不同肥料施用对大蒜生长、品质和氮代谢的影响

Effects of Different Fertilization on the Growth,Quality and Nitrogen Metabolism of the Garlic Seedling

土壤培养条件下,研究过量施用氮肥以及氮肥与菜籽饼肥配合施用对大蒜苗期生长发育、产量、品质和氮代谢的影响,结果表明:随着化学氮肥过量施用,大蒜苗期生长发育受到抑制,株高、叶长、叶宽和产量均显著降低,叶片中维生素C含量显著降低,叶绿素、可溶性糖、可溶性蛋白质和游离氨基酸含量先升高,后又降低,硝酸盐含量和硝酸还原酶活性增加。在较高施氮水平下,施用菜籽饼肥或饼肥与化肥配施可避免单一施用化肥对大蒜生长发育的抑制作用,株高、叶长、叶宽和产量均明显增加,叶片叶绿素、游离氨基酸和硝酸盐含量显著降低,可溶性糖含量也有降低趋势,可溶性蛋白质含量增加,施用饼肥的大蒜叶片维生素C含量显著增加,硝酸还原酶活性仍较高,保证了大蒜的食用品质。

The effects of excessive application of nitrogen fertilizer combining with the application of rapeseed cake and nitrogen fertilizer on the growth, quality and nitrogen metabolism of the garlic seedling were studied under soil culture condition. Excessive application of nitrogen fertilizer significantly de- creased the plant height, leaf length, leaf width, yield and the content of vitamin C and markedly increased the content of nitrate and the activity of nitrate reductase in leaves of the garlic seedling. The contents of chlorophyll, soluble sugar, soluble protein and free amino acid in the leaves of the garlic seed- ling was enhanced at high nitrogen level of 0. 4 g/kg, then reduced at excessive nitrogen level of 0. 6 g/kg. Compared with chemical nitrogen fertilizer, the application of rape seed cake or combining it with nitrogen fertilizer obviously enhanced the plant height, leaf length, leaf width, yield and the content of vitamin C in leaves of the garlic seedling and improved the content of soluble protein and the activity of nitrate reductase, notablely depressed the content of chlorophyll, free amino acid and nitrate, also decreased the content of soluble sugar. It indicated that the application of rapeseed cake or combining it with chemical fertilizer might escape the toxicity due to excessive application of inorganic fertilizer and improve the quality and yield of the garlic seedling.