Leaching of N derived from the soil and from [(15NH4) 2SO4] fertilizer during the growth cycle of bean plants

• Autor(a) principal: Caballero, Segundo S. Urquiaga
• Data de Publicação: 2014
• Outros Autores: Libardi, Paulo Leonel, Reichardt, Klaus, Moraes, Sérgio O., Victória, Reynaldo L.
• Tipo de documento: Artigo
• Idioma: por
• Título da fonte: Pesquisa Agropecuária Brasileira (Online)
• Texto Completo: https://seer.sct.embrapa.br/index.php/pab/article/view/14652
• topic: Phaseolus vulgaris; leaching of nitrogen; ammonium sulphate; use of 15N; Phaseolus vulgaris; solução do solo; sulfato de amônio; uso de ISN

In an Oxic Paleudalf ("Terra Roxa Estruturada") soil located in Piracicaba, São Paulo, the dynamics of soil total-N and N derived from fertilizer (ammonium sulphate - 15N) in the soil solution during a bean (Phaseolus vulgaris, L.) crop 'Carioca' growth in the Autumn period (April-July), was studied. Nitrogen losses due to leaching beyond 120cm of depth were estimated. The crop was fertilized with 42 kg/ha of N using ammonium sulphate, highly enriched with 15N (56,111% 15N atoms). The fertilization was made in two stages: 1/3 was applied six days after germination (DAG) and the rest 26 DAG. The soil solution was sampled in situ, using extractors placed in the following depths of profile: 45 cm, 75 cm, 105 cm and 135 cm. The samples were accumulated during each of five periods of 20 days (0-6, 6-2 26-46, 46-66 and 66-86 DAG). In these samples the total-nitrogen was determined, and percentage 15N atoms to determine the N derived from fertilizer. It was found that: 1) during the cropping period the average total-nitrogen concentration and N derived from fertilizer decreased markedly with soil depth, being very small (15 ppm and 0,048 ppm, respectively) at 105/135 cm of depth and, 2) during the crop development under minimal drainage conditions only 3 g/ha of total nitrogen and 3.04 mg/ha of N derived from fertilizer were leached beyond the 120 cm of depth.