Gilvan Moisés Bertollo

Doses de dejeto líquido de suínos na comunidade da fauna edáfica em sistema plantio direto e cultivo mínimo

The high production of liquid pig slurry makes the soil, the main alternative to its use as an organic fertilizer. However, the addition of organic residues in soil management systems is a factor that may influence the soil biota. The aim of this study was to evaluate the influence of dose application of liquid swine manure on soil biota in different cropping systems. The study was conducted in the experimental area located in the Taquarucu do Sul. The design was a randomized block factorial arrangement (2x5), two soil management (minimum and no tillage) and five doses (0, 20, 40, 80m3 ha-1 of liquid swine slurry and chemical fertilizer - ROLAS) with four replications. Sampling of soil biota was carried out with PROVID traps in plots of 22.5m2. It was evaluated the total group, springtails, mites, abundance, richness, Simpson’s index, Shannon’s diversity and Pielou’s index. The results indicate that no tillage system associated with 40 and 80m3 ha-1 resulted in a greater abundance of organisms, caused by the greater number of springtails. The mite population is larger in minimum tillage compared to no tillage at a rate of 80m3 ha-1. In no-tillage increases the dominance of Simpson and Shannon diversity decreases with increasing levels of liquid swine manure.

Population fluctuation in soil meso- and macrofauna by the successive application of pig slurry

Pig farming has increased in recent years, resulting in the production of a large quantity of liquid manure, which can be used as a source of organic fertiliser. The aim of this work was to determine the influence of pig slurry on the community of soil fauna in a system of direct seeding. The study was carried out in an experimental area in the town of Taquarucu do Sul, in the state of Rio Grande do Sul, Brazil. The experimental design was of randomised blocks in a (4 + 1) x 4 factorial scheme, comprising five fertilisation treatments, 0 (no fertiliser), 20, 40 and 80 m 3 of pig slurry ha -1 and one additional treatment (mineral fertiliser), with four evaluations corresponding to the number of slurry application (1st, 2nd, 3rd and 4th application), and four replications. The soil fauna was sampled using PROVID traps. The following were evaluated: the relative frequency of the groups of soil fauna, the populations of springtails and mites, density, richness, Simpsons dominance index and the Shannon diversity index. The populations of mites and springtails, and indices of diversity, richness and dominance are influenced by the successive application of pig slurry. Successive applications of pig slurry increase the diversity of the soil fauna by reducing the population of organisms of the Order Collembola. Canonical correlation analysis showed an association between the number of springtails and 80 m 3 of pig -1 after the third application.

Fauna edáfica influenciada pelo uso de culturas e consórcios de cobertura do solo

The edaphic fauna is considered sensitive and responds relatively fast to the impact of different types of production systems, thereby enabling its use as an active component for evaluating soil quality. This study was conducted to determine the influence of black oat, turnip, vetch and the intercropping of turnip/black oat and vetch/turnip/black oat in the structure and composition of the edaphic fauna. The experimental design was randomized blocks, in a 6x4 factorial scheme, consisting of six soil cover crops (black oat, turnip and vetch, the intercropping of turnip/black oat and vetch/turnip /black oat and fallow ground) and four sampling times (0, 50, 100 and 150 days after sowing), with four replications. After collecting the soil fauna, the abundance of individuals, Collembola number, Margalef richness, Shannon diversity index, Pielou equitability and Simpson dominance were determined. The intercropping of turnip/black oat and vetch/turnip/black oat favored the abundance of individuals and the Collembola number, within the first 50 days. The intercropping of vetch/turnip/black oat reduced the Shannon diversity index by increasing the Collembola population. The highest species diversity was observed at 100 days after the crops implantation. The edphic fauna was influenced by the vegetative stage and soil cover crop types.

CRESCIMENTO E TOLERÂNCIA DE MUDAS DE Enterolobium contortisiliquum Vell. CULTIVADAS EM SOLO CONTAMINADO COM ZINCO

Zinc is an essential element to plants, but when present in high concentrations in the soil can become toxic to the plant metabolism. The study aimed to determine the growth and tolerance of Enterolobium contortisiliquum Vell. seedlings cultived in soil contaminated with zinc. The experiment was conducted in a greenhouse in soil with 81% clay, in a completely randomized design with seven treatments, doses of zinc (0, 100, 200, 300, 400, 500 and 600 mg kg -1 ) eight repetitions. We evaluated the plant height, stem diameter, shoot dry mass, root dry mass, length of the main root, specific surface area, Zn content in shoots and roots, the impact coefficient of relative zinc content, translocation and tolerance. The ratio of the impact on the zinc content showed lower tendency to translocation of Zn from the air to the change of the dose of 300 mg kg -1 Zn soil. The results showed that close to 200 mg Zinc kg -1 clay soil doses stimulate plant height, stem diameter, stem and root dry mass of seedlings and timbauva. Timbauva presents high tolerance to zinc and because it is a native tree adapted to Brazilian environmental conditions it can be indicated for revegetation of contaminated areas with the application of up to 600 mg of zinc kg-1 of clay soil.

WINTER COVER CROPS INFLUENCE IN EDAPHIC FAUNA COMMUNITY STRUCTURE

The use of cover crops contributes to soil management by improvingtheir biological characteristics. The aim of this study was to determinethe contribution of winter cover crops in mesofauna and macrofaunacommunity. The work was developed at the experimental area of theFederal University of Santa Maria, on Frederico Wesphalen campus, inrandomized block design, in a factorial 6 x 4, being six winter covercrops (oats - Avena sativa L.; ryegrass - Lolium multiflorum L.; canola- Brassica napus L.; linseed - Linum usitatissimum L.; triticale - Triticosecale Witt. and fallow vegetated area) and four sampling times (0, 50,100 and 150 days after sowing), with four repetitions. Samples were collectedwith PROVID traps, staying in the field for seven days. The capturedindividuals from the traps were identified by class or order. It wasevaluated the quantity of individuals and the Margalef richness index,Simpson dominance, Shannon diversity and Pielou evenness. The multivariableanalysis of different sampling times was realized based onthe number of individuals. The results showed that winter cover cropscontribute to increasing amount of individuals of soil fauna. The usedcover crop used and its development stage induce the Shannon diversityindex and the Simpson dominance.