Author(s): OLIVEIRA, S. M. de; PIEROZAN JUNIOR, C.; LAGO, B. C.; ALMEIDA, R. E. M. de; TRIVELIN, P. C. O.; FAVARIN, J. L.

Summary: Soybean [Glycine max (L.) Merr.] grain yield is closely associated with the level of optimal nitrogen (N) supply, especially during the reproductive stages. Foliar fertilization with low rates of N have been considered as a strategy for furnishing additional N and enhancing grain yields. Field studies using 15N tracer were conducted over two growing seasons to investigate the impact of foliar N fertilization on grain yield, plant N content, the amount of N derived from fertilizer (NDFF) and N recovery efficiency (NRE). Four foliar N rates (0, 1300, 2600 and 3900 g ha?1) were supplied by two equal split applications at the R1 and R3 stages. Foliar N fertilization of soybean canopies did not affect grain yield, grain N content, shoot N content nor plant N content. Total NDFF was increased from 0.7 to 2.0 kg ha?1 across the N rates. Nonetheless, NRE was unaffected by foliar N fertilization, which averaged 53 %. Soybean plants allocated the same amount of N fertilizer to both grains and shoots. No significant effects of low rate foliar N fertilization were registered on soybean grain yield nor plant N content, despite considerable N fertilizer recovery by plant organs.

Publication year: 2019

Types of publication: Journal article

Unit: Embrapa Fisheries and Aquaculture

Keywords: Fertilizante Nitrogenado, Foliar application, Glycine Max, Nitrogen fertilizers, Nitrogênio, Soja, Soybeans