Sistemas de produção de soja com culturas anuais e de cobertura em safrinha na contribuição de produção de fitomassa e controle de plantas daninhas

• Autor(a) principal: São Miguel, Andressa Selestina Dalla Côrt
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFMT
• Texto Completo: http://ri.ufmt.br/handle/1/3595
• topic: Sistema plantio direto; Culturas de cobertura; U. ruziziensis; Digitaria horizontalis; Produtividade de grãos; CNPQ::CIENCIAS AGRARIAS::ENGENHARIA AGRICOLA; No-tillage system; Cover crops; U. ruziziensis; Digitaria horizontalis; Grain yield

The objective of the present study was to evaluate annual and cover crops sown in the second crop after soybean harvest in the production of phytomass (leaves and stems), suppression of weeds and soybean yield in succession in production systems. The experiment was conducted in the agricultural years of 2013/2014, 2014/2015 and 2015/2016, in the experimental area of the Federal University of Mato Grosso, Campus of Rondonopolis. It was implanted in a dystrophic Oxisol, in a randomized block design with nine systems in the off-season: fallow, annual crops (maize, sunflower and cowpea) and cover crops (Pennisetum glaucum, Crotalaria breviflora, Crotalaria spectabilis, Urochloa ruziziensis, Cajanus Cajan, Stylosanthes sp., Urochloa brizantha), with single treatments and intercropping, in four replications. Were evaluated the phytomass, soil cover rate and yield of annual crops in the second crop, soybean yield in the crops and weeds during the whole year. The systems with maize obtained the highest yields of grains. The systems with P. glaucum and U. ruziziensis showed establishment and growth faster than the other cover crop species, which resulted in higher dry phytomass in this period. C. spectabilis was noted in the accumulation of dry phytomass at 90 days after desiccation in relation to C. breviflora. Regarding weed control, the treatments that most influenced the reduction of weed germination or growth were U. ruziziensis single and the consortium between corn + U. ruziziensis with 100% control in most of the evaluated epochs and species. The D. horizonthalis weed species was the one that obtained the largest population among the evaluated species. P. glaucum and U. ruziziensis single showed more efficient establishment and growth of plants, resulting in higher total biomass and soil cover rate in the agricultural year of 2014. In 2015, maize intercropped with U. ruziziensis and C. spectabilis, sunflower + U. ruziziensis stood out in total phytomass production during flowering and after harvesting maize and sunflower grains. The composition of the phytomass in the systems presents greater proportions of stems in relation to leaves, with highlight to C. spectabilis after senescence. The systems with U. ruziziensis, P. glaucum, C. spectabilis and consortia with maize + U. ruziziensis, sunflower + U. ruziziensis and maize + C. spectabilis are alternatives that help in the integrated management of weeds, by reducing the incidence and increasing the control of the main species that were detected during the conduction of the experiment. In the 2015/16 crop year, all production systems using annual crops and cover crops are efficient to increase soybean yield in succession, especially C. spectabilis.