Data/hora: 03/06/2024 07:02:02

Biblioteca(s): 	Embrapa Cerrados.	
Data corrente: 	13/12/1999	
Data da última atualização: 	13/12/1999	
Autoria: 	HUNTINGTON, T. G.	
Título: 	The influence of tillage, inoculation and the regulation of symbiotic nitrogen fixation on the production of field beans and the mineralization of nitrogen from winter annual cover crops.	
Ano de publicação: 	1984	
Fonte/Imprenta: 	Lexington: University of Kentuchy, 1984.	
Páginas: 	158p.	
Idioma: 	Inglês	
Notas: 	Ph. D. Thesis.	
Conteúdo: 	Field experiments were established at several locations in the. Dominican Republic in 1982 and 1983. Initial experiments evaluated the no-tillage cropping system in this subtropical invironment. Subsequent experiments examined the response of beans (Phaseolus vulgaris) to inoculation with improved strains of Rhizobium phaseoli and determined the influence of tillage and phosphorus fertilization on the inoculation response. The effectiveness of indigenous strains of Rhizobium phaseoli was compared with commercial inoculant and nitrogen fertilizer by evaluating the growth response of Phaseolus vulgaris in the greenhouse. Further investigations were designed to probe the limitatios to nitrogen fixation inherent in this association. The age-nitrogenase enzyme activity profiles of different host/endophyte combinations were characterized to distinquish wether temporal  regulation or fixation rate was the primary limiting factor. An analysis of nitrogen mineralization from killed winter annual cover crops and subsequent nitrogen recovery by no-till corn was made in Princeton, Kentucky in 1982. Initial experiments in the Dominican Republic have demonstrated the adaptability of the no- tillage system to various soil and climact conditions. Grain yelds of red beans were not influenced by inoculation with Rhizobium. The response to inoculation was not influenced by tillage or phosphorus. It is tentatively concluded that this cultivar of P. vulgaris forms an ineffective symbiotic association with the limitations to fixation being genetic rather than envirommental. A wide range in fixation effectiveness between indigenous strains of R. phaseoli was observed. The most effective strains were asignificantly less effective than nitrogen fertilizer in supplying plant nitrogen requirements. Variability was observed between bean types in age- activity profile and the proportion of nitrogen fixation occurring after flowering sggesting the importance of temporal regulation of nodule activity in the effectivenes of different bean types. Comparisons btween effective and ineffective strains indicated that fixation rate was the most important factor controlling effectiveness between strains. In the study of nitrogen mineralization from winter annual cover crops it was demonstrated that the majority of nitrogen released during the corn growing season became available after corn silking, suggesting  the potential for enhanced synchronization through careful management.	
Palavras-Chave: 	Cultivo de inverno; Winter crops.	
Thesagro: 	Cultivo do Solo; Feijão; Fixação de Nitrogênio; Inoculação; Manejo do Solo; Mineralização; Phaseolus Vulgaris; Rhizobium; Simbiose.	
Thesaurus Nal: 	inoculation methods; kidney beans; mineralization; nitrogen fixation; symbiosis; tillage.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Cerrados (CPAC)	
Exemplares: 	CPAC - (16076-1) - ADD - TS - -- - T025/84 - HUN - T025/84 - DIS