Chapters authored
Row Spacing and Seeding Rate Effects on Soybean Seed Yield
Soybean growers in the northern latitudes of the United States plant the crop in a wide range of row spacings although there has been a shift toward wider rows (>50 cm) in some Upper Midwest states in the last 5 years. The objective of this study was to evaluate the impact of row spacing and seeding rate on the performance of soybean and to determine whether these management practices interact to influence soybean yield. A row spacing study was conducted at Aberdeen and Beresford, South Dakota, USA, in 2014 and 2015. The study had two row spacings (19 and 76 cm), four seeding rates (247,000, 333,500, 420,000, and 506,500 seeds ha−1), and two soybean varieties at each location. Soybean had greater stand establishment in 19 cm rows (6–10% higher) compared with 76 cm rows. Soybean in 19 cm rows yielded 0.8–10% more than in 76 cm rows depending on the location or year. Seed yield increased with increasing seeding rate with the highest seeding rate of 506,000 seeds ha−1 yielding greatest. The increase in seed yield due to the increase in seeding rate ranged from 3 to 7%. At each location, the longer duration soybean variety yielded higher than the shorter duration variety.
Part of the book: Soybean
Agronomic Response of Camelina to Nitrogen and Seeding Rate on the Northern Great Plains
Camelina (Camelina sativa L. Crantz,) a new oilseed crop in the Brassicaceae family has favorable agronomic traits and multiple food and industrial uses. Appropriate production practices for optimal camelina yield in temperate climates of North America are lacking. This study investigated the response of camelina seed yield and quality, and agronomic traits to applied N (5 levels, 0, 28, 56, 84, 140 kg ha−1) and four seeding rates (4.5, 9, 13, 17.5 kg ha−1). Separate experiments were conducted at four environments (site-years) for N and three environments for seeding rate in South Dakota. In three of the four environments, the highest N rate increased seed yield by 30 to 60% compared to the control. The increase in seed yield with increasing N rate was linear in a high yielding environment and quadratic in a low yielding environment. Increasing seeding rate increased plant stands but had inconsistent impacts on seed yield depending on location and year. Seed oil concentration ranged from 149 to 350 g kg−1, was inversely related to N rate but was not influenced by seeding rate.
Part of the book: Nitrogen in Agriculture