Correcting Iron Deficiency in Corn with Seed Row–Applied Iron Sulfate

Abstract

Fe deficiency is foliar application of Fe solutions. This method of correction usually alleviates chlorosis; how-Corn (Zea mays L.) grown on calcareous, high-pH soils is susceptiever, the results from a foliar application may be only ble to Fe deficiency, which can reduce grain yield by as much as 20%.temporary and actually depress the plant's Fe stress mech-The objective of this study was to evaluate several treatments of FeSO 4 anisms by preventing the increase in Fe-reducing capacthat could be used with precision-farming technologies to alleviate Fe deficiency in irrigated corn. Three sites in 1999 and four in 2000 were ity of the roots that would normally occur during Fe selected (based on a history of Fe deficiency) for small-plot (3 by deficiency (Rö mheld and Marschner, 1986b). Other in-12.2 m) studies in western Kansas. In 1999, five treatments, including tensively researched Fe sources include organic comfour rates of FeSO 4 ·H 2 O (0-81 kg ha Ϫ1 product) applied in the seed pounds, acidifying amendments, industrial by-products, row and one foliar treatment (chelated Fe), were evaluated. In 2000,and animal wastes (Olson, 1950;Wallace et al., 1976; two additional treatments, CaSO 4 ·2H 2 O (85 kg ha Ϫ1 product) and Thomas and Mathers, 1979). liquid FeSO 4 ·7H 2 O (91 kg ha Ϫ1 product) applied in the seed row, Researchers are faced with many challenges when were included. Grain yield increased linearly with increasing rates of working with Fe fertilizer. Cihacek (1984) observed that FeSO 4 ·H 2 O at four of seven site-years, increasing 0.02 Mg ha Ϫ1 for researchers find mixed results because treatments often each kilogram per hectare of FeSO 4 ·H 2 O applied. Based on yield show little or no visual effect on Fe chlorosis, grain responses observed in this study, 81 kg ha Ϫ1 FeSO 4 ·H 2 O was the most consistent treatment for correcting Fe deficiency in corn. If the average yields vary from year to year, or effective treatments are yield response obtained in this study can be achieved on 15% of an not economically feasible for the producer. Numerous individual cornfield, the expected return would be $3.00 ha Ϫ1 for the factors contribute to the inconsistent results, but perentire field. Current precision-farming technologies allow application haps the two biggest obstacles to overcome are temporal of FeSO 4 ·H 2 O only to areas susceptible to Fe deficiency. Employing and spatial variability. Temporal variability can be inthese technologies provides a practical solution to the spatial heterogeduced by variability in climatic conditions that affect soil neity of Fe deficiency in irrigated corn and increases the probability temperature and soil moisture and cause inconsistent of crop response to the fertilizer application.treatment responses. Spatial heterogeneity creates problems because Fe-deficient areas in a field are usually small and levels of plant-available soil Fe can vary within

Iron Nutrition in Field Crops

“…Liquid solutions containing low rates of chelated or non-chelated Fe are often used to temporarily correct Fe deficiencies (Anderson, 1982;Godsey et al, 2003;Goos and Johnson, 2000;Mengel, 1995;Pestana et al, 2001;Randall, 1981;Reed et al, 1988;Zaiter et al, 1992). If these materials are applied in a fashion that results in adherence to leaf surfaces, the Fe is absorbed for use by the plant (Mengel, 1995).…”

Physiological and Biochemical Evaluation of Fe-Efficiency in Fe-Deficient Maize Genotypes

“…Fe deficiency can reduce maize grain yield by as much as 20% (Godsey et al, 2003). Correcting Fe deficiency through soil amendments and foliar sprays of Fe has been partially successful considering the fact that low availability rather than low total amount usually limits Fe uptake by plant roots.…”

Delineating site-specific management zones for pH-induced iron chlorosis

“…The most effective stable iron chelate, FeEDDHA (ferric ethylenediamine di(o-hydroxyphenylacetate) currently costs about $69 ha -1 for a single soil or foliar treatment to provide 4.5 kg Fe ha -1 . Godsey et al (2003) observed that FeSO 4 . 7H 2 O seed row application increased maize yield on soil with a high pH.…”

“…Soil composition, environmental factors, and plant iron deficiency response mechanisms influence the incidence of iron chlorosis. However, the key underlying cause of iron deficiency on calcareous soil is limited iron uptake and subsequent translocation and utilization within plants because of the high bicarbonate ion concentration in the soil (Godsey et al 2003;Mengel 1994). The primary effects of bicarbonate are the neutralization of the H + ion in the rhizosphere, the reduction of plasma membrane activity of roots and an increase in root internal pH (Loeppert et al 1994).…”