板栗苗木叶片氮磷钾含量与生长量动态变化关系的研究

Studies on the Dynamic Changing Relationships between the Contents of Nitrogen,Phosphorus and Potassium and the Growth of Chestnut Seedling Leaves

对板栗ｌａ生苗叶内氮（Ｎ）、磷（Ｐ）、钾（Ｋ）含量和苗高，地径相对生长量随季节（月份）更替的动态变化规律及相互关系进行研究。结果表明，叶内Ｎ，Ｐ，Ｋ含量随季节（月份）更替呈有规律变化，三者含量均以５月中旬最高（５３．３６ｇ·ｋｇ￣（－１），１．４７ｇ·ｋｇ￣（－１），５．９３９．ｋｇ￣（－１）），至７月中旬降为最低值（１３．３１ｇ·ｋｇ￣（－１），０．４５ｇ·ｋｇ￣（－１），４．６５ｇ·ｋｇ￣（－１）），８月中旬Ｎ，Ｐ回升为２２．３６９．ｋｇ￣（－１）和１．２３ｇ·ｋｇ￣（－１），而Ｋ至９月中旬回升为５．５４ｇ·ｋｇ￣（－１），之后均呈下降趋势；苗高和地径相对生长量动态变化与Ｎ，Ｐ，Ｋ含量动态变化之间有明显的偶合性。测定苗木叶内Ｎ，Ｐ，Ｋ含量动态变化可为科学培育苗木提供依据。

This paper presents studies on the dynamic changing regularity with the replace-ment of seasons(months)and the mutual relationships between the contents of nitrogen,phosphorus and potassium in the leaves and the relative growth of the diumeter at foot andthe height of the one-year-old seedlings of chestnut.The results show that the contentsof nitrogen,phosphorus and potassium in the leaves change regularly with the repalcementof the seasons(months).The contents of the three elements reach the highest points in themiddle ten days of May,and decrease to their lowest points in the middie of July;the con-tents of nitrogen and phosphorus go up again to 23.36g· kg￣(-1) and 1.23g· kg￣(-1) respective-ly,in the middle ten days of August.while content of potassium rise again to 5.54g· kg￣(-1)in the middle ten days of September.Then the contents of the three elements are on the de-cline.The relative growth of the diameter at foot and the height of the seedlings changeswith the vicissitude of the contents of the three elements,The determination of the dynam-icchanging regularity of the contents of the three elements in the leaves can provide a sci-entific basis for cultivating seedlings.