水氮联合调控对小油菜生长、产量及品质的影响

采用温室盆栽试验,研究了水氮联合调控对小油菜生长、产量及品质的影响。结果表明,灌水水平与施氮量对叶片数、叶面积、叶绿素与产量均有显著或极显著影响,这些指标均随灌水水平的提高而增加,随施氮量的增加呈抛物线趋势,在低氮(0.1 g·kg~(-1))与中氮处理(0.2 g·kg~(-1))达到最大,且差异不显著。中水高氮(田间持水量的75%,0.3 g·kg~(-1))耦合能显著提高小油菜Vc含量;灌水、施氮及其交互作用对可溶性糖与硝酸盐含量影响极显著;增加灌水能减轻高量氮肥对小油菜可溶性糖合成的抑制作用;不施氮处理硝酸盐含量均极显著低于施氮处理,高水低氮(田间持水量的90%,0.1 g·kg~(-1))与中水(田间持水量的75%)下的各个施氮处理硝酸盐含量较低。降低施氮量,适当增加灌水能增加Vc、可溶性糖含量,降低硝酸盐积累。综合考虑小油菜生长、产量及品质,中水低氮(田间持水量的75%,0.1 g·kg~(-1))为最佳水氮处理。

Regulation effects of different irrigation and nitrogen fertilization on growth,yield and quality of rape

The effects of irrigation levels and nitrogen rates on the growth parameters, yield and quality of rape were investiga-ted in a pot greenhouse experiment. The results indicated that effects of irrigation levels and nitrogen rates had significant or very significant impacts on the leaf number, leaf area, chlorophyll content and yield. All these indexes increased with the in-creasing irrigation level. And significant parabolic relationship was found between nitrogen rates and these indexes, which reached the maximum at nitrogen rate of 0. 1 g?kg-1 and 0. 2 g?kg-1 , and there was no significant difference between the two rates. The high nitrogen rate combined with medium irrigation improved Vitamin C content of rape. Water soluble sugar and nitrate concentration were affected by both irrigation level, nitrogen rate and their interaction effect significantly. Enhanced ir-rigation decreased the negative effect of high nitrogen rate on the synthesis of water soluble sugar. Compared with the nitrogen application treatment, no nitrogen treatment showed a lower nitrate concentration. In addition, high irrigation level combined with low nitrogen rate as well as the nitrogen treatments under moderate irrigation regimes showed relatively lower nitrate concen-tration. In summary, the quality of rape was improved by properly lowering the nitrogen rate and increasing irrigation amount. The combination of medium irrigation and low nitrogen amount (75%of field water capacity, 0. 1 g?kg-1 ) was recommended as the optimum pattern for a comprehensive performance of the growth, yield and quality of rape.