With higher seed cost and lower commodity prices, there are many questions about optimizing soybean seeding rates and variable rate soybean planting. This presentation will discuss results of multi-year on-farm studies to identify when and where farmers can increase or decrease their normal or common soybean seeding rates. The focus will be on the predictive power of on-farm trials and the economic benefit of changing common soybean seeding rates for categories with different plant row spacing, planting dates, rainfall, soil, and field topography. Risk analysis indicates no significant effects of spatial factors on soybean yield response to higher seeding rates but higher probability of economic yield response after May 20 planting in normal years or after June 15 in years with delayed planting.
