Ciência Rural | |
Nitrogen management in maize in no-till system in succession to winter cover crops in two locations: I - effect on N uptake | |
Beheregaray Neto, Vasco1  Rizzardi, Mauro Antônio3  Silva, Paulo Regis Ferreira da1  Argenta, Gilber2  Baruffi, Marcos João3  | |
[1] Universidade Federal do Rio Grande do Sul;Universidade Federal do Rio Grande do Sul, Porto Alegre;Universidade de Passo Fundo | |
关键词: winter cover crops; Zea mays L; | |
DOI : 10.1590/S0103-84781999000400002 | |
学科分类:农业科学(综合) | |
来源: Universidade Federal de Santa Maria * Centro de Ciencias Rurais | |
【 摘 要 】
The permanence of cultural residues on soil surface modifies the processes of immobilization and mineralization, reducing N availability to maize, especially in succession to grasses. The objective this study was to evaluate, in two locations, the effects of rate and timimg of N application in maize (0-0; 0-160; 30-130 and 60-100kg/ha, respectively, at sowing and sidedressed), in no-till system, established in two sowing dates after desiccation (1 and 20 days) of two winter cover crops (black oat and common vetch) and bare area without weeds, on N uptake. The research was conducted at two locations of the state of Rio Grande do Sul, Brazil, in the 1996/97 growing season. In Eldorado do Sul, N application at sowing was beneficial because it increased N uptake in relation to the treatment with total N sidedressed, regradless of the species of winter crop tested. At Passo Fundo, only in the stage of 3-4 leaves there was advantage of N application at sowing in relation to total sidedressed application. In the stages of 6-7 leaves, 10-11 leaves and of tasseling there were no differences among the treatments with N application. The delay of maize sowing date after desiccation in 20 days is a management practice that could be used, specially when maize follows black oat, since it increased, at the average at the N management systems, 54 e 75% N uptake, respectively in Eldorado do Sul and in Passo Fundo. N uptake by maize in succession to black oat was lower at Eldorado do Sul that in Passo Fundo, in all stages of development tested. The increment of N rate from 30 to 60 kg/ha did not increase N uptake by maize plants, regardless of cover crop in the winter.
【 授权许可】
CC BY-NC
【 预 览 】
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RO201911300100470ZK.pdf | 79KB | download |