稳态营养原则在杉木、湿地松苗木施肥中的应用

按稳态矿质营养理论与技术原则，探索了１年生杉木、湿地松苗木的新型施肥技术。依“Ｓ”型曲线及有关计算公式，参照Ｉｎｇｅｓｔａｄ确定的针叶树幼苗最适营养物重量比例配制液体肥料，随浇水多次施入。每种苗木均设高、中、低、对照４种处理，施肥量比例为１：１／２：１／４：０，整个生长季中，以Ｎ元素计高处理杉苗每株（盆）施１１．９ｇ，松苗施１０．０ｇ。结果表明，按稳态营养原则改进施肥，能明显促进两种针叶树苗木当年新梢、地径的生长及于物质生产，其中杉木为突出，分析苗体营养状况和盆土养分含量变化，总结两种苗木营养特性，初步得到，在本试验条件下，以Ｎ元素计杉木和湿地松施肥量分别约为６．０ｇ和４．０ｇ，元素间的比例分别约为：１００Ｎ：４５Ｋ：１７ｐ：８．５Ｃａ：７．０Ｍｇ和１００Ｎ：５０Ｋ：１８Ｐ：６Ｃａ：６Ｍｇ。另外，还讨论了按营养原则改进施肥的必要性。

Application of Steady State Mineral Nutrition Principle to Fertilization of Potted Conifer seedlings

The fertilization experiment was conducted with one-vear-old Chinese fir(Cunnighamia lanceolata)and slash pine(Pinus elliottii Engelm)seedlings according to theprinciple of theory and technique of steady- state mineral nutrition,which was different fromconventional one. The nutrient solution was prepared by referring to the optimum nutrientweight proportion of pine species established by lngestad.The amount of fertilizer was 11.9,5, 95,2, 97gN per pot(seedling)for Chinese fir at high,middle and low level respectively,and 10,5,2.5gN for slash pine,which was added according to S- shape curve and only waterfor control.The height growth of current new shoot in high-N, middle-N, low-N treatmentwas increased by 156%,138%, 118%than that of control at the end of experiment for Chi-nese fir seedlings respectively,and 19.2%, 27.6%,3.9%for slash pine,Meanwhile,thebasal diameter for both species enhanced markedly.There was a significant difference in aver-age dry matter production of Chinese fir seedlings between high-N,middle-N,and control,which was close significant in slash pine.The nutrient characteristics of the two speciesseedlings were summarized by analysis of the nutrient contents in seedlings and changes insoil nutrient status of pots fertilization underlying a steady-state mineral nutrition were alsodiscussed in this paper.