Blood powder, a source of iron for plants

Abstract

Natural materials that possess chelating ability for iron (Fe) such as plant and animal residues have been used as Fe sources for plants. A solution culture study and a soil incubation study were conducted to investigate use of poultry blood powder as an Fe source for plants. Iron in blood is chelated by the heme group present in hemoglobin molecule. Stability of Fe in this chelate was found to be high in neutral and acidic solutions. Only a very small fraction (0.1 to 0.2%) of total Fe could be extracted from blood powder by a 0.1M calcium chloride (CaCl₂) solution. In the culture solution study, Fe from blood powder was as effective as Fe from FeEDDHA in preventing Fe chlorosis of soybeans. Yield and Fe content of plants receiving blood powder were higher than the control and were not different from the plants receiving FeEDDHA. The incubation study using two soils, two Fe sources and three Fe rates indicated that DTPA‐Fe increased from application of 5, 10 or 15 mg of Fe as blood powder/kg in one soil (Sudan) and from application of 10 or 15 mg of Fe as blood powder/kg in the other soil (Vernamkhast). Blood powder is a suitable Fe source for hydroponically grown plants and increases Fe availability when applied to soil.