Interação entre micro-organismos do solo, plantas daninhas e as culturas do milho e da soja

• Autor(a) principal: Fialho, Cíntia Maria Teixeira
• Data de Publicação: 2013
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1201
• topic: Competição; Bidens pilosa; Brachiaria decumbens; Eleusine indica; Micorriza; Competition; Bidens pilosa; Brachiaria decumbens; Eleusine indica; Mycorrhiza; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOTECNIA

The competitive ability of agriculture and weeds depends on the efficacy use of the resources from the environment. It is believed that could have relation between associations with plants species and soil microbiota and its capacity to change it, affecting the level of interference. This research evaluated causes and consequences of the interference in three species of weeds (Bidens pilosa L., Brachiaria decumbens Stapf. (Syn. Urochloa decumbens) and Eleusine indica (L.) Gaertn.) under culture of corn and soybean in two different conditions: a) weeds competing without any contact with other culture roots b) same conditions as the first but now with contact among the roots. It was set it up two experiments with soybean s and corns culture. Each culture composes an isolated experiment, so there wasn t any comparable variant in corn and soybean cultures. The species B. pilosa and E. indica when exposed in a competition with soybean culture showed higher mycorrhizal colonization and it did interfere negatively in growing aspects and accumulation of nutrients. The Inorganic phosphorus solubilization potential of the corn s rhizosphere soil submitted to a competition in contact with roots between other species raised a value of 2.58 μg by gram of soil. This contact among the roots in competition was able to contribute to a reduction of the arbuscular mycorrhizal colonization of corn s roots and increased the weeds roots colonization. In relation with soybean culture in competition with weeds, and occurred less oxidation of the organic material by unit of microbiological biomass and resulted lower metabolic quotient compared to the monoculture of soybean rhizosphere. It happened a positive interaction in soybean mycorrhizal colonization and competitive weeds independently of the species of weed and its contacts among roots. The raise of mycorrhizal colonization was 53, 40 e 33% during the competitive stage with soybean and species of Brachiaria decumbens, Eleusine indica and Bidens pilosa, respectively. The weeds showed different competitive strategies and acted as good challengers and in many cases they kept the variant stable avoiding being reduced when in competition with the cultures. It was able to conclude that the combinations among cultures and species of weeds alters in many ways the behavior of the soil microbiota the contact between the roots showed great importance during interference among the species.