Phenotypic Plasticity and Fractal Dimension are Strong Determinants of Grain Yield in Soybean

We measured growth and development variables on single soybean [Glycin max (L.) Merr.] plants under five management strategies in the upper Midwestern USA. Plants grown under different management strategies differed significantly in their geometric structures, and were classified into their proper categories with 75 to 100% correct classification, based mainly on differences in their fractal dimension (Do), midday differential canopy temperature (dT), and canopy light penetration [Log(I/Io)]. A conventional system with moldboard tillage created the most ideal microenvironment for single soybean plants to develop complex geometric structures, with significantly larger Do (1.477) values and grain yield (11.2 g per plant) as compared to plants grown under an organic system with strip tillage (Do =1.358, and grain yield = 2.32 g per plant). Knowledge of how plants respond to single and multiple management strategies will help agronomists develop better predictive models and will help farmers refine management practices to optimize yield.