Structural and Fractal Dimensions are Reliable Determinants of Grain Yield in Soybean

Soybean [Glycin max (L.) Merr.] plants grown under five management strategies differed significantly in their geometric structures, and were classified with 75 to 100% correct classification, based on differences in their fractal dimension (Do), midday differential canopy temperature (dT), and canopy light penetration [Log(UIo)]. Single soybean plants grown under a conventional system using moldboard tillage developed 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). Across management strategies, Do of single plants was a function of stem perimeter, circularity, and volume, and plant dry weight; whereas grain yield m was a function of Do, plant dry weight and volume, and stem circularity. 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.