Effect of nitrogen fertilization on soil microbial biomass in an Oxisol cultivated with irrigated barley in the Brazilian Cerrado

Acta Agronómica

Renato Fernando Amabile¹  Walter Quadros Ribeiro Junior¹  Lidia Tarchetti Diniz²  Bruno Tarchetti Diniz²  María Lucrecia Gerosa Ramos²  Andre Freire Cruz³  Leonice Vieira de Franca⁴ 

[1] Embrapa, Empresa Brasileira de Pesquisa Agropecuária. Ministério da Agricultura, Pecuária e Abastecimento, Brasil;Faculdade de Agronomia e Medicina Veterinária – FAV, Universidade de Brasília – UnB, Brasília, DF, Brasil;Kyoto Prefectural University, Graduate School of Life and Environmental Sciences, 1-5 Shimogamohangi-cho, Sakyo-ku, Kyoto 606-8522, Japan;Universidade de Brasilia. Facultade de Agronomia e Medicina Veterinaria, Campus Universitário Darcy Ribeiro, Brasília, Brasil;

关键词: Cerrado;    Hordeum vulgare L.;    Microbial biomass;    Nitrogen;    Soil quality;   

DOI  :  10.15446/acag.v65n2.46432

来源: DOAJ

【 摘 要 】

The aim of this study was to evaluate the effect of different nitrogen doses and five period of sample collection, on soil microbial biomass - nitrogen (SMB-N), total nitrogen (total N) and percentual ratio of the microbial biomass and total N (SMB-N/total N) in a Oxisol cultivated with barley (Hordeum vulgare L.). The experiment was installed in June, 2005, in an area located at Embrapa Cerrados, Federal District. The experimental design was a randomized block, with three plots received doses of nitrogen: 20 – 40 – 80 kg ha-1 N and a control without it and the subplots were period of soil sample. Three applications of N were realized: 10 kg ha-1 on the 5th day (06/14) after sowing; the rest of N was parceled in two applications with fertigation, on tillage, on the 27th (07/08) DAP, e no 43rd (07/22) DAP. Soil samples layer (0 - 10 cm deep) were collected for (SMB-N) determination and total N in six periods: 02 days before of the first fertigation; 02 days after of the first fertigation; 04 days before of the last fertigation and 04 days after of the last fertigation; on flowering stage and after harvesting. There was effect of the doses of N and the period of soil collection on the SMB-N, total N and in the ratio SMB-N/ total N. The average values of total N revealed steadier in short-term (cycle of the culture) and this was not a good parameter to evaluate the behavior and N transformations in the soil-plant system.

【 授权许可】

Unknown