湿地松容器苗稳态营养与土壤矿化作用的研究

STUDIES ON STEADY STATE MINERAL NUTRITION AND MINERALIZATION FOR CONTAINER-GROWN SEEDLINGS OF SLASH PINE

采用稳态营养理论与技术对塑料薄膜袋湿地松芽苗进行营养物相对添加速率０、５３％、６４％、７５％４种施肥处理（简称０、５３、６４、７５处理）。测量苗木地径、株高（茎干长度）、株干重，得到６４处理比０处理分别提高１４９％、２４５％、３９６％，统计学上差异显著或极显著。表明６４处理苗木生长最佳。定量分析试验前、后根介质有效养分含量、苗体营养元素累积等，得到６４最优处理的效果集中体现在苗体Ｎ、Ｐ、Ｋ元素累积量比０处理分别提高７９４％、５８５％、４１９％；系统Ｎ、Ｐ、Ｋ、Ｃａ、Ｍｇ元素增加量比０处理分别提高３２３％、５６９％、３６１％、９２２％、２５３％，土壤Ｎ、Ｐ、Ｋ营养物通量密度分别提高２３７％、３６３％、３０７％；土壤脲酶、蛋白酶、过氧化氢酶、中性磷酸酶活性分别比试验初提高４０３％、４５５％、４０％、１４４５％。表明较适宜的营养物相对添加速率不仅促进苗木最佳生长，而且对提高土壤酶活性和土壤营养物通量密度，以及提高营养物利用率也是适宜的。对稳态矿质营养促进土壤矿化作用机理及其先进性进行了讨论。

お? Seedlings of slash pine (Pinus elliottii Engelm.) grown in plastic film bags(15cm×23cm) were treated with liquid fertilizer at 4 relatively different addition rates, i.e.0,53%,64%, and 75%,following the theory and technique of steady state mineral nutrition. The results indicated that the basal diameter, stem length (seedling height), and dry matter production of the seedlings under the 64% treatment increased by 149%,245%, and 396% in comparison with the seedlings under the 0 treatment, which were significantly different at 005 or 001 level. Through quantitative analyses of the available nutrient contents in the root media and the amounts of nutrient element accumulated in the seedlings of various treatments in the beginning and at the end of the experiment, it was shown that 64% treatment was of the best effects with nutrient accumulations of N,P,K elements in seedlings increased by 794%,585% and 419% over the 0 treatment, and the increments of N,P,K,Ca,Mg nutrient element contained in this treatment system by 323%,569%,361%,922% and 253%, respectively in comparison with 0 treatment. At the same time, the soil nutrient flux density of N,P,K increased by 237%,363%,307% in comparison with 0 treatment,respectively, and the enzyme activities of urease,proteinase,hydrogen peroxidase,neutral phosphatase were 403%,455%,40%,1445% higher than those at the beginning of the experiment. It is concluded that the comparatively suitable nutrient relative addition rate not only promotes seedling growth, but also induces soil enzyme activity and soil nutrient flux density, as well as nutrient use efficiency.The mechanism of steady state mineral nutrition to promote soil mineralization, and its advantage were discussed in this paper.