湿地松苗木生长与红壤黄壤养分条件关系

湿地松土培试验结果表明,湿地松对磷素供应水平的反应最为敏感。其植物干物质重,针叶磷含量与土壤有效磷呈极显著的正相关,分布广泛的丘陵红壤和山地黄壤的磷素水平都极低,施磷对湿地松的高、径、根、叶的生长和干物质积累有极显著的促进作用。丘陵红壤也缺氮,干物质、针叶氮含量、叶绿素含量与土壤有效氮相关性极密切;由于湿地松生长受到氮磷交互效应和磷的限制作用的极深刻影响,缺磷红壤上单施氮肥肥效不显著,甚至负效应减产,氮肥效果只有在施磷的基础上才显示出来,合理的氮磷配合施用还能更好地发挥磷肥肥效,山地黄壤氮素较少富;单施氮肥无效单施磷肥效果显著,氮磷配合效果最好,钾肥在缺钾土壤上有一定作用,其主要功能是提高了湿地松抗病性;钙镁肥能提高湿地松针叶干物重,但对植株生长无明显影响,硼肥能消除湿地松顶枯病;红壤不缺锌,施锌肥显著抑制湿地松茎根和叶生长。

The Relationships between the Growth of Pinus Ellioitii Seedlings and Nutrient Levels of Red Earth and Yellow Earth

The results of the glasshouse experiment seedlings of Pinus elliottii Engelm cultivated in pots with typical red earth and yellow earth ( Halpuldu-lts) which distributed extensively in Southern China,showed that the seedlings were most sensitive to the supply of soil phosphorous. There were most significantly positive relations between P content in needles, dry weight of the seedlings and the available P levels of the soils. P was proved to be the first limitive growth factor in these soils The concetration of N and chlorophyll in the leaf and dry weight of the seedlings were closely related to the levels of available N in the red earth The reciprocal effects of N, P nutrients were confirmed. The growth responses of the seedlings wlen N, P added simultaneously were obviously greater than that of those wten N, P added separately alone. The output of single N fertilizer was limited, and even worse, less than that of the control. The height growth and the disease resistance of the seedlings on the red earth could be benefited by K fertilizer. Dieback disease could be prevented by using B fertilizer on both these soils The dry weight of needles was increased by adding Ca or Mg nutritions on red earth. The growth of height, root and needles were inhibited by adding Zn. The original Zn level in the red earth might have been already sufficent, or, the Zn must have been added excessively in this study.