Comparison of Field Management Strategies for Preventing Iron Deficiency Chlorosis in Soybean

Abstract

Iron deficiency chlorosis (IDC) is a serious management issue for soybean [Glycine max (L.) Merr.] grown on calcareous soils. Strip trials were established on calcareous Mollisols to study the effects of Fe-ethylene diamine-N,N¢-bis (hydroxy phenyl) acetic acid (EDDHA) in-furrow (IF-Fe) and of an oat (Avena sativa L.) companion crop on two soybean varieties either tolerant or susceptible to IDC. The severity of IDC varied from low to severe within sites. The susceptible variety produced the highest yield in the absence of IDC. In-furrow Fe increased the yield of a variety susceptible to IDC under moderate to severe IDC. The oat companion crop increased yield consistently for the susceptible variety under severe IDC and sometimes reduced yield when oat grew beyond 25 cm in height. The tolerant variety without IDC management produced yields similar to those of the susceptible variety with IF-Fe or an oat companion crop. Oat reduced trifoliate nitrate N and Fe concentration regardless of IDC severity. Trifoliate Fe concentration lowered with IF-Fe, but only when oat was not planted. Grain protein and oil concentration were affected by variety, but were not affected by IDC management. Soil test factors such as soil organic matter (SOM), pH, electrical conductivity (EC), or diethylene triamine phentaacetic acid Fe (Fe-DTPA ) were poor predictors of the severity of IDC. Variety selection is the most important strategy for lessening the severity of IDC. In-furrow application of Fe-EDDHA provides a solution for mitigating moderate to severe IDC and provides less risk than an oat companion crop.

Physiological Regulation Associated with Differential Tolerance to Iron Deficiency in Soybean

“…In this study, a logistic equation analysis indicated that the classification of soybean genotypes with differential tolerance to Fe deficiency is relative and not absolute in accordance with the study conducted by Liesch et al (2011). The ability of plants to withstand stress is determined not only by their own characteristics but also by the stress level (Kaiser et al, 2014).…”

Iron Availability and Management Considerations: A 4R Approach

“…Overall, considering both soil test DTPA‐Fe and soluble salts (electrical conductivity) when screening varieties for chlorotic iron deficiency symptoms in the North‐Central region was recommended (Hansen et al., 2003). This is consistent with other Minnesota research reporting that yield of iron‐deficiency‐susceptible varieties was correlated with soil pH, DTPA‐Fe, electrical conductivity, and soil organic matter at a 6‐inch depth (Kaiser et al., 2014). With such dynamic soil properties influencing iron availability, optimizing iron nutrition is difficult and, in most cases, utilizing practices that inform the 4Rs such as soil tests, plant analysis, and yield maps together when putting a plan together pays dividends.…”

Complete Issue

“…Overall, considering both soil test DTPA-Fe and soluble salts (electrical conductivity) when screening varieties for chlorotic iron deficiency symptoms in the North-Central region was recommended (Hansen et al, 2003). This is consistent with other Minnesota research reporting that yield of iron-deficiency-susceptible varieties was correlated with soil pH, DTPA-Fe, electrical conductivity, and soil organic matter at a 6-inch depth (Kaiser et al, 2014). With such dynamic soil properties influencing iron availability, optimizing iron nutrition is difficult and, in most cases, utilizing practices that inform the 4Rs such as soil tests, plant analysis, and yield maps together when putting a plan together pays dividends.…”

“…Iron fertilizers protected with an organic chelate can be effectively applied to soils to correct plant deficiencies. Chelated fertilizers such as Fe-EDDHA (Kaiser et al, 2014;Gamble et al, 2014) have been used with reasonable effectiveness, but their cost may be prohibitive for whole-field applications. Gamble et al (2014) found a soybean yield increase Iron deficiency in maize.…”

“…This acidification can be done for the entire field, or spot treatment of a portion of the root zone is often sufficient to improve iron availability in the right place. Companion crops have also been shown to be effective at reducing soil and tissue NO 3 in soybean, lowering IDC severity, and increasing yield for IDC-susceptible varieties, but termination timing can provide management difficulties (Kaiser et al, 2014).…”