Influence of Maturity Group, Row Pattern, and Seeding Rate on Soybean Grown on Silt Loam Soils.

Significant changes in the agriculture landscape have occurred in the lower Mississippi River Alluvial-flood plain. A large portion of silt loam soils have shifted from cotton to soybean production. Due to this change, research initiatives are focusing on several key agronomic issues associated with growing soybean on silt loam soils. This research focuses on the influence of row pattern (twin-row vs. 102 cm rows), maturity group (MG IV vs. V), and seeding rate across row pattern and MG. Six different seeding rates and a late MG IV and early MG V soybean variety were included. Stand count, plant height, NDVI, leaf area index, pod count, node count, seed weight, and yield data were collected in 2009 and 2010. Seed rate had no influence on yield due to ‘the plants’ ability to compensate for lower plant populations. In 2009, the early MG V variety yielded a mean of 5132 kg ha^-1, whereas the late MG IV variety yielded significantly lower at 4155 kg ha^-1. In 2010, the early MG V yielded 5066 kg ha^-1, whereas the late MG IV variety yielded a mean of 4547 kg ha^-1 Row pattern contributed to yield differences as well; in 2009, the twin row pattern enjoyed a mean of 4873 kg ha^-1, whereas the single row pattern had a significantly lower mean of 4414 kg ha^-1. Yield differences were also observed in 2010 with regard to row pattern; single row pattern had a mean of 4604 kg ha^-1 while twin row pattern yielded 5008 kg ha^-1. Higher NDVI values were collected from plants in the twin-row system and MG V variety. This MG and row pattern contribution to NDVI differences is due to the ability of the MG V variety to shade the row middles quicker and resulted in increased leaf area. These data will prove useful in providing lower Mississippi flood plain soybean producers assistance with agronomic decisions.