Soybean Iron-Deficiency Chlorosis Tolerance and Yield Decrease on Calcareous Soils

Cultivar selection is one of the best ways to manage iron-deficiency chlorosis (IDC) problems in soybean [Glycine max (L.) Merr.]. The objective was to determine if precision farming techniques of planting IDC-tolerant cultivars in calcareous soil areas and high-yielding cultivars in non-IDC areas would increase soybean yield. We used paired sites within the same field. The sites were located in areas of a field where IDC was present and absent. The same commercial soybean cultivars were planted on the paired sites. Results showed that visual scores for IDC could not identify the highest-yielding cultivar in IDC-affected areas. If the only information available to growers is yield on non-IDC sites and visual I DC ratings, then the yield of the whole field could be increased by planting two different cultivars. If yield data from replicated performance testing of numerous different cultiars was available for I DC sites and also for non-IDC sites, then growers may be able to identify a single cultivar that has high yield across the entire field.