不同施氮量对设施番茄生长与产量的影响及最佳用量

通过田间试验研究了二代日光节能温室不同施氮量对番茄生长、产量及其经济效益等的影响。结果表明,供试土壤全盐随施氮量的增加而增加,pH则随氮肥施用量的增加而显著降低;番茄株高、茎粗、叶绿素含量随施氮量增加而显著增加,施氮量超过600 kg.hm-2时,冠幅显著增加,造成枝叶徒长。番茄产量与施氮量呈典型的抛物线关系,即施氮量低于600 kg.hm-2时,随施氮量的增加,番茄产量增加;但进一步增加的施氮量导致产量下降,产投比也显著降低。施氮使番茄果实中可溶性糖含量的增加,总酸度下降,糖酸比的增大,Vc含量的增加,硝态氮的累积均达显著水平。设施番茄最高产量施氮量为646 kg.hm-2,最大经济效益施氮量为604 kg.hm-2。

Effect of N Fertilizer on Growth,Yield,Quality of Tomato and Optimum Application Rate of N in Greenhouse

A field experiment was conducted to study the effect of different N fertilizer application rate on tomato growth,yield and economic benefit in second generation greenhouse. The results showed that the total salts content was increased with the N application,yet pH was decreased at the same time. The height,stem diameter and chlorophyll of tomato were increased along with increment of N application. When more than 600 kg·hm~(-2) N was used in the field,the trunk breadth of tomato was significantly increased and led to overgrowth of leaves. The yield of tomato was increased along with enhanced N application rate,yet the yield of tomato was decreased if N applied more than 600 kg·hm~(-2). N application promotes the increase of soluble sugar,Vc,and NO_3~--N content,but reduce the total acidity. Changed ratio of sugar/acidity improves the quality of tomato. The reasonable application rate of N is 646 kg·hm~(-2). The optimum application rate of N is 604 kg·hm~(-2).