Contribuição do N proveniente de partes de adubos verdes em cultivos sucessivos

• Ano de defesa: 2012
• Autor(a) principal: Vargas, Thiago de Oliveira
• Orientador(a): Santos, Ricardo Henrique Silva
• Banca de defesa: Oliveira, Teógenes Senna de , Barrella, Tatiana Pires , Puiatti, Mário
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Fitotecnia
• Departamento: Plantas daninhas, Alelopatia, Herbicidas e Resíduos; Fisiologia de culturas; Manejo pós-colheita de
• País: BR
• Palavras-chave em Português: Técnicas isotópicas; 15N; Nitrogênio; Leguminosas; Sistema radicular; Efeito residual
• Palavras-chave em Inglês: Isotopic techniques; 15N; Nitrogen; Legumes; Root system; Residual effect
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA
• Link de acesso: http://locus.ufv.br/handle/123456789/1188

Three experiments were conducted. Experiments 1 and 2 was to evaluate the effect of root, shoot and whole plant of sunnhemp (Crotalaria juncea) and jack bean (Canavalia ensiformis) in supplying N to the cabbage crop (Brassica oleracea var. capitata) determining the transfer of legume-N and the fertilizer value of green manure (A Value). The third experiment aimed to evaluate the efficiency of N utilization in growing broccoli in succession zucchini-corn under doses of green manure Crotalaria juncea, labeled with 15N. The first experiment was conducted in pots in the greenhouse and the other two in the field. Experiments 1 and 2 consisted of seven treatments in factorial (2x3) +1, 2 species of legume and 3 plant parts (root, shoot and whole plant) and 1 additional treatment (50% of mineral fertilizer of N recommended dose). The principle of the A Value was used to obtain the fertilizer value and transferring the N-portion of each legume plants. Experiment 3 consisted of the study of the effect of residual N from green manure carried on a system of crop succession organized into three crops. The first crop was the cultivation of broccoli, the second and third crops consisted of zucchini and corn, respectively. Three treatments were established corresponding to green manure doses of 3, 6 and 9 t ha-1 at a dry matter basis, with addition of 12 t ha-1 compost in a dry matter basis. The determination of the efficiency of N utilization of sunnhemp in the crops was based on the principle of isotopic dilution. In experiments 1 and 2, the transfer of legume-N and fertilizer value from whole plant (45,06% and 159,26 kg ha-1 as N-urea) was greater than shoot (24,93% and 63,25 kg ha-1 as N-urea), which in turn was higher than the legumes-N in cabbage grown on the roots of legumes (17,87% and 40,07 kg ha-1 in the form N-urea) in pots. Cabbage plants cultivated in the field on the roots of legumes had negative values for legume-N transfer (-13,59% for sunnhemp and -3,51% for jack bean) and -18,62 kg ha-1 for fertilizer value. Under field conditions, the shoot and whole plant showed high levels of transfer of legumes-N (C. juncea, shoot = 24,35% and 24,46% = whole plant and C. ensiformis, shoots = 13,53% and whole plant = 18,53%) and for fertilizer value (shoot= 76,33 and whole plant= 96,47 kg ha-1 as N-urea). In experiment 3, the % of N in broccoli, zucchini and corn from the green manure obtained at the highest dose of green manure was 74,39; 47,42 and 19%, respectively. The amount of N in broccoli, zucchini and corn from the green manure, increased with increasing doses of applied green manure, reaching values of 58,82; 31,95 and 9,98 kg ha-1 at the highest tested dose, respectively. In pot cultivation (experiment 1), the highest fertilizer value and legumes-N transfer for cabbage cultivation were obtained with the application of the whole plant. The roots of legumes have the lowest fertilizer value and result in less transfer of legumes-N for growing cabbage. The species of green manure had similar fertilizer value. In field cultivation (experiment 2), the shoot or whole plant legumes parts resulted in higher values of legume-N transfer and fertilizer value. Roots of legumes resulted in zero content of legume-N in cabbage. In experiment 3, the largest fraction of residual N sunnhemp was used obeying the sequence of crops broccoli, zucchini and corn, and the recovery of N from green manure was 28,50% for broccoli, 16,22% for zucchini and 5,58% for corn. A total recovery of 50,3% of N from Crotalaria juncea green manure.