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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Soybean Seed Treatment with Nickel Improves Biological Nitrogen Fixation and Urease Activity

Texto completo
Lavres, Jose [1] ; Franco, Guilherme Castro [1] ; de Sousa Camara, Gil M. [2]
Número total de Autores: 3
Afiliação do(s) autor(es):
[1] Univ Sao Paulo, Ctr Nucl Energy Agr, Piracicaba - Brazil
[2] Univ Sao Paulo, Luiz de Queiroz Coll Agr, Dept Crop Sci, Piracicaba - Brazil
Número total de Afiliações: 2
Tipo de documento: Artigo Científico
Citações Web of Science: 9

Nickel (Ni) is an essential micronutrient required for plants' metabolism due to its role as a structural component of urease and hydrogenase, which in turn perform nitrogen (N) metabolism in many legume species. Seed treatment with cobalt, molybdenum and Bradyrhizobium strains has been widely practiced to improve crops. Additionally, seed treatment together with Ni fertilization of soybean might improve the efficiency of biological nitrogen fixation (BNF), boosting grain dry matter yield, and N content. The objective of this study was to evaluate the effect of soybean seed treatment with Ni rates (0, 45, 90, 135, 180, 360, and 540 mg kg(-1)) on BNF, directly by the N-15 natural abundance method (delta N-15 parts per thousand) and by measurement of urease {[}E.C.] activity, as well as indirectly by nitrogenase (N-ase) activity {[}E.G.]. Soybean plants (cultivar BMX Potencia RR) were grown in a sandy soil up to the R7 developmental stage (grain maturity), at which point the nutrient content in the leaves, chlorophyll content, urease, and N-ase activities, Ni and N content in the grains, nodulation (at R1-flowering stage), as well as the contribution of biological nitrogen fixation (BNF; delta N-15 parts per thousand) were evaluated. The proportion of N derived from N-2 fixation varied from 77 to 99% using the natural N-15 abundance method and non-nodulating Panicum miliaceum and Phalaris canariensis as references. A Ni rate of 45 mg kg(-1) increased BNF by 12% compared to the control. The increased N uptake in the grains was closely correlated with chlorophyll content in the leaves, urease, and N-ase activities, as well as with nodulation. Grain dry matter yield and aerial part dry matter yield increased, respectively, by 84 and 51% in relation to the control plants at 45 mg kg(-1) Ni via seed treatment. Despite, Ni concentration was increased with Ni-seed treatment, Ni rates higher than 135 mg kg(-1) promoted negative effects on plant growth and yield. In these experimental conditions, seed treatment with low Ni rates caused higher dry matter yield of plants and grains, N content in the grains, and in the aerial part by increasing of BNF. (AU)

Processo FAPESP: 07/58406-1 - Avaliação da disponibilidade do níquel no solo por métodos químicos e biológico
Beneficiário:José Lavres Junior
Linha de fomento: Bolsas no Brasil - Pós-Doutorado