Soybean Growth and Development in Various Management Systems and Planting Dates

Abstract

Soybean [Glycine max (L.) Merr.] has the ability to produce similar yields across a broad range of management systems and planting dates. Our objective was to better understand growth factors affecting yield component compensation in the upper Midwest under different management systems. An older cultivar, Hardin, and two newer cultivars, DeKalb CX232 and Spansoy 250, were grown in five management systems during four growing seasons from 1997 to 2000. Four of the five management systems were located near Arlington, WI, on a silt loam soil consisting of conventional and no‐tillage systems with and without irrigation. The fifth management system was located near Hancock, WI, on a conventionally tilled, irrigated sandy loam soil. Yield component compensations gave similar grain yield among cultivars, planting dates, and management systems. At R6, CX232 and Spansoy 250 averaged greater dry matter (DM) accumulation, leaf area index (LAI), and crop growth rate (CGR) than Hardin. Early planted soybean had more total DM than the late‐planted soybean. No‐tillage systems produced more total DM, LAI, and CGR after R3 than the two conventional tillage systems at Arlington. Irrigated systems had higher LAI than the nonirrigated systems. These results indicate that the compensatory growth and alterations in plant development among cultivars, management systems, and planting dates had no impact on soybean yield.