Planting Date And Maturity Group Selection To Maximize Soybean Yield And Subsequent Dry Matter And Nutrient Uptake Partitioning And Removal

Download or read book Planting Date and Maturity Group Selection to Maximize Soybean Yield and Subsequent Dry Matter and Nutrient Uptake, Partitioning, and Removal written by Adam Paul Gaspar and published by . This book was released on 2016 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: As soybeans have become a major U.S. crop and key component in different cropping systems over the past half century, advancements in breeding and production practices have shown gains in yield and economic profitability for producers. Important production considerations included soil fertility, proper maturity group (MG) selection, and planting date. In southern Wisconsin, maximum yields are reduced by 21.2 kg ha-1 day-1 after May 10th (Gaspar and Conley, 2015). Growers have realized this effect and gradually shifted their soybean planting earlier. However, some believe that while producers are planting earlier and experiencing a longer growing season, they have not adequately adjusted their soybean MG’s. Coincident with earlier planting dates is the increased risk of sub-optimal stands and the need for replanting some years. Proper replanting methods (fill-in) and optimal final plant stands (>247,000 plants ha-1) have been determined by Gaspar and Conley (2015) but again, the proper MG to use in replant or essentially late planting scenarios to maximize yield and avoid fall frost damage is unclear. This document provides data demonstrating the importance of MG selection and the negative impact of delayed planting in the Northern Corn Belt. Economically and environmentally sustainable soil fertility programs are a necessity for modern soybean production systems. Unfortunately, soybean nutrient uptake and partitioning models are primarily built from work conducted in the early 1960’s with obsolete soybean genetics and production practices (Hanway and Weber, 1971a; Hanway and Weber, 1971b). Since the 1960’s, yields have nearly doubled to 2906 kg ha-1 in 2013 (USDA-NASS, 2014b) and soybean physiology has been altered with approximately one additional week of reproductive growth (Rowntree et al., 2014) and greater harvest index’s (HI) (Kumudini et al., 2001) for currently cultivated varieties. More precise and accurate estimates have the potential to increase grower profitability by applying only what the crop needs while possibly decreasing the environmental impact in terms of nutrient loads in the Mississippi watershed, which accounts for more than 90% of all US soybean acres (USDA-ERS, 2014). This document highlights large changes in nutrient uptake, partitioning, and removal of current soybean genetics and production practices.