Adriel Ferreira da Fonseca

Maize Growth and Changes in Soil Fertility After Irrigation with Treated Sewage Effluent. II. Soil Acidity, Exchangeable Cations, and Sulfur, Boron, and Heavy Metals Availability

Abstract The objective of this research was to study the effects of maize irrigation with secondary‐treated sewage effluent (STSE) on soil pH, electrical conductivity (EC), and on the available soil concentrations of calcium (Ca), magnesium (Mg), potassium (K), sodium (Na), aluminum (Al), sulfur (S), boron (B), and of heavy metals and to investigate the plant element accumulation, except for Al. The treatments consisted of mineral fertilization and irrigation with the STSE. After 58 days, maize plants were harvested, and soil and plant were analyzed. The STSE effectively reduced the mineral nitrogen fertilizer soil‐acidifying effect, induced increases in the EC, and in the base saturation, and did not significantly alter the available concentrations of S, B, and heavy metals. The STSE irrigation did not affect the shoot S, B, copper (Cu), iron (Fe), and manganese (Mn) contents in plants properly fertilized, but it induced a decrease in shoot zinc (Zn) content. Sodium was the most affected element by the STSE irrigation.

Maize and soybeans production in integrated system under no-tillage with different pasture combinations and animal categories

A adocao do sistema de plantio direto (SPD), aliado a integracao lavoura pecuaria (ILP) tem sido uma estrategia fomentada no Brasil, visando maximizar o rendimento das areas e aumentar a lucratividade do agronegocio. O objetivo deste trabalho foi avaliar o rendimento de graos e atributos fitotecnicos nas culturas de milho e soja, em sistema de ILP, sob plantio direto, apos o cultivo de pastos anuais de inverno, puros ou diversificados, com ausencia ou presenca de animais em pastejo de diferentes categorias. O experimento foi instalado no municipio de Castro (PR), em um Latossolo Bruno distrofico textura argilosa, empregando-se delineamento experimental de blocos completos aleatorizados, em esquema fatorial 4 x 2, com tres repeticoes. Os tratamentos incluiram quatro combinacoes de pastagens (diversificadas ou puras) e categorias de animais (leves e pesados), submetidas ou nao ao pastejo animal durante o inverno. Durante o verao de 2008/09 e 2009/10 a area foi cultivada com soja e milho, respectivamente, e procederam-se avaliacoes de rendimento de graos e atributos fitotecnicos. Os tratamentos nao alteraram o rendimento e o peso de mil sementes (PMS) de soja. Na cultura do milho, o pastejo animal, durante o inverno, aumentou a populacao de plantas e o rendimento de graos, mas proporcionou ligeira diminuicao no PMS. As combinacoes de pastos (diversificados ou puros) e categorias de animais (leves e pesados) nao interferiram na cultura da soja, mas beneficiaram a cultura do milho.

Cation exchange capacity of an oxisol amended with an effluent from domestic sewage treatment

The addition of Na-rich anthropogenic residues to tropical soils has stimulated the scientific community to study the role of sodium in both the soil solution and the exchange complex. In this study, several different methods were used to calculate the concentration of exchangeable and soluble cations and this data was then used to establish correlations between the level of these cations and both the accumulation of various elements and the dry weight of maize grown in a greenhouse under different conditions. In the closed environments of the pots, the most suitable method for calculating the effective cation exchange capacity (ECEC) was the cation exchange capacity calculated by cations removed with barium chloride solution (CECS). Then again, the actual cation exchange capacity (CECA) should be measured by using Mg adsorption to prevent ionic force from influencing electric charges. A strong positive correlation was obtained between the concentrations of Na in the 1:2 soil:water extracts and the accumulation of Na in the maize plants, indicating saline or double acid extractors are not needed when monitoring the Na concentration only.

Adsorção de metais pesados após calagem superficial em um Latossolo Vermelho sob sistema de plantio direto

There are few researches about control of soil acidy and adsorption of heavy metals in no-till system (NTS). The aim of this study was evaluate the cadmium (Cd), nickel (Ni), copper (Cu) and zinc (Zn) adsorption in a Rhodic Hapludox, clayey, without and with surface liming (4.5 t ha-1) under NTS. The experiment was established in Ponta Grossa, PR, in 1998. After 10 years, soil samples were collected to adsorption study. Doses of 0 to 180 mg L-1 of Cd and Ni, and of 0 to 180 mg L-1 of Cu and Zn were added, in competitive systems. After the equilibrium, the quantity of heavy metals was measured. Surface liming increased soil pH in all studied layers, resulting in improve of Cu, Zn, Cd and Ni adsorptions, mostly in the superficial layer. Moreover, surface liming changed dynamics of heavy metals in soil, being an efficient strategy to minimize environmental problems associate with Cd, Ni, Cu and Zn in NTS.

Nitrogen forms, pH and total carbon in a soil incubated with treated sewage effluent

In this study, an experiment under controlled conditions was carried out to determine the effects of secondary-treated sewage effluent (STSE) application on soil nitrogen concentrations (mineral and total), total carbon and soil pH. The soil and STSE used were collected at Lins, Sao Paulo State, Brazil. A completely randomized design was used, in completed factorial 4x11 (weekly application rates of 0, 100, 150 and 200 mL STSE per kg soil; and, eleven soil incubation periods from 0 to 10 weeks) with four replicates. The STSE was applied simulating common surface irrigation. Seven days after each incubation period, ammonium and nitrate contents were determined. Additionally, pH and total carbon and nitrogen contents were measured in the soil after 10 weeks. STSE application increased the nitrogen content (total and mineral - mainly as nitrate) and soil pH. For the total carbon content no differences were observed.

Soil physico-hydrical properties resulting from the management in Integrated Production Systems

Anthropic action, such as the soil use and management systems, promote changes in the soil structure. These changes might hamper the development of plants in soil management practices that involve its mobilization, and the negative effects might be increased due to intensive use. The aim of this study was to evaluate the physico-hydrical properties of a Haplohumox in integrated production systems under different soil managements. The soil superficial (0.0-0.10 m) and sub-superficial (0.10-0.20 m) layers were evaluated in the different systems: conventional tillage (CT), minimum tillage (MT), no-tillage (NT) and chiseled no-tillage (CNT), taking into consideration the annual ryegrass cropped for different uses [cover crop (C), grazing (G) and silage (S)] during the winter. Soil bulk density (Db), total porosity (TP), macro (Ma) and microporosity (Mi), water retention curves (SWRC) and water retention due to pore size (r) were determined. The annual ryegrass used as C produced lower Db and Mi and higher TP and Ma in CT, MT and CNT systems. No difference was verified between G and S in any of the management systems or soil layers. The superficial layer SWRC presented similar behavior regarding CT, MT and CNT. Under NT, C resulted in higher water retention. However, G and S provided higher water retention due to the pore size in this system.

Chemical and physical soil attributes in integrated crop-livestock system under no-tillage

Although integrated crop-livestock system (ICLS) under no-tillage (NT) is an attractive practice for intensify agricultural production, little regional information is available on the effects of animal grazing and trampling, particularly dairy heifers, on the soil chemical and physical attributes. The objective of this study was to evaluate the effects of animal grazing on the chemical and physical attributes of the soil after 21 months of ICLS under NT in a succession of annual winter pastures (2008), soybeans (2008/2009), annual winter pastures (2009), and maize (2009/10). The experiment was performed in the municipality of Castro (PR) in a dystrophic Humic Rhodic Hapludox with a clay texture. The treatments included a combination of two pasture (annual ryegrass monoculture and multicropping - annual ryegrass, black oat, white clover and red clover) with animal grazing during the fall-winter period with two animal weight categories (light and heavy), in a completely randomized block experimental design with 12 replications. After the maize harvest (21 months after beginning), soil samples were collected at 0-10 and 10-20 cm layers to measure soil chemical and physical attributes. The different combinations of pasture and animal weight did not alter the total organic carbon and nitrogen in the soil, but they influence the attributes of soil acidity and exchangeable cations. The monoculture pasture of ryegrass showed greater soil acidification process compared to the multicropping pasture. When using heavier animals, the multicropping pasture showed lesser increase in soil bulk density and greater macroporosity.

Viabilidade econômica da produção de novilhas leiteiras a pasto em sistema de integração lavoura-pecuária

O objetivo deste trabalho foi avaliar a rentabilidade do sistema de integracao lavoura-pecuaria (ILP), em comparacao ao cultivo de cereais de inverno e de plantas de cobertura para o plantio direto de soja e milho no verao. Foram comparados dados simulados de sistema agricola tradicional com producao de graos de milho e soja, no verao, e cultivo de trigo e plantas de cobertura do solo, no inverno; e dados de um trabalho publicado em que foram avaliadas combinacoes de pastagens (diversificadas ou puras) e categorias de animais (leves ou pesados), com producao de graos de milho e soja, no verao, e pastejo no inverno. A analise economica foi realizada com base nos resultados experimentais e simulada para uma propriedade de 100 ha. A ILP com recria de novilhas leiteiras em pastagens anuais de inverno, em substituicao ao sistema convencional com cultivo de cereais de inverno e plantas de cobertura de solo para o plantio direto, e a alternativa mais rentavel aos produtores.

Water Type and Irrigation Time Effects on Microbial Metabolism of a Soil Cultivated with Bermuda-grass Tifton 85

This study investigated the microbial metabolism in Bermuda-grass Tifton 85 areas after potable-water and effluent irrigation treatments. The experiment was carried out in Lins/SP with samples taken in the rainy and dry seasons (2006) after one year and three years of irrigation management, and set up on an entirely randomized block design with four treatments: C (control, without irrigation or fertilization), PW (potable water + 520 kg of N ha-1 year-1); TE3 and TE0 (treated effluent + 520 kg of N ha-1 year-1) for three years and one year, respectively. The parameters determined were: microbial biomass carbon, microbial activity, and metabolic quotient. Irrigation with wastewater after three years indicated no alteration in soil quality for C and ET3; for PW, a negative impact on soil quality (microbial biomass decrease) suggested that water-potable irrigation in Lins is not an adequate option. Microbial activity alterations observed in TE0 characterize a priming effect.

Soil structural quality degradation by the increase in grazing intensity in integrated crop-livestock system

ABSTRACT: The intensification of soil use, as in integrated crop-livestock system (ICLS), might promote soil structural degradation. A field method to evaluate the soil structural quality is the Visual Evaluation of Soil Structure (VESS). Studies on the application of this method to ICLS are few. This work aimed to evaluate the structural quality of a Dystrudept under ICLS and different grazing intensities through VESS. Thus, the soil structure was evaluated in light grazing (LG) and heavy grazing (HG) in comparison to a neighboring native forest (NF) as reference area. After the grazing period, 10 trenches were dug in each area to collect soil monoliths. The identification of structural differences and the attribution of visual scores were Soil And PlAnT nuTRiTion - Article Soil structural quality degradation by the increase in grazing intensity in integrated crop-livestock system Andre Carlos Auler 1 *, Shivelly Los Galetto, Fabricio Siqueira Hennipman 1 , Eduardo Daniel Guntzel 1 , Neyde Fabiola Giarola