叶面喷施铁和镁微肥对玉米幼苗碳代谢及生长的影响

为了探讨铁镁微肥对北方旱地玉米幼苗期碳代谢和生长的影响,对盆栽的玉米幼苗单独和混合喷施不同质量浓度的FeSO_4·7H_2O(250、500、750mg/L)和MgSO_4·7H_2O(0.5、1.0、1.5g/L)溶液,于2周后分析叶片中与碳代谢相关的生理生化指标以及生长指标的变化。结果表明,叶面喷施铁、镁微肥可以有效提高叶片的叶绿素质量分数、光合能力以及可溶性糖和淀粉的质量分数,增强玉米的碳代谢能力;同时,可以显著促进根系的生长,提高根冠比。其中,适合玉米幼苗生长的最佳喷施质量浓度分别是500 mg/L的FeSO_4·7H_2O、1g/L的MgSO_4·7H_2O和250mg/L的FeSO_4·7H_2O与0.5g/L的MgSO_4·7H_2O混合溶液。因此,叶面喷施适当质量浓度的铁或镁微肥可以有效提高玉米幼苗的碳代谢能力,促进植株、特别是根系的生长,这对于玉米后期的生长发育也具有积极的意义。

Effects of Spraying Fe and Mg Liquid Fertilizer on Carbon Metabolism and Growth of Maize Seedlings

To explore effects of Fe and Mg fertilizer on carbon metabolism and growth of maize seedlings grown in North China, different concentrations of single and combined FeSO₄·7H₂O (250 mg/L,500 mg/L,750 mg/L) and MgSO₄·7H₂O (0.5 g/L,1 g/L,1.5 g/L) solutions were sprayed on the leaf surface of potted maize seedlings. Two weeks later, the indicators related to leaf carbon metabolism and growth were investigated. Results showed that spraying the Fe and Mg liquid fertilizers effectively increased the contents of chlorophylls, the ability of photosynthesis, and the mass fraction of soluble sugar and starch in leaves of maize, hence, enhancing leaf carbon metabolism ability of the plants. Meanwhile, root growth of plants was significantly promoted, leading to an increase in the root/shoot ratio. The most suitable mass concentrations applied in this pot experiments were 500 mg/L FeSO₄·7H₂O, 1 g/L MgSO₄·7H₂O, or the mixture of 250 mg/L FeSO₄·7H₂O + 0.5 g/L MgSO₄·7H₂O. In conclusion, spraying suitable mass concentrations of Fe and Mg liquid fertilizers on leaves of maize seedlings could effectively enhance leaf carbon metabolism ability and facilitate root growth of maize.