土壤盐分对油菜氮素积累、运转及利用效率的影响

Effects of soil salt content on accumulation, translocation and utilization efficiency of nitrogen in rapeseed

【目的】比较不同盐分含量条件下油菜产量、品质等性状差异,初步探讨盐分含量对油菜氮素积累、运转及利用效率的影响机制。【方法】以杂交油菜宁杂1818和盐油杂3号为材料,在盐分含量为2.7 g/kg(低盐)和4.4 g/kg(高盐)的土壤上连续两年进行了田间试验。在初花期和成熟期取样,定期收集田间落叶,测定植株干物质积累量、氮素含量及籽粒品质,计算了不同盐分含量土壤条件下油菜氮素积累、运转及氮素籽粒生产效率。【结果】高盐土壤上油菜的初花期和成熟期时间较低盐土壤的推迟3~4天,产量、总生物量和氮素积累总量显著降低,宁杂1818和盐油杂3号两年产量平均下降幅度分别为23.6%和26.1%。与低盐土壤相比,高盐土壤上油菜籽粒含油量显著降低,蛋白质含量显著增加,宁杂1818和盐油杂3号两年油分含量平均下降幅度均为4.6%,蛋白质含量平均增加幅度分别为6.4%和9.4%。盐分含量对根系和叶片的氮素运转率影响较小。高盐土壤上油菜茎枝中的氮素运转率和氮素籽粒生产效率较低盐土壤的低,宁杂1818和盐油杂3号茎枝氮素运转率两年平均下降幅度均约为14.2%,氮素籽粒生产效率平均下降幅度分别为6.8%和9.3%。【结论】高盐土壤上油菜的产量、总生物量、氮素积累总量以及籽粒含油量较低盐土壤显著降低,籽粒蛋白质含量显著增加。高盐土壤上油菜茎枝中氮素运转率的显著降低是导致油菜氮素籽粒生产效率降低的重要因素之一。

[ Objectives ] The objective of this study was to research the influence of soil salt-ion content on accumulation, translocation and utilization efficiency of nitrogen in rapeseed. [ Methods ] Rapeseed cultivars of Ningza 1818 and Yanyouza 3 were planted in soils with salt contents of 2.7 g/kg （low salt） and 4.4 g/kg （high salt） in 2014-2015 and 2015-2016. Samples of the deciduous leaves were collected regularly. The dry matter weight, N content were measured, and the seed qualities were determined. The characteristics of nitrogen accumulation, translocation rate and use efficiency for grain production （NUEg） were calculated. [ Results ] The early flowering stage and ripening stage of rapeseed in high salt soil started 3 to 4 days later compared with those in low salt soil, the yields, biomass and N accumulation amounts were decreased. The average yield decline ranges of Ningza 1818 and Yanyouza 3 were 23.6% and 26.1%, the average oil content decline ranges were all 4.6%, and the average protein content increase ranges were 6.4% and 9.4%, respectively. The N translocation rates in roots and leaves in both soils were similar, but those in stems were decreased with the average decline range of 14.2% in both cultivars, and the NUEg were decreased in the average range of 6.8% in Ningza 1818 and 9.3% in Yanyouza 3, respectively. [ Conclusions ] In high salt content soil, the yield, biomass, N accumulation amount and oil content of rapeseed are decreased, and the protein content is increased. The significant decrease in nitrogen translocation rate of stem might be one of the mechanisms for the reduced NUEg.