Botoman Lester, Chimungu Joseph G, Bailey Elizabeth H, Munthali Moses W, Ander E Louise, Mossa Abdul-Wahab, Young Scott D, Broadley Martin R, Lark R Murray, Nalivata Patson C
Department of Crop and Soil Sciences Lilongwe University of Agriculture and Natural Resources Lilongwe Malawi.
Department of Agricultural Research Services Chitedze Agricultural Research Station Lilongwe Malawi.
Plant Direct. 2022 Nov 3;6(11):e458. doi: 10.1002/pld3.458. eCollection 2022 Nov.
Zinc (Zn) deficiency remains a public health problem in Malawi, especially among poor and marginalized rural populations, linked with low dietary intake of Zn due to consumption of staple foods that are low in Zn content. The concentration of Zn in staple cereal grain can be increased through application of Zn-enriched fertilizers, a process called agronomic biofortification or agro-fortification. Field experiments were conducted at three Agricultural Research Station sites to assess the potential of agronomic biofortification to improve Zn concentration in maize grain in Malawi as described in registered report published previously. The hypotheses of the study were (i) that application of Zn-enriched fertilizers would increase in the concentration of Zn in maize grain to benefit dietary requirements of Zn and (ii) that Zn concentration in maize grain and the effectiveness of agronomic biofortification would be different between soil types. At each site two different subsites were used, each corresponding to one of two agriculturally important soil types of Malawi, Lixisols and Vertisols. Within each subsite, three Zn fertilizer rates (1, 30, and 90 kg ha) were applied to experimental plots, using standard soil application methods, in a randomized complete block design. The experiment had 10 replicates at each of the three sites as informed by a power analysis from a pilot study, published in the registered report for this experiment, designed to detect a 10% increase in grain Zn concentration at 90 kg ha, relative to the concentration at 1 kg ha. At harvest, maize grain yield and Zn concentration in grain were measured, and Zn uptake by maize grain and Zn harvest index were calculated. At 30 kg ha, Zn fertilizer increased maize grain yields by 11% compared with nationally recommended application rate of 1 kg ha. Grain Zn concentration increased by 15% and uptake by 23% at the application rate of 30 kg ha relative to the national recommendation rate. The effects of Zn fertilizer application rate on the response variables were not dependent on soil type. The current study demonstrates the importance of increasing the national recommendation rate of Zn fertilizer to improve maize yield and increase the Zn nutritional value of the staple crop.
锌（Zn）缺乏仍是马拉维的一个公共卫生问题，尤其是在贫困和边缘化的农村人口中，这与食用锌含量低的主食导致锌的膳食摄入量低有关。通过施用富含锌的肥料可以提高主要谷物中锌的含量，这一过程称为农艺生物强化或农业强化。如先前发表的注册报告所述，在三个农业研究站进行了田间试验，以评估农艺生物强化提高马拉维玉米籽粒锌含量的潜力。该研究的假设是：（i）施用富含锌的肥料会增加玉米籽粒中锌的含量，以满足锌的膳食需求；（ii）玉米籽粒中的锌含量和农艺生物强化的效果在不同土壤类型之间会有所不同。在每个站点使用了两个不同的子站点，每个子站点对应马拉维两种重要农业土壤类型之一，即淋溶土和变性土。在每个子站点内，采用标准土壤施用方法，以随机完全区组设计，对试验小区施用三种锌肥施用量（1、30和90千克/公顷）。根据一项初步研究的功效分析，本试验在三个站点中的每个站点都有10次重复，该初步研究发表在本试验的注册报告中，旨在检测相对于1千克/公顷的浓度，90千克/公顷时籽粒锌浓度增加10%。收获时，测量了玉米籽粒产量和籽粒中的锌浓度，并计算了玉米籽粒对锌的吸收量和锌收获指数。与国家推荐的1千克/公顷施用量相比，30千克/公顷的锌肥使玉米籽粒产量提高了11%。相对于国家推荐施用量，30千克/公顷施用量下的籽粒锌浓度增加了15%，吸收量增加了23%。锌肥施用量对响应变量的影响不依赖于土壤类型。当前研究表明提高锌肥国家推荐施用量对于提高玉米产量和增加主粮作物锌营养价值的重要性。
