Green manure incorporation timing for organically grown broccoli

Pesquisa Agropecuária Brasileira

Ellen Rúbia Diniz²  Ricardo Henrique Silva Santos²  Segundo Sacramento Urquiaga¹  Luiz Alexandre Peternelli¹  Tatiana Pires Barrella²  Gilberto Bernardo De Freitas² 

[1] ,Universidade Federal de Viçosa Dep. de Fitotecnia Viçosa MG ,Brazil

关键词: Brassica oleracea;    Stizolobium cinereum;    biological nitrogen fixation;    decomposition rate;    N recovery;    Brassica oleracea;    Stizolobium cinereum;    fixação biológica do nitrogênio;    taxa de decomposição;    recuperação de nitrogênio;   

DOI  :  10.1590/S0100-204X2007000200008

来源: SciELO

【 摘 要 】

The objective of this work was to determine the effect of incorporation timing of the velvet bean (Stizolobium cinereum) (GM) on both organic broccoli yield and N status. Mineral N content in the soil, biologically fixed N recovery by broccoli, GM biomass decomposition and N release kinetics were also determined. Plots were fertilized with 12 Mg ha-1 of organic compost and received GM either at 0, 15, 30 or 45 days after transplant. Other treatments were compost (12 or 25 Mg ha-1), GM, mineral fertilizers and control (no fertilizer). The data were collected in four completely randomized blocks. GM decomposition increased mineral N content in soil as rapidly as mineral fertilizer or the supply of 25 Mg ha-1 of compost. The N half-life in GM (24 days) is smaller than the mass half-life (35 days) and the biological fixation contributed with 23.6% of N present in the aboveground biomass of broccoli. The result suggests a higher synchrony between the crop relative growth rate and N release from the GM when incorporated at crop early growth stage. The incorporation of GM until 15 days after transplanting replaces 50% of the highest compost dose, without yield loss.

【 授权许可】

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