title: Effects of Row-Type, Row-Spacing, Seeding Rate, Soil-Type, and Cultivar Differences on Soybean Seed Nutrition under US Mississippi Delta Conditions.
abstract: The new Early Soybean Production System (ESPS), developed in the Midsouth USA, including the Mississippi delta, resulted in higher yield under irrigated and non-irrigated conditions. However, information on the effects of the agricultural practices such as row-type (RT: twin- vs. single-row), row-spacing, (RS), seeding rate (SR), soil-type (ST) on seed nutrition under the ESPS environment in the Mississippi delta is very limited. Our previous research in the Mississippi delta showed these agricultural practices altered seed nutrients in one cultivar only. However, whether these effects on seed nutrients will be exhibited by other soybean cultivars with earlier and later maturities across multiple years are not yet known. Therefore, the objective of this research was to evaluate the effects of agricultural practices and cultivar (Cv) differences on seed nutrition in clay and sandy soils under ESPS environment of high heat and drought. Two field experiments were conducted; one experiment was conducted in 2009 and 2010, and the other in 2008, 2009, and 2010 under irrigated conditions. Soybean were grown on 102 cm single-rows and on 25 cm twin-rows with 102 cm centers at seeding rates of 20, 30, 40, and 50 seeds m(-2). Two soybean cultivars (94M80 with earlier maturity; and GP 533 with later maturity) were used. Results showed that increasing seeding rate resulted in increases of protein, sucrose, glucose, raffinose, B, and P concentrations on both single- and twin-rows. However, this increase became either constant or declined at the higher rates (40 and 50 seeds m(-2)). Protein and linolenic acid concentrations were higher in GP 533 than in 94M80 on both row-types, but oil and oleic acid concentrations were in 94M80 than GP 533. Generally, cultivar GP 533 accumulated more seed constituents in seeds than 94M80. In 2010, there were no clear responses of seed nutrients to SR increase in both cultivars, perhaps due to drier year and high heat in 2010. It is concluded that RT and SR can alter seed nutrition under clay and sandy soils, especially under high heat and drought conditions as in the Mississippi delta.
authors.affiliation: Crop Genetics Research Unit, USDA-ARS, Stoneville, MS, 38776, United States of America.
authors.forename: Nacer
authors.initials: N
authors.lastname: Bellaloui
authors.affiliation: Crop Production Systems Research Unit, USDA-ARS, Stoneville, MS, 38776, United States of America.
authors.forename: Herbert A
authors.initials: HA
authors.lastname: Bruns
authors.affiliation: Biological Control of Pests Research Unit, USDA-ARS, Stoneville, MS, 38776, United States of America.
authors.forename: Hamed K
authors.initials: HK
authors.lastname: Abbas
authors.affiliation: Crop Genetics Research Unit, USDA-ARS, Jackson, TN, 38301, United States of America.
authors.forename: Alemu
authors.initials: A
authors.lastname: Mengistu
authors.affiliation: Crop Production Systems Research Unit, USDA-ARS, Stoneville, MS, 38776, United States of America.
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Fisher
authors.affiliation: Crop Production Systems Research Unit, USDA-ARS, Stoneville, MS, 38776, United States of America.
authors.forename: Krishna N
authors.initials: KN
authors.lastname: Reddy
mesh_terms: D057914:Agricultural Irrigation; D000069599:Crop Production / Q000379:methods*; D008922:Mississippi; D012639:Seeds / Q000235:genetics / Q000378:metabolism*; D012987:Soil / Q000737:chemistry*; D013025:Glycine max / Q000235:genetics / Q000254:growth & development* / Q000502:physiology
chemical_list: D012987:Soil