The importance of early dry matter and nitrogen accumulation in soybean yield

• Published in: European journal of agronomy 1998-06, Vol.9 (1), p.1-10
• Main Authors: Koutroubas, S.D, Papakosta, D.K, Gagianas, A.A
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; ammonium nitrate; ammonium sulfate; application rate; Biological and medical sciences; Bradyrhizobium japonicum; crop growth stage; crop yield; Dry matter; dry matter accumulation; dry matter partitioning; Economic plant physiology; filling period; Fundamental and applied biological sciences. Psychology; Glycine max; harvest index; Inoculation; N accumulation; N redistribution; nitrogen; nitrogen content; Nitrogen metabolism and other ones (excepting carbon metabolism); nutrient transport; nutrient uptake; Nutrition. Photosynthesis. Respiration. Metabolism; plant development; pods; root nodules; seed inoculation; seed weight; seeds; Soybean; split application; Yield
• ISSN: 1161-0301; 1873-7331
• DOI: 10.1016/S1161-0301(97)00067-1

A field study was conducted to assess the effect of inoculation and N fertilizer on the amount of dry matter and N accumulation and redistribution in soybean [ Glycine max (L.) Merrill], and to examine their association with yield. The soybean cultivar Williams was grown in a silty clay (Typic Xerorthent) soil, free of Bradyrhizobium japonicum, in 1992 and 1993. Soybean seeds were inoculated at planting with commercial peat inoculant. Nitrogen fertilizer at rates of 0, 120 and 240 kg ha −1 was applied, half before planting and half at full bloom (R2). Plant samples were taken at full bloom, beginning of seed growth (R5), and maturity (R8). Seed yield was not affected by N application, while it was increased by inoculation. The inoculated plants accumulated more dry matter and N in vegetative tissues at the R2 and R5 stages. Dry matter and N redistribution efficiency during the seed filling period were the same for inoculated and uninoculated plants. Seed yield was positively correlated with dry matter at R2, vegetative dry matter and N content at R5, and redistributed nitrogen. Results indicate that the accumulation of dry matter and N at early growth stages is an important factor in attaining high yields.