Leonardo Santos Collier

Yield and quality of elephant grass biomass produced in the cerrados region for bioenergy

The objective of this study was to evaluate the performance of two genotypes of elephant grass, fertilized with and without N, for biomass production for energy use under the edaphoclimatic conditions of the Cerrado. The genotypes Roxo and Paraiso, grown in a field experiment in a Latosol in the Cerrado region were evaluated for biomass yield, nitrogen accumulation, C:N and stem:leaf ratios, fibre, ash and P and K contents and calorific value. The accumulated dry biomass ranged from 30 to 42 Mg ha-1 and showed no response to nitrogen fertilization with the lowest biomass obtained by the genotype Paraiso and the highest by Roxo. The total N accumulation followed the same pattern as for dry matter, ranging from 347 to 539 kg N ha-1. C:N and stem:leaf ratio of the biomass produced did not vary with treatments. The fibre contents were higher in genotype Paraiso and the highest levels of ash in the genotype Roxo. The K content in the biomass was higher in genotype Roxo and P did not vary between genotypes. The calorific value averaged 18 MJ kg-1 of dry matter and did not vary with the levels of N in leaves and stems of the plant. Both genotypes, independent of N fertilization, produced over 30 Mg ha-1 of biomass under Cerrado conditions.

Inoculação micorrízica no crescimento de mudas de angico em solo de cerrado

The objective of this research was to evaluate the Angico seedling growth [Anadenanthera macrocarpa (Benth.) Brenan] under the effect of arbuscular mycorrhizal fungi inoculation (FMAs) in preserved and antropized soils. This study was developed under greenhouse condition and the experiment was arranged in a complete random design within a factorial scheme 2x4 with five replications. There were two soils (preserved and antropized) and four treatments of mycorrhizal inoculation: (1) sterilized soil and inoculated with association of Glomus etunicatum + Paraglomus brasilianum; (2) sterilized soil and inoculated with association of Glomus etunicatum + Gigaspora margarita soil; (3) sterilized and not inoculated soil, i.e., control; and (4) natural soil (not sterilized and not inoculated). The growth in height was evaluated each 15 days and the leaf area, root and shoot dry matter, root length, shoot nutrient contents and mycorrhizal colonization were evaluated on the 150th day. The best growth of Angico seedlings was observed in the treatment with sterilized soil inoculated with a mixture of Gigaspora margarita and Glomus etunicatum, which caused increases in leaf area, root and shoot dry matter, as well as longer roots and larger mycorrhizal colonization, in both preserved and antropized soils.

Desenvolvimento, produtividade e qualidade dos frutos da videira em consórcio com culturas de cobertura

The use of permanent or partial vegetative cover of the soil in the vineyards can influence the production and the quality of the grape. Thus, the objective of this work was to evaluate the development of the grapevine productivity as well as the qualitative characteristics of ‘Isabel’ grape, in consortium with soil cover plants. The experiment was conducted in the municipality of Itapuranga, GO, and consisted of six treatments established in a randomized block design, in a 3 x 2 factorial scheme, in five replications. The first factor consisted of a plant species cover the soil: Jack Beans (Canavalia ensiformis L. DC), lab-lab (Dolichos lab lab L.) and spontaneous plants. In the second factor, there were two pruning seasons of the grapevine crop, based on the sowing of the cover crops. In other words, the first pruning season in the vine was performed 25 days after sowing (DAS) of the cover plants and the second pruning season in the vine was performed at 55 DAS. In three crop cycles, the soil cover plants consortium with the grapevine does not influence the morphological variables, the productivity, the variables associated with the productivity and the qualitative characteristics of the grape. Different times of pruning influence the productivity and the associated variables in the grape crop. The pruning at 25 days after sowing of the cover plants presented better results for the morphological variables and qualitative characteristics of the grape. Therefore, for the local conditions and for the evaluated time, use of hedge plants did not influence the production of the vines as well as the quality of the grape. However pruning times can affect the development of the vine, reflecting its productivity and quality.

ATRIBUTOS QUÍMICOS DO SOLO E PRODUTIVIDADE DE MILHO EM RESIDUAL DE LEGUMINOSAS EM SISTEMA AGROFLORESTAL

Leguminous species can improve nutrient cycling and chemical quality of Oxisols, resulting in higher productivity of intercropped crops. Thus, this research aimed to evaluate the decomposition rate and nutrient accumulation in legume stubble, as well as its contribution to soil chemical attributes, the growth of baru trees (Dipteryx alata Vogel), and yield of intercropped maize in an agroforestry system. The experiment was developed during the crop years of 2010-2011 and 2011-2012, in Goiás State, Brazil. The experimental design was a randomized block with five replicates. Leguminous species consisted of sunn hemp (Crotalaria juncea), jack bean (Canavalia ensiformis), pigeon pea (Cajanus cajan), Stylosanthes (Stylosanthes macrocephala 20% and Stylosanthes capitata 80%), and spontaneous vegetation (control treatment). The decomposition rates of legume and spontaneous vegetation residues remained unchanged in the agroforestry system. Sunn hemp, jack bean, and Stylosanthes plants are advantageous options for total accumulation of nutrients. However, sunn hemp grown as straw cover for next crop seasons increases the available phosphorus levels in the soil and productivity of maize cobs. With this coverage, maize productivity values were up to 24% higher than were those with maize growing on spontaneous vegetation, besides having no effect on the growth of baru trees.