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4 results on '"Moraes, Moacir Tuzzin de"'

1. Soil load support capacity increases with time without soil mobilization as a result of age-hardening phenomenon.

Author

Moraes, Moacir Tuzzin de, Luz, Felipe Bonini da, Debiasi, Henrique, Franchini, Julio Cezar, and Silva, Vanderlei Rodrigues da

Subjects
*SOILS, *SOIL compaction, *OXISOLS, *TILLAGE, *DENSITY
Abstract

Highlights • Age-hardening phenomena were analysed by soil load support capacity in no-tillage. • For the same bulk density and water content, soil strength was higher over time without soil mobilization. • No-tillage over time increases the soil load support capacity due particle bond strengthening. Abstract Soil compaction is a result of soil compression, and this effect depends on the pressure applied and the soil structure. Nevertheless, studies regarding the effects of long-term tillage systems on strengthening of particle bonds are scarce. Thus, we aimed to study the soil bond strengthening due to the age-hardening phenomenon using the soil load support capacity model of an Oxisol managed under different tillage systems in Southern Brazil. Soil samples were collected from three soil layers (0.0–0.10 m; 0.10–0.20 m and 0.20–0.30 m) and five soil tillage systems of conventional tillage; minimum tillage with chiselling performed every year or every three years; and no-tillage for 11 or 24 years. Age-hardening was investigated using the soil load support capacity model. Soil cores were equilibrated at four matric potentials (−6, −33, −100 and −500 kPa) and submitted to uniaxial compression tests to obtain preconsolidation pressure. The soil load support capacity models were affected by the tillage systems. The long-term no-tillage presented the highest soil load support capacity for the same bulk density and water content in all layers, demonstrating greater resistance to additional compaction. Higher preconsolidation pressure values in long-term no-tillage at the same soil bulk density and water content were attributed to the age-hardening phenomena, which increased the number and strength of bonds among soil particles, leading to higher soil cohesion. Longer time under no-tillage improves the soil structure and soil load support capacity. Thus, soil mobilization strongly affected the soil structure by breaking particle bonds leading to the greater compaction. [ABSTRACT FROM AUTHOR]

Published
2019
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2. Changes in a Rhodic Hapludox under no-tillage and urban waste compost in the northwest of Rio Grande do Sul, Brazil

Author

Moraes, Moacir Tuzzin de, Silva, Vanderlei Rodrigues da, Cherubin, Maurício Roberto, Carlesso, Reimar, Debiasi, Henrique, and Levien, Renato

Subjects
soil organic carbon, organic manure, total nitrogen, estabilidade de agregados, resíduo orgânico, soil structure, carbono orgânico, aggregate stability, estrutura do solo
Abstract

The use of urban waste compost as nutrient source in agriculture has been a subject of investigation in Brazil and elsewhere, although the effects on soil physical and chemical properties and processes are still poorly known. The aim of this study was to evaluate the effect of application of urban waste compost and mineral fertilizer on soil aggregate stability and organic carbon and total nitrogen content of a Rhodic Hapludox under no-tillage in the northwestern region of Rio Grande do Sul, Brazil, in the 2009/2010 and 2010/2011 growing seasons. The experiment was arranged in a 2 × 6 (seasons and fertilization) factorial in a randomized complete block design with four replications. The factor time consisted of two growing seasons (sunflower in 2009/10 and maize in 2010/11) and the factor fertilization of five rates of urban waste compost (0, 25, 50, 75 and 100 m³ ha-1), and mineral fertilizer. Soil samples were collected from the 0.0-0.10 m layer to determine aggregate stability (mean weight and geometric diameter), soil organic carbon (SOC) and total nitrogen (TN). Rates of up to 75 m³ ha-1 of urban waste compost, after two years of application to no-tillage maize and sunflower, improved aggregation compared to mineral fertilization in a Rhodic Hapludox. After the second crop, the SOC and TN contents increased linearly with the levels of urban waste compost. A utilização de composto de lixo urbano como fonte de nutrientes para a agricultura vem sendo investigada; entretanto, as alterações físicas do solo ainda são pouco conhecidas. Objetivou-se avaliar a influência do uso de composto de lixo urbano e da adubação mineral na estabilidade de agregados e nos teores de carbono orgânico e nitrogênio total de um Latossolo Vermelho, em sistema plantio direto na região noroeste do Rio Grande do Sul. Utilizou-se o delineamento de blocos ao acaso, em esquema fatorial 6 × 2 (adubação e épocas), com quatro repetições. O fator épocas de avaliação constituiu-se dos anos agrícolas de 2009/10 (girassol) e 2010/11 (milho). O fator adubação foi composto por cinco doses de composto de lixo urbano (0, 25, 50, 75 e 100 m³ ha-1), além de um tratamento adicional com fertilização mineral. Na camada de 0,0-0,10 m, foram determinados a estabilidade de agregados (diâmetro médio geométrico e ponderado), os teores de carbono orgânico (CO) e o nitrogênio total (NT). A utilização de doses crescentes de composto de lixo urbano favoreceu melhorias na agregação do solo, em relação à fertilização mineral. A utilização de até 75 m³ ha-1 de composto de lixo urbano, após dois anos de aplicações em cultivos agrícolas com milho e girassol em um Latossolo Vermelho, sob sistema plantio direto, promoveu melhorias na agregação do solo, quando comparada à fertilização mineral. O teor de CO e o de NT, após o segundo cultivo, apresentaram incrementos lineares, em relação às doses de composto de lixo urbano.

Published
2014

3. Microbial attributes as structural quality index for physical health of an Oxisol under compaction levels.

Author

Tonon-Debiasi, Brenda Cristye, Debiasi, Henrique, Rondina, Artur Berbel Lirio, Moraes, Moacir Tuzzin de, Franchini, Julio Cezar, Balbinot Junior, Alvadi Antônio, Hungria, Mariangela, and Nogueira, Marco Antonio

Subjects
*COVER crops, *SOIL structure, *NO-tillage, *SOIL compaction, *COMPACTING, *SOIL management, *SOIL degradation
Abstract

Microbial activity is a sensitive indicator of soil structure improvement provided by plant species in the physical recovery of compacted soils. This study aimed to assess the impacts of crop species on soil aggregate classes for soil recovery after compaction and identify which microbial attributes best describe the structural quality index for soil physical health in an Oxisol under no-tillage. The experiment comprised three crop species—maize, ruzigrass, and black oats—cultivated under four degrees of compactness produced by chiseling or machine traffic under long-term no-tillage. Soil aggregates were separated by dry sieving into five diameter classes to assess the basal respiration, microbial biomass carbon, metabolic quotient for CO 2 (q CO 2), labile carbon, cellulase activity, and total organic carbon. The values of microbial indicators for the bulk soil were estimated as a weighted mean of each attribute using aggregate size distribution. The lowest values for total organic carbon, labile carbon, and microbial biomass carbon were observed in aggregates > 4 mm. The basal respiration values increased from 8.2 µg C-CO 2 g d−1 in the aggregates > 4 mm, to 22.1 µg C-CO 2 g soil d−1 in the aggregates < 0.5 mm (+170%). Similarly, the cellulase activity increased approximately four times comparing aggregates > 4 mm (38 µg glucose g−1 d−1) to those < 1 mm (181 µg glucose g−1 d−1). The total organic carbon and microbial biomass carbon were found to be little affected by crops. However, the plots cultivated with black oats or ruzigrass exhibited higher cellulase activity, basal respiration, and q CO 2 in comparison with maize, primarily due to the greater content of labile carbon. Increasing the mean weight diameter from 3 mm to 8 mm led to a decrease in the labile carbon (−27.4%), microbial biomass carbon (−25.5%), cellulase activity (−70%), and basal respiration (−21.6%), thereby revealing negative effects of soil compaction on microbial attributes. The degree of compactness did not influence the values of total organic carbon and q CO 2. The response of the microbial indicators depends on the aggregate diameter classes. The results of this study indicate that cultivation of cover crops decreases the negative impacts of soil structure degradation on soil microbial quality. Cellulase activity and labile carbon were considered as new potential indicators of soil compaction for soil physical health studies—highly sensitive and quickly responsive to managements that induce soil structure changes in an Oxisol. • We tested the microbial attributes as a soil structural indicator. • Soil management affect biological indicators of soil physical health. • Soil aggregate quality were evaluated by microbial attributes. • Cellulase activity and labile carbon in aggregates may use as a soil physical health assessment. • Soil compaction is identified by the microbial attributes inside the soil aggregates. [ABSTRACT FROM AUTHOR]

Published
2024
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4. Extraction strategies and sample thickness for visualevaluation of soil structure

Author

Pacheco, Vacilania, Guimarães, Rachel Muylaert Locks, Tormena, Cássio Antonio, and Moraes, Moacir Tuzzin de

Subjects
Latossolos, Soil structure, Soils - Sampling, Agronomia, CIENCIAS AGRARIAS::AGRONOMIA [CNPQ], Solos - Amostragem, Soils - Quality, Estrutura do solo, Ferralsols, Solos - Qualidade
Abstract

Conselho Nacional do Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) O objetivo deste trabalho foi a) avaliar se diferentes espessuras das amostras resultam em mudanças no índice de qualidade estrutural (Sq) do solo pelo método VESS b) testar diferentes ferramentas de extração de amostra para proceder a avaliação da Sq-VESS e c) avaliar diferentes estratégias de exposição dos agregados do solo durante a avaliação do VESS; em Latossolos argilosos basálticos. As avaliações da espessura das amostras foram feitas em áreas sob plantio direto em Guarapuava, Pato Branco e São Jorge do Ivaí. Em cada área foram retiradas dez amostras de 15 x 25 cm (largura e profundidade), com uma pá reta, nas espessuras: 5; 10; 15; 20 e 25 cm. As avaliações das ferramentas de extração foram realizadas em três áreas em Pato Branco, tomando dez amostras para cada uma das ferramentas: pá de corte; pá + marreta + madeira; pá de impacto; pá jardineira; forcado; motosserra e pá acoplada a um trator. Nos mesmos locais da avaliação das ferramentas, foram avaliadas três estratégias de desagregação: manual; golpear a pá com uma marreta; e golpear a pá no chão, totalizando 30 amostras. Foram avaliados o escore Sq e aspectos práticos na extração das amostras. As amostras com espessura de 5 cm apresentaram menor Sq devido a redução dos agregados pelo corte pela pá. Para amostras com espessura de 20 cm verificou-se maior dificuldade de extração. A extração de amostras de 10 cm apresentou maior praticidade quando comparada às de 15 cm (método padrão), pelo menor volume de solo extraído. Não foi possível avaliar o escore Sq nas amostras de espessura de 25 cm pela grande dificuldade de extração da amostra. A integridade das amostras é preservada com o uso de pá de impacto e da motosserra, enquanto que a pá acoplada ao trator produziu grande compactação nas laterais e na porção inferior da amostra. A utilização de pá+marreta+madeira causou desestruturação na porção superior da amostra. As ferramentas pá jardineira e forçado não possibilitaram a extração da amostra. Desagregar o solo realizando batidas na pá com a marreta ou no chão promoveu dispersão do solo e mistura das camadas. Os resultados sugerem que a extração de amostras com espessura de 10 cm também pode ser utilizada para obter o escore Sq. O melhor método para extração da amostra é com a pá de corte, a pá de impacto e a motosserra e; a técnica recomendada para a desagregação é a manual. The objective of this work was a) to evaluate whether different thicknesses of the samples result in changes in the structural quality index (Sq) of the soil by the VESS method b) to test different sample extraction tools to proceed with the evaluation of the Sq-VESS and c) to evaluate different exposure strategies of soil aggregates during VESS assessment; in basaltic clayey Oxisols. The thickness evaluations of the samples were made in areas under no-tillage in Guarapuava, Pato Branco and São Jorge do Ivaí. Ten samples of 15 x 25 cm (width and depth) were taken in each area, with a straight shovel, in thicknesses: 5; 10; 15; 20 and 25 cm. The assessments of the extraction tools were carried out in three areas in Pato Branco, taking ten samples for each of the tools: cutting shovel; shovel + mallet + wood; impact shovel; garden shovel; pitchfork; chainsaw and shovel attached to a tractor. In the same places where the tools were evaluated, three disaggregation strategies were evaluated: manual; striking the shovel with a sledgehammer; and to hit the shovel on the floor, totaling 30 samples. The Sq score and practical aspects of sample extraction were evaluated. Samples with a thickness of 5 cm showed lower Sq due to the reduction of aggregates by cutting through the shovel. For samples with a thickness of 20 cm, there was greater difficulty in extraction. Extracting 10 cm samples was more practical when compared to 15 cm samples (standard method), due to the smaller volume of soil extracted. It was not possible to evaluate the Sq score in 25 cm thick samples due to the great difficulty in extracting the sample. The integrity of the samples is preserved with the use of an impact shovel and chainsaw, while the blade coupled to the tractor produced great compaction on the sides and the lower portion of the sample. The use of shovel + mallet + wood caused disruption in the upper portion of the sample. The garden shovel and pitchfork tools did not allow sample extraction. Disaggregating the soil by tapping the shovel with the mallet or on the ground promoted soil dispersion and mixing of the layers. The results suggest that the extraction of samples with a thickness of 10 cm can also be used to obtain the Sq score. The best method for extracting the sample is with the cutting shovel, the impact shovel and the chainsaw and; the recommended technique for isaggregation is manual.

Published
2020

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