Mineral nitrogen fertilization effects on lettuce crop yield and nitrogen leaching

Autor(es)

Sylvestre, Thiago de Barros ^[1] ; Braos, Lucas Boscov ^[2] ; Batistella Filho, Felipe ^[3] ; Pessoa da Cruz, Mara Cristina ^[2] ; Ferreira, Manoel Evaristo ^[2]

Afiliação do(s) autor(es)

^[1] Mosaic Brasil, Av Roque Petroni Jr 999, BR-04707910 Sao Paulo - Brazil

^[2] Univ Estadual Paulista, UNESP, Fac Ciencias Agr & Vet, Dept Solos & Adubos, Via Acesso Prof Paulo Donato Castellane S-N, BR-14884900 Jaboticabal - Brazil

^[3] Fed Inst Educ Sci & Technol Sao Paulo, Campus Matao R Estefano Davassi 625 N, BR-15991502 Matao - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Scientia Horticulturae; v. 255, p. 153-160, SEP 20 2019.
• Citações Web of Science: 0

Resumo

The low efficiency of N fertilization in soils used to grow vegetables and the consequent need to add high levels of the nutrient are the major cause of nitrate contamination of groundwater and freshwater, which calls for practices to increase N fertilization efficiency in these crops. Two experiments were carried out in Jaboticabal, Brazil, to evaluate the effects of topdressing N fertilization on crisphead lettuce (Lactuca sativa) yield, nitrate accumulation in plant shoots, and soil nitrogen leaching in two growing seasons, summer and winter. Both experiments were designed as randomized blocks with seven treatments and five replications (35 plots). The treatments were seven different rates of topdressing N. The rates of N application were 0, 30, 60, 90, 120, 150, and 180 kg N ha(-1) in the form of urea, applied 8 (20%), 16 (40%), and 24 (40%) days after transplanting. Lettuce was harvested 34 and 42 d after transplanting in the summer and winter, respectively. Plant nitrate concentrations were determined in thy matter. After the harvest, soil samples were collected at the 0-20, 20-40, and 40-60 cm layers to quantify nitrogen in the forms of ammonium and nitrate. The data were submitted to analysis of variance and nonlinear regression analysis. Better use of topdressing nitrogen fertilization for lettuce growth was observed at rates lower than 60 kg N ha(-1). Rates of N up to 180 kg N ha(-1) did not elevate lettuce nitrate concentrations over the levels allowed for consumption but increased the amount of nitrogen lost through leaching. Decreasing N rates resulted in a similar yield and lower nitrogen leaching, improving both the environmental and economic aspects. (AU)

• Processo FAPESP: 08/52415-1 - Adubacao nitrogenada para alface: producao, acumulo de nitrato na parte aerea e mobilidade do ion no solo.
• Beneficiário: Thiago de Barros Sylvestre
• Modalidade de apoio: Bolsas no Brasil - Mestrado