Pinus massoniana by orthogonal design method. The results show; （1）The obvious effects were an increase in the diameter breast height, volume and economic production of P. masoniana caused by the application of fertilizer N, P and K; the effects on the increase of diameter breast height and economy was P〉K〉N, the effect on the increase of volume was P〉N〉K and the effect on the increase of height was only K. （2）The effect on the wood proportion by P was obvious; P brings a negative effect to the wood proportion and the most obvious effect is fertilizer 300 g per plant. （3）The effects on the economic production were P and K, especially P. （4）The effects on the interaction of fertilizer with N, P and K and a complete fertilization was more effective than the incomplete practice of single fertilizer. Applying the complete fertilization resulted in the best fertilizer method with the complete fertilization; compared with no fertilization the effects were an increase of 104.4% in volume and 81.2 % in economic production. The best fertilization for P. masoniana planted in the red soil in index 12-14 of the hills in southern China was 50 g （N）, 300 g （P） and 150 g （K） per plant, 5）Difference existed on fertilization of different site conditions.