Summary
This geospatial survey of 1,600 locations across Malawi characterised the spatial variation in maize grain zinc concentration and identified key soil and environmental factors explaining this variation. Soil pH, labile zinc fractions (isotopically exchangeable and DTPA-extractable), and downscaled mean annual temperature were significant predictors of grain zinc concentration in a linear mixed model framework. The findings suggest that spatially targeted interventions to increase dietary zinc intake, such as biofortification, could be informed by mapping these soil and landscape factors.
UK applicability
The findings are of limited direct applicability to UK farming systems, where dietary zinc deficiency is uncommon and maize is not a staple crop. However, the methodological approach of linking soil properties to crop micronutrient composition may be relevant to UK research on nutrient density in arable crops and soil quality assessment.
Key measures
Maize grain zinc concentration (mg kg⁻¹); soil pH (water); isotopically exchangeable zinc (Zn_E); DTPA-extractable zinc (Zn_DTPA); downscaled mean annual temperature; spatial variation at distances up to ~100 km
Outcomes reported
The study identified soil properties (pH, isotopically exchangeable zinc, DTPA-extractable zinc) and mean annual temperature as predictors of spatial variation in maize grain zinc concentration across Malawi. Mean grain zinc concentration was 21.8 mg kg⁻¹ (range 10.0–48.1) across 1,600 locations, with robust evidence for spatially dependent variation up to approximately 100 km. Spatial predictions from the linear mixed model provide a basis for targeting biofortification and dietary zinc intervention strategies.
Topic tags
Dig deeper with Pulse AI.
Pulse AI has read the whole catalogue. Ask about this record, its theme, or how the findings apply to UK farming and policy — every answer cites the underlying studies.