Ex-situ Spatial Distribution of Iron in Soil and its Effect on Uptake by Maize (Zea mays)

Abstract

This study investigated ex-situ spatial distribution of iron in soil and its effects on uptake of Fe by Zea mays. A greenhouse pot experiment which simulated three treatments control (0mg/kg Fe added, homogeneous (1000mg/kg Fe added) and heterogeneous (Simulated realistic heterogenity). Zea Mays was transplanted into the three treatments for six weeks after germination and initial establishment for four weeks. At harvest, root and shoot samples were collected and analyzed for Fe using the atomic absorption spectrometer (AAS) Thermos Fisher Scientific model ICE 3000 after acid digestion with nitric acid. The mean root Fe concentration in the control, homogeneous and heterogeneous treatments were 5965mg/kg, 7111mg/kg and 5389mg/kg respectively while the much shoot Fe concentration in the control, homogeneous and heterogeneous treatments were 1121mg/kg, 1405mg/kg and 831mg/kg respectively. There was no significant difference (p>0.05) in the shoot and root Fe concentration between treatments. This suggest that Zea Mays will acquire Fe from varying soil distribution effectively,  However the root and shoot Fe concentration was 0.5 two percent higher than the control and heterogeneous treatments indicating an exaggerated uptake of Fe on a homogeneous distributed soil medium which unrealistic in nature shoot Fe concentration were two times as low as the root Fe concentration which implies that Fe is accumulated to a greater degree on the root and translocation to the shoot is greatly impaired in this plant. However, the shoot Fe concentration showed significant amount of Fe that may be potentially fund on the edible fruit consumed by humans and animals. The concentration factor (CF) were 0.3656, 0.4394 and 0.3209 for the control, homogeneous and heterogeneous treatments respectively. This similar trend in concentration factor showed that this plant has same ability for uptake of Fe in varying nutrient patch. This study demonstrated that spatial distribution of Fe metals plays a significant role in their uptake by plants it also showed that the metal uptake is also affected by the nature of the sort and zea Mays may be a rich source of Fe if grown in Fe rich soil. The plant iron concentration exceeded the WHO limits on food which may power a health risk to consumers. This study has implications for improving the nutritional quality of maize especially in Fe deficient Soils.