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URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352
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Resultados da Pesquisa
Item Soil enzymatic activity under coffee cultivation with different water regimes associated to liming and intercropped brachiaria(Universidade Federal de Santa Maria, 2022) Rodrigues, Raquel Nogueira; Reis Junior, Fábio Bueno dos; Lopes, André Alves de Castro; Rocha, Omar Cruz; Guerra, Antônio Fernando; Veiga, Adriano Delly; Mendes, Ieda de CarvalhoThis research evaluated the effects of coffee cultivation with two different water regimes associated or not with liming and the presence/absence of brachiaria as intercrop on the activities of the soil enzymes β-glucosidase, arylsulfatase and acid phosphatase. The study was carried out at the experimental farm of Embrapa Cerrados, using the cultivar IAC 144 (Coffea arabica L.), under a clayey dystrophic Cerrado Oxisol. Two water regimes (WR) were considered, WR1 with irrigation shifts throughout the year and WR3 with controlled water stress, for about 70 days, in the dry season. In each water regime, effects of lime application (with/without) and the presence/absence of brachiaria cultivated between the lines of coffee plants were evaluated. The activities of the enzymes β-glucosidase, arylsulfatase and acid phosphatase were evaluated during the rainy and dry seasons. Liming and intercropped brachiaria positively affected the activities of the three enzymes assessed in this study at varying degrees, depending on season and/or the WR. Our findings evidenced that intercropped brachiaria in coffee rows was the factor that most positively impacted soil enzymes activ ities.Item Models identity generated in neutron probe calibration in latosol cultivated with coffee and signalgrass(Editora UFLA, 2018-10) Borges, Inácio Barbosa; Rocha, Omar Cruz; Malaquias, Juaci Vitória; Fagioli, Marcelo; Sá, Marcos Aurélio Carolino de; Guerra, Antônio FernandoThe cover plants affects soil spatial variability interfering with soil moisture and density, leading to doubts about the need for calibration of the neutron probe for different management systems. The objective of this study was to evaluate the Model Identity Method in the verification of equality of linear regressions resulting from the calibration of a neutron probe for different layers, as a function of signalgrass management as a cover crop between rows of soil coffee crop in the Brazilian Central Cerrado. Aluminum tubes were installed to access the probe and two saturation basins were built in a coffee area, irrigated by a central pivot, in an Oxisol, with two management systems, T (Traditional with bare soil) and Sg (Signalgrass in the row). Samples were taken at depths of 0-0.20; 0.20-0.40; 0.40-0.60; and 0.60-0.80 m for determination of gravimetric moisture and density, and the volumetric moisture was determined to follow the drying of the soil. Concomitantly, measurements were taken with the neutron probe in these layers. Two calibration curves were constructed for each layer, which were compared by the above method. It was observed that treatment Sg yielded differences in soil water storage in the 0.20- 0.40 m layer, differing from treatment T. The statistical method allowed the observation of equality of regressions between treatments Sg and T at depths 0-0.20, 0.40-0.60, and 0.60-0.80 m; it also showed the need for different regression curves per layer, besides justifying the need for neutron probe calibration for each specific local condition.Item Chemical and hydrophysical attributes of an Oxisol under coffee intercropped with brachiaria in the Cerrado(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2016-09) Rocha, Omar Cruz; Ramos, Maria Lucrécia Gerosa; Veiga, Adriano Delly; Guerra, Antonio Fernando; Bartholo, Gabriel Ferreira; Rodrigues, Gustavo Costa; Silva, Juliano Escobar daThe objective of this work was to evaluate the effect of irrigation and of the presence of brachiaria (Urochloa decumbens) between coffee (Coffea arabica) rows on coffee yield and on chemical and hydrophysical attributes of a Typic Haplustox. The study was conducted in the Cerrado region in Planaltina, Brasília, DF, Brazil, in a randomized complete block design, arranged in split-split plots, with four replicates. Water regimes (irrigated or rainfed) were assigned to the main plots, inter-row management systems to the subplots, and soil layers to the sub-subplots. The following soil attributes were determined: total organic carbon, total nitrogen, C/N ratio, carbon and nitrogen stocks, bulk density, aggregate stability, total porosity, macroporosity, low-retention microporosity, remaining microporosity, criptoporosity, and total and readily-available water, besides coffee yield. Irrigation of coffee plants, associated with brachiaria intercropped as a cover crop, increased coffee yield and favored chemical and hydrophysical soil attributes, improving soil structure and its ability to store water. Irrigation favors organic carbon stocks in the upper soil layers, whereas brachiaria favors soil physical attributes related to water availability to coffee.Item Agronomic performance and adaptability of arabic coffee resistant to leaf rust in the central brasilian savanna(Editora UFLA, 2018-01) Veiga, Adriano Delly; Rocha, Omar Cruz; Guerra, Antônio Fernando; Bartholo, Gabriel Ferreira; Rodrigues, Gustavo Costa; Pereira, Welington; Silva, Thiago Paulo da; Silva, Evandro Ribeiro daBreeding programs and later indication of rust resistant cultivars for different environments and crops systems, in the concept of diseases integrated control, reach out for productivity raising and reduced production costs. The aim of this work was to evaluate the agronomic performance and adaptability of new Coffea arabica cultivars and progenies resistant to leaf rust in Central Brazilian Savanna. The experiment has been conducted since 2008 in an experimental area of Embrapa Hortaliças. Twenty three resistant cultivars, four progenies and three susceptible cultivars as controls, were assessed in a complete randomized block design with four replicates. The following traits were analyzed: plant height, stem diameter, canopy projection, number of plagiotropic branches, yield, grains percentage retained in sieves above 17, grain ripening and diseases resistance. Catucaí 2SL, Sacramento and Araponga stood out in vegetative growth. The highest yields are observed for IPR 103, Obatã 1669-20, Palma II, Sabiá 398 and Acauã, with values higher than 60 sacks per hectare. Among all these cultivars is observed high resistance to rust leaf and greater susceptibility to brown eye spot in the cultivar Acauã, for the place and period of evaluation.