Performance of soybean varieties differs according to yield class: a case study from Southern Brazil

Considering environmental conditions in the selection of soybean (Glycine max L.) varieties is a key strategy in ensuring high crop yield. Recently, the new technology of multi-hybrid planters has been making it more practical for farmers to plant different varieties together. However, there remains a gap in understanding how different varieties perform in terms of yield class; this knowledge is essential for technology adoption. The objectives of this study were to: (i) evaluate the agronomic performance of six soybean varieties at varying yield class (YC); (ii) quantify the economic return of within-field varieties arrangement; and (iii) propose guidelines for multi-variety soybean planting in Southern Brazil. The experimental design comprised a factorial split-plot set up in a randomized complete block design, with three YC [low (LY), medium (MY) and high yielding (HY)] and six varieties, replicated three times. The main findings were: (a) soybean variety performance differed according to YC; (b) the farmer-selected variety performed well for HY and MY; (c) varieties with high plant height (PH) should be placed in LY, where PH reduction and an increase in the number of pods and yield were recorded; (d) varieties with low PH should be placed in HY, avoiding excessive plant growth and yield penalty; (e) within-field variety arrangement increased yield by 2.10% and 11.50% and economic return by US$ 26 and 137 ha−1 for HY and LY, respectively. The results support the emergent concept of within-field multi-variety soybean planting in Southern Brazil.