Fertilizer management and soil type influence grain zinc and iron concentration under contrasting smallholder cropping systems in Zimbabwe
Fertilizer management and soil type influence grain zinc and iron concentration under contrasting smallholder cropping systems in Zimbabwe
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DOI：
10.1038/s41598-019-42828-0
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发表时间：
2019-04-23
影响因子：
4.6
通讯作者：
Mapfumo, Paul
中科院分区：
文献类型：
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作者：
Manzeke, Muneta G.;Mtambanengwe, Florence;Mapfumo, Paul
微量营养素缺乏在南部非洲的粮食系统中仍然普遍存在，尽管通过作物育种和农学在生物强化方面取得的进展为解决这些问题提供了机会。在津巴布韦两种不同的农业生态环境下，我们确定了锌和铁的基线土壤有效性，以及土壤类型和农民管理对谷物和豆科谷物中可提取土壤锌和铁及其随后浓度的影响。2015- 2016年，在津巴布韦的Hwedza和Mutasa地区对350个不同土壤类型的地点进行了土壤和作物调查。采用继承分层随机抽样设计，对不同生产力水平的田地（指定为“最高”和“最低”生产力田地）进行抽样。玉米（Zea mays）、高粱（sorghum bicolor）、谷子（Eleusine coracana）和豇豆（Vigna unguiculata）籽粒锌和铁含量普遍不足。线性混合效应（LME）模型表明，二乙烯三胺五乙酸（DTPA）可提取土壤锌浓度和粮食锌浓度主要受田间生产力水平的影响。高产田的土壤锌含量（平均0.8 mg kg(-1)）是低产田的2倍以上，籽粒锌含量平均为25.2 mg kg(-1)，比低产田高13%。田间生产力水平和土壤总锌浓度对dtpa可提取土壤锌浓度的交互作用表明，有机质管理对释放土壤锌的不可用形式有潜在贡献。土壤可提取铁和籽粒铁浓度主要受土壤类型和作物类型的影响。LME模型方法揭示了额外的土壤地球化学协变量影响dtpa可提取土壤Zn和Fe浓度以及区域内谷物Zn和Fe浓度。因此，未来的研究可以在更广泛的空间尺度上发现它们在作物锌和铁营养可持续管理中的作用。
Micronutrient deficiencies remain prevalent in food systems of southern Africa, although advances in biofortification through crop breeding and agronomy provide opportunities to address these. We determined baseline soil availability of zinc (Zn) and iron (Fe) and the effects of soil type and farmer management on extractable soil Zn and Fe and subsequent concentration in cereal and legume grains under two contrasting agro-ecologies in Zimbabwe. Soil and crop surveys were conducted in Hwedza and Mutasa Districts of Zimbabwe in 2015-16 on 350 locations over different soil types. Fields with different levels of productivity (designated as "most" and "least" productive fields) were sampled using an inherited hierarchical randomized sampling design. Grain Zn and Fe concentration in maize (Zea mays), sorghum (Sorghum bicolor), finger millet (Eleusine coracana) and cowpea (Vigna unguiculata) were generally insufficient for adequate human nutrition. A Linear Mixed Effects (LME) model revealed that diethylene triamine penta-acetic acid- (DTPA) extractable soil Zn concentration and grain Zn concentration were affected primarily by field productivity level. DTPA-extractable soil Zn concentration was more than two-fold greater on the most productive fields (mean 0.8 mg kg(-1)) than on the least productive fields, with mean grain Zn concentration of 25.2 mg grain Zn kg(-1) which was 13% greater than seen on the least productive fields. An interaction effect of field productivity level and total soil Zn concentration on DTPA-extractable soil Zn concentration suggests potential contribution of organic matter management to unlocking unavailable forms of soil Zn. DTPA-extractable soil Fe and grain Fe concentration were primarily affected by soil type and crop type, respectively. The LME modelling approach revealed additional soil geochemical covariates affected DTPA-extractable soil Zn and Fe concentration and grain Zn and Fe concentration within Districts. Future studies can therefore be powered to detect their roles at wider spatial scales for sustainable management of crop Zn and Fe nutrition.