Mario M. Rolim

Uso de diferentes doses de manipueira na cultura da alface em substituição à adubação mineral

The main goal of this work was to evaluate the effect on agronomic characteristics of the lettuce when using different doses of cassava wastewater instead of mineral fertilizer. This study was conducted at the Departamento de Tecnologia Rural da Universidade Rural de Pernambuco, Recife, PE, from May to August 2010. The experiment was carried out under greenhouse conditions in a completely randomized blocks, with six treatments and five repetitions. Following doses were used: 0, 5, 15, 25, 45 and 65 m3 ha-1. The lettuce cultivar Regina 2000 was used (one plant per pot) and leaf area, plant height, number of leaves, fresh leaf mass and dry leaf mass were evaluated for each dose of cassava wastewater. At the end of the experiment, the dose of 45 m3 ha-1 provided the best results by increasing plant height, leaf area, fresh and dry material. Thus, the cassava wastewater can be successfully used as a source of fertilizer for a lettuce crop if the adequate dose is used.

Avaliação de solos sob diferentes períodos de aplicação com vinhaça

The objective of this study was to evaluate physico-chemical alterations associated to soil depth and respective correlations in soils under periods of different stillage fertigation. Therefore, four areas were selected at Usina Santa Tereza: Area 1), irrigated with stillage for 3 years; Area 2), for 7 years; Area 3), 10 years; Area 4), without stillage application. In each area 20 points were demarcated and georeferenced, forming a mesh. Soil samples were collected at depths of 0 - 10, 10 - 20 and 20 - 40 cm. After sampling, the soil was air dried, prepared and passed through sieves for analysis of particle size: sand, silt, clay, and for the physico-chemical properties: exchangeahle Ca, Mg, K, Na; pH (1:2.5 soil: water); and electrical conductivity of saturated paste extract. Simple linear correlation coefficients of Pearson between pairs of data were obtained. The results pointed out relation between depth and other variables in all areas, indicating stillage application alters cation concentration depending on soil characteristics and management of each area.

Correção de solos salino-sódicos pela aplicação de gesso mineral

With the objective of quantifying the parameters that determine the effectiveness of gypsum in the reclamation of saline-sodic soils in the Irrigated Perimeter of Custodia located in the State of Pernambuco, Brazil, with the purpose of increasing the available areas for irrigated agriculture, an experiment was carried out in soil columns installed at the Soil Mechanics and Residue Recovery Laboratory at the Universidade Federal Rural de Pernambuco. The treatments were arranged in a randomized blocks and a factorial scheme of two soils and six levels of mined gypsum equivalent to 25, 50, 75, 100, 125 and 150% of gypsum requirements of the soil determined by Schoonover M-1 laboratory method, incorporated to the first 5 cm of the soil column, with three replications. The evaluated components were the electrical conductivity, the sodium adsorption ratio (SAR) and the soluble cations of the saturation extract. The level of gypsum equivalent to 100% of the gypsum requirement showed to be most effective at reducing the SAR of the extract, reducing soil contents of sodium in the soil.

Compressibilidade de um Argissolo Amarelo distrocoeso submetido a diferentes manejos

The objective of this paper was to evaluate the compressibility of an Ultisol submitted to different managements of sugarcane cultivation. The investigation was carried out at Triunfo Mill, in the State of Alagoas, Brazil. The testing area was composed by four distinct sub-areas: a preserved forest (NF), an area without irrigation (MWOI), an irrigated area (MWI), and an area with vinasse (MWV). All investigated areas, except the forest, were prepared using conventional equipment for soil preparation. Soil samples were collected within depths ranging from 0 to 20 cm, 20 to 40 cm, and 40 to 60 cm. A trench was dug in the four selected areas and four undeformed samples were collected in each depth. The samples were collected with metallic rings with dimensions of 6.4 cm in diameter and 2.5 cm in height. In the laboratory, the samples were previously saturated and submitted to soil suctions raging from 0.1 to 1500 kPa in order to build the soil-water characteristic curves. Confined compression tests were performed with saturated samples. The results obtained from the compression tests were used for the determination of the void ratio (e) and the pre-consolidation stress (σp) of the tested samples. Data were submitted to regression analysis and the differences among the obtained means were compared using the test of Tukey at 5% of probability. Regression analysis for pre-consolidation stress in function of water content (Ug) and correlations among the several variables were carried out at 5-% significance. Within all investigated areas, the depth range from 0 to 20 cm showed to be more susceptible to compaction in relation to the depth range from 20 to 40 cm. Management MWV was found to modify the compressive behavior of the soil in both depth ranges. In all investigated areas, the soil bearing capacity was higher in the depth range of 20 to 40 cm.

Compaction of a Ultisol submitted to different managements.

The objective of this work was to evaluate the susceptibility to compaction of an utisoil under different soil managements and use. Evaluations were based on both maximum density (MD) and critical humidity (CH) through Standard Proctor compaction tests, and the degree of compaction in different soil managements and use. The study was carried out at the Triunfo Mill, State of Alagoas in Brazil. The testing area consisted of four distinct sub-areas: a preserved forest (MA), an area without irrigation (MSI), an irrigated area (MCI), and an area with vinasse (MCV). Undeformed soil samples were collected for soil density and the deformed ones for organic matter and Standard Proctor tests in order to obtain MD, CH and the compaction grade (CG). Plots (50 × 50 m) were randomized within the four areas at depths of 0-20, 20-40 and 40-60 cm, with three replications. Data were submitted to variance analyses, and means compared through the Tukey test at 5% of probability. MD data followed the grade MSI > MCI > MCV > MA, in contrast to CH which presented the inverse sequence. Therefore MSI and MCI can cause soil degradation, even at lower CH. Only MCI presented CG higher than 4.3%, the critical value reference, at 0-20 cm.

Desenvolvimento e acúmulo de macronutrientes em plantas de milho biofertilizadas com manipueira

Objetivou-se, neste estudo, avaliar o desenvolvimento vegetativo e o acumulo de macronutrientes em plantas de milho submetidas as doses de manipueira. O experimento foi conduzido em ambiente protegido no periodo de marco a maio de 2011. O delineamento experimental foi inteiramente casualizado em esquema fatorial 2 (tipos de solo: franco-arenoso e franco-argiloso) × 4 (doses de manipueira: 0; 11,2; 22,4 e 44,8 m3 ha-1), com oito repeticoes. As variaveis analisadas foram: altura das plantas, diâmetro de colmos, numero de folhas, materia fresca e materia seca da parte aerea das plantas e teores de N, P, K, Ca e Mg no tecido foliar. O aumento das doses de manipueira elevou o conteudo de massa fresca, o teor de nitrogenio e potassio da parte aerea das plantas, mas diminuiu a altura das plantas e o teor de magnesio na parte aerea das plantas. Os acrescimos de materia seca e de calcio na parte aerea das plantas foram maiores no solo franco-arenoso.

Qualidade do percolado de solos que receberam vinhaça em diferentes doses e tempo de incubação

The objective of this study was to evaluate the quality of percolation from three soil classes that received vinasse doses with different incubation times. The soils, classified as Haplic Nitosol, Yellow Argisol and Carbic Spodosol, were reproduced in twenty-seven 20 × 110 cm PVC columns (diameter × height) with horizons, thickness and densities similar to original soil. The soils were treated with vinasse doses equivalent to 0 (control), 350 and 700 m3 ha-1, and submitted to 30 and 60 days incubation. The collected effluents were analyzed for BOD5, COD, EC, TDS and pH. The results indicated that variations in the analyzed parameters, due to vinasse application in the soil, do not bring concerns in relation to environmental quality. Despite different textures and consequently, different physiochemical properties, the comparison of percolates with natural vinasse data indicated that the soils presented high retention power, reducing the possibility of this waste causing pollution to the subsurface waters.

Alterações dos atributos físicos e químicos de um Neossolo após aplicação de doses de manipueira

The effluent from cassava industrial processing presents high ionic organic charge and high nutrient concentration. If discarded indiscriminately in soil, this effluent may cause serious environmental hazard. The objective of this paper is to evaluate changes in physical and chemical attributes of a soil cultivated with lettuce and submitted to increasing doses of cassava wastewater. The experiment was carried out under greenhouse in a completely randomized design with six treatments consisting of application of 0, 5, 15, 25, 45 and 65 m3 ha-1 and five replications. Soil physical (degree of flocculation, dispersed clay in water) and chemical (electrical conductivity of saturation extract of soil, pH, content of P and exchangeable cations K+, Ca2+, Mg2+ and Na+) properties were evaluated for soil characterization. Besides decreasing clay dispersed in water, use of cassava wastewater in the soil increased flocculation degree, pH, electrical conductivity of saturation extract, exchangeable cations and P content. Tendency of soil salinization was observed after cassava wastewater application.

Distribution of aggregates and organic carbon in an Ultisol submitted to different managements

The main objective of this study was to evaluate the stability and aggregate distribution of an Ultisol submitted to different management systems under sugarcane cultivation. Evaluated areas consisted of native forest (MA) and sugarcane managed areas with irrigation (MCI), vinasse irrigation (MCV) and without irrigation (MSI). Management of the areas followed the same conventional preparation: heavy and light harrowing and subsoiling. Undeformed soil samples were collected along the lines of the crop and in native forest to determine aggregate stability, expressed by the average weighted diameter (DMP), aggregate stability index (IEA), module of thinness (MF), percentage of stable aggregate in water larger than 2.0 mm (AGRI) and total organic carbon. The distinct kinds of soil management on sugarcane promoted decrease in aggregate stability as soil depth increased. In relation to native forest, aggregate stability reduced in the sequence MA > MCV > MCI > MSI. MSI showed the lowest aggregation indexes, in contrast to MCV data which closely linked with MA data and presented the best aggregate stability index in water. Significant and positive correlations were obtained between total organic carbon and stability indexes studied (DMP > AGRI > MF > IEA) under different management situations.

Development and mineral composition of corn as a function of soil compaction and application of organic compost

The objective of the this study was to evaluate the effect of organic compost and compaction levels of two soils on shoot dry weight and macronutrient contents of corn (Zea mays), cultivar Itapoa 700. In 54 pots, three doses of the processed organic compost residue from Recife Central Market were applied in two soils, one being a dark red Argissoil (DRA) and the other a yellow red Argissoil (YRA), collected in Ap horizon (0 to 0.20 m depth) and under three compaction levels in a factorial arrangement 2 × 3 × 3 with three replications. Shoot dry matter and N, P, K, Ca and Mg contents were evaluated. The results indicate that soil compaction does not affect corn growth. The organic compost application increased K and Ca but decreased Mg content in shoots. Calcium content in corn shoot increased with the organic compost in DRA soil, but was found to decrease in YRA soil.