Controle de plantas espont?neas e aporte de nitrog?nio em ?rea cultivada com cafeeiro atrav?s do manejo de plantas de cobertura de solo

• Autor(a) principal: Freitas, Raony Alyson de
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/jspui/2583
• topic: Coffea arabica L.; Plantas de cobertura; Ervas espont?neas; Coffea arabica L.; cover plants; weeds.; Agronomia

Brazil is the world's largest coffee producer (Coffea arabica L.), accounting for more than 30% of the international market. This activity is a great employment generator and promotes development in rural areas. It is estimated that expenditures with fertilizers and correctives represent 30% of the total cost of coffee production, where nitrogen fertilizers are the most important. The production of organic coffee would be an alternative for the family farmers in the Zona da Mata of Minas Gerais. Some production costs could be reduced by the practice of green manuring, which is considered a good strategy to enhance the availability of nitrogen in organic systems, since green manures in coffee crops improves the physical, chemical and biological characteristics of the soil, raises the nutrient contents in coffee leaves, controls nematodes, incorporate N via NBF, increases mycorrhization, concentrates nutrients in the more superficial layers of the soil besides controlling weeds. The prior knowledge of the floristic composition of weeds in organic coffee cultivation systems allows one to anticipate the organization of preventive strategies for the adoption of more sustainable control measures. The objective of this work was to evaluate the effect of different species of green manure in intercropping or single cultivation systems on the control of spontaneous weeds and on the nitrogen input in coffee cultivation in agroecological conversion. The experiment was carried out in an arabica coffee crop with cv. Catua? Vermelho in the city of Cajuri, located in the region of the Zona da Mata of Minas Gerais, using an experimental design with randomized blocks with five replicates. Four treatments were used: a) Canavalia ensiformis in single cultivation; B) Crotalaria juncea L. in single cultivation; C) Crotalaria juncea L. intercropped with Canavalia ensiformis; and d) control (spontaneous vegetation). Twenty-one species of weeds were identified in the experimental area, distributed in nine families, in which the main species were, as follows: Acanthospermum hispidium; Commelina benghalensis; Ageratum conyzoides, Digitaia sanguinales, Brachiaria plantaginea, Ischaemum rugosum. At the end of the experiment, it was observed that the highest values in the dry biomass production were associated to the treatments formed by the Crotalaria juncea L. intercropped with Canavalia ensiformis. Fallow produced much less dry biomass than the other treatments. Green manures were approximately 4 to 11 times more efficient in accumulation of N compared to weeds. Cover plants altered the population dynamics of weeds, significantly reducing their infestation in the experimental area. The treatment with Canavalia ensiformis was efficient in controlling more than 71% of the species found in the experimental area. The species Ageratum conyzoides, which belongs to the family Asteraceae, was the most frequent, the densest, the most abundant and the predominant in the area, where all treatments with cover crops presented difficulties in controlling it.