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 IDC 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 IDC 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.