不同氮肥水平对甜瓜“南海蜜”生长.品质及产量的影响

目的]研究不同氮肥浓度对甜瓜“南海蜜”生长、品质及产量的影响。方法]在无土栽培模式下，设计4个氮肥浓度处理（7、10、13、16mmol／L）。结果]在幼苗期，氮肥水平低的甜瓜较氮肥水平高的的叶面积大；在伸蔓期，中等氮肥水平的甜瓜叶面积最大；在授粉期后，氮肥水平高的甜瓜叶面积最大。随着氮肥的增加，甜瓜结果中期果实可溶性固形物和可溶性糖含量显著增加，而过多的氮肥对结果后期和收获期时甜瓜的可溶性固形物和可溶性糖含量没有影响。低氮肥水平的甜瓜Vc含量显著高于高氮肥水平。高氮肥水平对甜瓜产量有抑制作用。结论]N10处理经济效应最高，其氮肥用量为125．10kg／hm^2，产量为72730kg／hm^2，除氮肥成本后产值为264710元／hm^2。

Effects of Different Ratios of Nitrogen Nutrient on Growth,Quality and Yield of Soilless Cultivated Melon ＂Nan Hai Mi＂

Objective ] The effects of nitrogen nutrient levels on vegetative growth, quality and yield of melon ＂ Nan Hai Mi＂ were studied. Method] Under the condition of soil]ess cultivation, four kinds of different nitrogen concentration in nutrient solution which include N7 （7 mmoL/L）, N10 （10 mmol/L）, N13 （13 mmol/L）and N16（ 16 mmoL/L） were designed. Result] Nitrogen nutrient level treatment showed significant effects on leaf area increased, melon had larger leaf area under lower nitrogen nutrient level treatment condition than higher nitrogen nutrient level in seedling stage, melon had larger leaf area under medium nitrogen nutrient level treatment condition than other nitrogen nutrient level in stem growth period, melon had larger leaf area under higher nitrogen nutrient level treatment condition than lower nitrogen nutrient in pollination period. Soluble solids and soluble sugar contents of fruit were increased significantly by applying nitrogen nutrient in middle period of fruit. Soluble solids and soluble sugar contents of fruit were increased no significantly by applying nitrogen nutrient in harvest period, even maybe growth was inhibited. Vc contents of fruit of low nitrogen level was higher significantly than that of high nitrogen level, yield was inhibited by high nitrogen level. Conclusion] The economic effect reached the highest point in treatment which nitrogen nutrient levels was 10 mmol/L, yield reached 72 730 kg/hm^2 , nitrogen fertilizer was 125.10 kg/hm^2 , in addition to the cost of nitrogen fertilizer after the output value was 264 710 CNY/hm^2.