Mutambu Dominic, Kihara Job, Mucheru-Muna Monicah, Bolo Peter, Kinyua Michael
Department of Environmental Sciences and Education, Kenyatta University, P.O Box 43844-00100, Nairobi, Kenya.
Alliance of Bioversity International and the International Center for Tropical Agriculture (CIAT) c/o International Centre of Insect Physiology and Ecology (ICIPE), Duduville Campus Off Kasarani Road, P.O Box 823 - 00621, Nairobi, Kenya.
Heliyon. 2023 May 5;9(5):e16040. doi: 10.1016/j.heliyon.2023.e16040. eCollection 2023 May.
Zinc deficiency in agricultural soils is a current global agroecosystems challenge. Maize exhibits elevated susceptibility to Zn deficiency and low response to zinc fertilization. As a result, there are contradicting literature reports on the crop response to zinc fertilization. This meta-analysis synthesized the current evidence on maize response to zinc fertilization from different studies and highlighted the potential innovations to improve the crop response to zinc application. Systematic literature searches were conducted on the Web of Science and Google Scholar for peer-reviewed publications. From the selected publications, data extracted were maize grain yield and maize grain zinc concentration. The meta-analysis was conducted in R statistical environment using the package. The ratio of means was the chosen effect size measure used. The assessment of effect size heterogeneity showed that the study effect sizes were significantly heterogeneous and also publication bias was evident. The analysis showed 17% and 25% maize grain yield and grain zinc concentration response to zinc fertilization. As a result, zinc fertilization was associated with yield increments of up to 1 t ha and 7.19 mg kg grain zinc concentration over the control (no zinc application). Despite the observed maize grain response to zinc application, the median concentration of grain Zn was below the 38 mg kg recommended maize grain zinc concentration to combat human zinc deficiency (). As a result, potential innovations likely to achieve sufficient maize grain zinc content were highlighted including the use of nano-particulate zinc oxide, foliar zinc application, timing of zinc application, precision fertilization and zinc micro-dosing. Due to scanty literature on the progress of these innovations in maize, follow-up studies are recommended to evaluate their potential success in the agronomic bio-fortification of maize with zinc.
农业土壤中的锌缺乏是当前全球农业生态系统面临的一项挑战。玉米对锌缺乏表现出较高的敏感性，对锌肥的反应较低。因此，关于作物对锌肥反应的文献报道存在矛盾。这项荟萃分析综合了不同研究中关于玉米对锌肥反应的现有证据，并强调了提高作物对锌施用反应的潜在创新方法。我们在科学网和谷歌学术上进行了系统的文献检索，以查找同行评审的出版物。从选定的出版物中，提取的数据包括玉米籽粒产量和玉米籽粒锌浓度。荟萃分析是在R统计环境中使用相关软件包进行的。均值比是所选用的效应量度量。效应量异质性评估表明，研究效应量存在显著异质性，且发表偏倚明显。分析表明，玉米籽粒产量和籽粒锌浓度对锌肥的反应分别为17%和25%。因此，与对照（不施锌）相比，锌肥施用使产量增加了1吨/公顷，籽粒锌浓度增加了7.19毫克/千克。尽管观察到玉米籽粒对锌施用有反应，但籽粒锌的中位浓度低于为防治人体锌缺乏而推荐的38毫克/千克玉米籽粒锌浓度。因此，突出了可能实现足够玉米籽粒锌含量的潜在创新方法，包括使用纳米颗粒氧化锌、叶面施锌、锌施用时间、精准施肥和微量施锌。由于关于这些创新方法在玉米上进展的文献较少，建议开展后续研究，以评估它们在玉米锌农艺生物强化方面取得成功的潜力。
