PBL Netherlands Environmental Assessment Agency, The Hague, The Netherlands.
International Institute of Tropical Agriculture (IITA), Kampala, Uganda.
PLoS One. 2019 Jan 17;14(1):e0210642. doi: 10.1371/journal.pone.0210642. eCollection 2019.
Malnutrition, the suboptimal consumption of essential nutrients like zinc, severely affects human health. This burden of malnutrition falls disproportionally heavy on developing countries, directly increasing child mortality and childhood stunting, or reducing people's ability mending diseases. One option to combat malnutrition is to blend missing nutrients in crop fertilizers, thereby increasing crop yields and possibly the nutrient density in harvested crop products, thus enriching crop products destined for human consumption. But, the effectiveness of so-called agronomic fortification remains ill-understood, primarily due to a paucity of field trials. We hypothesize that, if at all this is an effective strategy, there should exist a causal link between malnutrition and natural variation in the quality of soils to begin with. Until now, data limitations prevented the establishment of such a link, but new soil micronutrient maps for Sub-Saharan Africa allow for a detailed assessment. In doing so, we find statistically significant relations between soil nutrients and child mortality, stunting, wasting and underweight. For instance, a simultaneous increase in soil densities of copper, manganese and zinc by one standard deviation reduces child mortality by 4-6 per mille points, but only when malaria pressure is modest. The effects of soil nutrients on health dissipate when malaria pressure increases. Yet, the effects are fairly small in magnitude suggesting that except for a few regions, agronomic fortification is a relatively cost ineffective means to combat malnutrition.
营养不良，即锌等重要营养物质摄入不足，严重影响人类健康。发展中国家受营养不良的影响尤其严重，直接导致儿童死亡率和儿童发育迟缓率上升，或降低人们抵抗疾病的能力。应对营养不良的一种方法是在作物肥料中混合缺失的营养物质，从而提高作物产量，并可能提高收获作物产品的营养密度，从而丰富人类食用的作物产品。但是，所谓的农业强化的有效性仍然知之甚少，主要是因为田间试验的缺乏。我们假设，如果这确实是一种有效的策略，那么从一开始，营养不良和土壤质量的自然变化之间就应该存在因果关系。到目前为止，数据限制阻止了这种联系的确立，但撒哈拉以南非洲地区新的土壤微量营养素图允许进行详细评估。在这样做的过程中，我们发现土壤养分与儿童死亡率、发育迟缓、消瘦和体重不足之间存在统计学上的显著关系。例如，土壤中铜、锰和锌的密度同时增加一个标准差，可使儿童死亡率降低 4-6 个千分点，但前提是疟疾压力适中。当疟疾压力增加时，土壤养分对健康的影响就会消失。然而，其影响的幅度相当小，这表明除了少数地区外，农业强化是一种相对成本效益不高的应对营养不良的方法。
