Doses de gesso em cafeeiro: influência nos teores de cálcio, magnésio, potássio e ph na solução de um latossolo vermelho distrófico

Oliveira

Carducci

et al. 2016

SCA

Self Cite

Morphological characteristics of the soil aggregates are important tools to analyzing and monitoring the structural quality. The present study aimed to characterize morphometrically aggregates of a Inceptisol, originated from pelitic rocks, after 1.5 years of the implementation of a management system that adopts conservation tillage practices in the coffee cultivation. The aggregates were collected at the depths of 0.0-0.05; 0. 05-0.20; 0.20-0.40; 0.40-0.80 m, both at row and interrow position in a coffee field, and also a natural environment of native vegetation that was used as a reference for the study. The analyzes of the aggregates were carried through 2D images obtained by scanning at 300 dpi spatial resolution. Each image contained 60 households and were processed using the software QUANTPORO. The morphometric variables were obtained: area, perimeter, compactness, roughness, appearance and Ferret diameter. For validation, the correlations among morphometric variables determined by image analysis and pattern aggregation indices (GMD, MWD and aggregates retained in the class > 2.00 mm) obtained by wet sieving were studied. After 1.5 years of implantation increased the dimensions of the aggregates on the natural environment have been detected, as well as better structural quality Inceptisol. Key words: Image analysis. Morphometric characteristics of the aggregates. Structural quality. ResumoAs características morfológicas dos agregados são importantes indicadores da qualidade estrutural do solo. O presente trabalho teve por objetivo caracterizar morfometricamente os agregados de um Cambissolo originado de rochas pelíticas (siltito) após 1,5 anos da implantação de um sistema de manejo que adota práticas conservacionistas do solo no cultivo do cafeeiro. Os agregados foram coletados nas profundidades de 0,0-0,05; 0,05-0,20; 0,20-0,40; 0,40-0,80 m, nas posições linha e entrelinha do cafeeiro e também em um ambiente natural Cerrado Nativo tomado como referência para o estudo. As análises dos agregados foram realizadas por meio de imagens 2D obtidas por escaneamento, em 300 dpi de resolução espacial. Cada imagem continha 60 agregados e foram processadas utilizando o software Quantporo. As variáveis morfométricas obtidas foram: área, perímetro, compacidade, rugosidade, aspecto e diâmetro de Ferret. Para validação, foram estudadas as correlações entre as variáveis 1 Parte da Dissertação do primeiro autor. Trabalho financiado pelos órgãos CNPq e FAPEMIG.

Section: Resultsmentioning

confidence: 99%

Aggregates morphometry of a Inceptisol under conservationist system

Oliveira

Carducci

et al. 2016

SCA

Self Cite

“…In G-0, although no additional gypsum was applied to supply Ca for plant nutrition, calcium nitrate (105 kg ha -1 ) was used to maintain adequate to high soil Ca 2+ levels (Ramos et al, 2013), explaining the very stable aggregates observed in this treatment.…”

Section: Resultsmentioning

confidence: 99%

“…Therefore, at a depth of 0.20 m, there was a reservoir of gypsum, which, due to dry conditions in the Upper São Francisco region, underwent slow dissolution and gradually released Ca 2+ to the soil at appropriate levels (27 mmol c dm -3 ). This initiated the clay flocculation process, and promoted soil aggregation improvements (Cremon et al, 2009;Ramos et al, 2013;Silva et al, 2013).…”

Section: Resultsmentioning

confidence: 99%

Aggregate stability by the "high energy moisture characteristic" method in an oxisol under differentiated management

Oliveira

et al. 2014

Rev. Bras. Ciênc. Solo

Self Cite

SUMMARYStudies testing the High Energy Moisture Characteristic (HEMC) technique in tropical soils are still incipient. By this method, the effects of different management systems can be evaluated. This study investigated the aggregation state of an Oxisol under coffee with Brachiaria between crop rows and surfaceapplied gypsum rates using HEMC. Soil in an experimental area in the Upper São Francisco region, Minas Gerais, was studied at depths of 0.05 and 0.20 m in coffee rows. The treatments consisted of 0, 7, and 28 Mg ha -1 of agricultural gypsum rates distributed on the soil surface of the coffee rows, between which Brachiaria was grown and periodically cut, and compared with a treatment without Brachiaria between coffee rows and no gypsum application. To determine the aggregation state using the HEMC method, soil aggregates were placed in a Büchner funnel (500 mL) and wetted using a peristaltic pump with a volumetric syringe. The wetting was applied increasingly at two pre-set speeds: slow (2 mm h -1 ) and fast (100 mm h -1 ). Once saturated, the aggregates were exposed to a gradually increasing tension by the displacement of a water column (varying from 0 to 30 cm) to obtain the moisture retention curve [M = f (Ψ Ψ Ψ Ψ Ψ)], underlying the calculation of the stability parameters: modal suction, volume of drainable pores (VDP), stability index (slow and fast), VDP ratio, and stability ratio. The HEMC method conferred sensitivity in quantifying the aggregate stability parameters, and independent of whether gypsum was used, the soil managed with Brachiaria between the coffee rows,

“…After 2.5 years was 27 and50 mmol c dm -3 in G0 and G7, respectively, and in G28 was 48 mmol c dm -3 (Silva et al 2013;Ramos et al 2013). In G7 quantities are insufficient to act as an aggregate dispersing agent (Spera et al 2008;Cremon et al 2009).…”

Section: Treatmentsmentioning

confidence: 97%

Spatial variability of pores in oxidic latosol under a conservation management system with different gypsium doses

et al. 2014

Soil structure is modify when subjected to the agricultural process, i.e., a new spatial organization of the pores system is formed, with relation to the physical quality of it. Thus the aim of this work was to visualize and quantify, through X-ray CT scan, the pores distribution in an oxidic Latosol submitted to a conservation management system with different gypsum doses. Three random trenches were dug lengthwise along the plant row in a very clayey gibbsitic dystrophic Red Latosol, subjected to the following gypsum levels: G0: absence of gypsum; G7: 7 Mg ha-1 and G28: 28 Mg ha-1 of additional gypsum, applied to the surface of the plant row. Undisturbed soil samples were collected in plexiglass tubes at depths of 0.20-0.34, 0.80-0.94 and 1.50-1.64 m after six years of coffee cultivation for quantification of 3D pores obtained by X-ray CT scan. The spatial variability of the soil structure was evaluated by semivariograms generated by 3D images in grayscale. Distribution of the detectable pore diameter was conducted by data mining. Statistical analyzes employed packages 'geoR' to semivariogram and 'randomForest' for data mining in R language. A greater spatial continuity of the pores occurred in the G7 at the three depths. The combined effects of the management system promoted a greater spatial variability of the soil structure in the G28 treatment. Based on geostatistical analyses, it can be infer that the adoption of the system under study promoted changes in the pore network in all directions (X, Y and Z), however with better pores continuity in the vertical direction(Z).Index terms: X-ray CT scan, spatial pore continuity, pores distribution, coffee crop. RESUMOA estrutura do solo é alterada quando submetida ao processo agrícola, ou seja, uma nova organização espacial do sistema poroso é formada com reflexo na qualidade física do mesmo. Dessa forma, objetivou-se, neste trabalho, visualizar e quantificar, por meio da tomografia computada de raios-X, a variabilidade na distribuição do diâmetro de poros em Latossolo oxidíco submetido a um sistema de manejo conservacionista que utiliza diferentes doses de gesso. Foram abertas três trincheiras aleatórias e longitudinais à linha de plantio em um Latossolo Vermelho distrófico gibbsítico muito argiloso, submetido às seguintes doses de gesso: G0: ausência de gesso; G7: 7 Mg ha -1 e G28: 28 Mg ha -1 de gesso adicional, aplicados na superfície do solo na linha de plantio. Amostras com estrutura preservada foram coletadas em cilindros de acrílico, nas profundidades de 0,20-0,34, 0,80-0,94 e 1,50-1,64 m, após seis anos de cultivo dos cafeeiros ,para quantificação dos poros 3D, detectados pela tomografia computada de raios-X. A variabilidade espacial da estrutura do solo foi avaliada por meio de semivariogramas gerados a partir das imagens 3D na escala de cinza. A distribuição do diâmetro dos poros detectáveis foi feita por meio da mineração de dados. Paras as inferências estatísticas, foram utilizados os pacotes 'geoR' para os semivariogramas e 'randomForest' para...