磁化处理促进施氮条件下葡萄氮素的代谢和分布

以‘夏黑’葡萄扦插苗为试验材料,采用盆栽试验方法,分析了磁化水灌溉后葡萄叶片、茎和根系中不同形态氮素含量、氮素代谢关键酶活性以及不同氮源的贡献率,探讨磁化作用对‘夏黑’葡萄扦插苗生长以及氮素吸收、分配和利用的影响。以~(15)N为外源氮肥,分3次施入土壤中。试验设置4个处理,包括:磁化水灌溉处理、非磁化水灌溉处理、磁化水灌溉+施氮处理、非磁化水灌溉+施氮处理。磁化处理组中利用磁化装置处理灌溉水。结果表明:1)施氮条件下,与非磁化处理相比,磁化处理后葡萄叶片、根系和全株的全氮量提高,但是肥料中~(15)N对不同器官中氮素的贡献率无显著差异;叶片和根系的氮素利用率显著提高;全氮在叶片中分配率显著提高,在茎中的分配率则显著降低。2)与非磁化处理相比,磁化处理后葡萄叶片中谷氨酰胺合成酶和谷氨酸合酶活性显著提高,根系中显著降低。3)与单独施氮相比,磁化水灌溉+施氮提高了土壤氮含量;氮肥中~(15)N利用率提高,损失率降低。由以上研究结果可以看出,磁化水灌溉不仅可提高氮素代谢关键酶活性,而且可提高不同器官中氮素营养的吸收和利用,从而改变了氮素在不同器官中的分布。

Effect of applying nitrogen fertilizer on nitrogen metabolism and distribution in grapevine under magnetic treatment of water

The aim of this study was to investigate nitrogen (N) absorption and distribution, as well as nitrogen-use efficiency, of grape seedlings grown in magnetic and non-magnetic water treatments. One-year-old grape (Vitis vinifera×V. labrusca L. hybrid) seedlings were planted in pots and fertilized with exogenous ¹⁵N, and then grown under different magnetic water treatments or a control (untreated irrigated water). The proportional content of different forms of N, the activities of key enzymes relative to N metabolism, and the fate of N in leaves, stems, and roots of treated grape seedlings were analyzed. Under N application, we found that compared with the non-magnetic treatment (NMT), the magnetic treatment of water (MTW) appeared to promote N uptake and N-use efficiency in treated grape seedlings, while also optimizing the N allocation pattern and improving N assimilation ability of N fertilizer. We also identified that the total content of N in the leaves and roots (and in the plant generally) of treated seedlings were significantly increased when grown in the MTW. Conversely, the degree of contribution by N fertilizer (Ndff) to total N was not significantly different. Notably, the N utilization efficiencies of leaves and roots was significantly increased under MTW compared to that of the NMT treatment. The N allocation rate in leaves showed a marked increase under MTW, while that in stems showed a significant decrease. Additionally, it was found that the activities of glutamine syntheses and glutamic synthase increased significantly in the leaves, but decreased in the roots of treated seedlings. Finally, we identified that MTW increased the N-use efficiency and fixing capacity of plants and, additionally, alleviated the loss of N fertilizer in grape seedlings. Compared with treatments applying N fertilizer, the content of inorganic N and total N were promoted by 3.03%-3.45% in soil when exposed to MTW with N application. The utilization rate, residual rate, and recovery rate of seedlings increased by 36.39%-76.50% under MTW after the addition of ¹⁵N, and the loss rate of ¹⁵N decreased significantly (35.33% reduction). Based on our findings, it appears that the magnetic treatment of water can be effective in promoting N absorption and allocation in grape seedlings while also improving the plant fertilizer use efficiency from soil.