Iron Enriched Green Manure Can Increase Wheat Fe Concentration in Pb-polluted Soil in the Presence of <i>Piriformospora Indica (P.indica)</i>

Soil pollution with heavy metals and iron (Fe) malnutrition is big concern of industrial areas in arid and semi-arid regions. We studied the potential of Fe-enriched green manures application and Piriformospora indica (P.indica) to increase grain Fe concentration of two bread wheat genotypes differing in Fe efficiency (Triticum aestivum L. cvs. Falat, and Durum) in a Pb-polluted soil. To prepare Fe-enriched green manures sunflower, corn, and canola were cultivated in the soils treated with 0%, 0.5%, 1% and 1.5% (W/W) of iron slag, converter slag, and elemental sulfur. After 70 days, the plants were harvested and the Fe concentration in their biomass was measured. The plants grown in 1.5% elemental sulfur were selected as green manures due to their higher Fe concentration than those grown in soils treated with other industrial byproducts studied. Application of sunflower residues and presence of P. indica in Pb-polluted soil increased the grain Fe concentration of Falat and Durum wheat genotypes from 48.8 to 132.7 and 40.2 to 118.8 mg kg−1, respectively. The response of wheat plants to the presence of P. indica and green manure application was significantly affected by the wheat genotype. Application of sunflower residues increased soil microbial respiration and dissolved organic carbon which was consistently magnified by the presence of P. indica. This study showed that agricultural management, including the use of Fe-enriched green manure, could be asuitable method to increase Fe concentration and reduce Pb concentration in wheat grains grown in Pb-polluted soils of arid and semi-arid regions.