Luiz Fernando Spinelli Pinto

Fontes de potássio em solos distroférricos cauliníticos originados de basalto no Rio Grande do Sul

The objective of this study was to identify the K-bearing minerals as well as the granulometric fraction of the soil with potential to supply K to the plants from two basaltic Oxisols (Hapludox and Kandiudox). The mineralogical analyses of the granulometric fractions of the Hapludox soil revealed the probable occurrence of a mica mineral in the fine silt and coarse clay fractions, while feldspar minerals occurred in the sand, coarse silt, and fine silt fractions. In the Kandiudox soil, a probable mica mineral was observed in the coarse silt, fine silt, and coarse clay fractions, whereas feldspar minerals were observed in the sand and silt fractions. In both soils, the presence of a 2:1 clay mineral with hydroxy interlayer material (2:1 EHI) was also observed. This clay mineral has the basic structure of a smectite mineral. The coarse clay fraction of both soils presented the strongest evidences of the presence of K-bearing minerals, representing the most promising fraction for K supply to plants.

Persistência dos efeitos da escarificação sobre a compactação de Nitossolo sob plantio direto em região subtropical úmida

O objetivo deste trabalho foi avaliar a persistencia dos efeitos da escarificacao sobre a compactacao de Nitossolo Vermelho, manejado sob plantio direto (PD), na regiao subtropical umida do Brasil. O experimento foi realizado em blocos ao acaso, com quatro repeticoes e seis tratamentos, constituidos pelo tempo de manutencao do solo sob PD apos escarificacao: PD continuo por 24 meses apos escarificacao, realizada em setembro de 2009; PD continuo por 18 meses apos escarificacao, realizada em marco de 2010; PD continuo por 12 meses apos escarificacao, realizada em setembro de 2010; PD continuo por seis meses apos escarificacao, realizada em marco de 2011; plantio realizado em solo recem escarificado, em setembro de 2011; e PD continuo e sem escarificacao (testemunha). As especies cultivadas na area foram: milho, safra 2009/2010; trigo, em 2010; soja, safra 2010/2011; centeio, em 2011; e milho, safra 2011/2012. Os efeitos dos tratamentos foram avaliados a partir de parâmetros fisicos do solo e de parâmetros morfologicos e produtivos da cultura do milho, na safra 2011/2012. A escarificacao do Nitossolo sob plantio direto, em regiao de clima subtropical umido, nao aumenta a produtividade de graos de milho, e os seus efeitos sobre a estrutura do solo nao persistem por mais de 18 meses.

Efeito de semeadora com haste sulcadora para ação profunda em solo manejado com plantio direto

The adoption of no-till in the humid subtropical region of Brazil based on only two precepts of conservation agriculture, soil disturbance restricted to the crop row and crop residue maintained as soil cover, has led to stratification of soil chemical properties in the 0-20 cm soil layer and physical degradation of the subsurface layer (from approximately the 5-20 cm depth), which may make for lower yields during short term droughts. The aim of this study was to evaluate the residual effect of a seed drill/fertilizer applicator equipped with fixed shanks, set at four different depths, for the sowing of maize (Zea mays L.), in mitigation of chemical and physical problems in a Latossolo Vermelho distrofico humico (Rhodic Hapludox) under no-till for more than ten years. The treatments were: T1 = shank extremity at 5 cm depth; T2 = shank extremity at 10 cm depth; T3 = shank extremity at 15 cm depth; and T4 = shank extremity at 17 cm depth. The crop profile method was used to evaluate soil physical properties (bulk density, total porosity, macroporosity, and soil resistance to penetration) at eight and ten months after sowing the maize. The chemical properties (pH in water; available P and K; exchangeable Ca, Mg, and Al; potential acidity; and organic matter) were evaluated in layers every 2.5 cm from the 0-22.5 cm depth. The seed drill/fertilizer applicator equipped with fixed shanks for ripping the soil was able to mitigate soil physical and chemical problems, both at eight and 12 months after sowing.

Densidade de um planossolo sob sistemas de cultivo avaliada por meio da tomografia computadorizada de raios gama

A sustentabilidade do arroz (Oryza sativa L.) irrigado em solos de varzea esta alicercada na utilizacao da rotacao e sucessao de culturas, fundamentais para o controle do arroz-vermelho e preto. Os reflexos sobre os atributos dos solos de varzea merecem estudos em especial sobre a compactacao do solo. O objetivo deste trabalho foi identificar camadas compactadas em Planossolo submetido a diferentes sistemas de cultivo e preparo, avaliando-se a densidade do solo (Ds) pela Tomografia Computadorizada de Raios Gama (TC). A analise foi realizada em um experimento de longa duracao, conduzido de 1985 a 2004, na Estacao Experimental da Embrapa Clima Temperado, Capao do Leao, RS, num delineamento experimental em blocos ao acaso, com sete tratamentos, cada um com quatro repeticoes (T1 - um ano de arroz com preparo convencional do solo seguido de dois anos de pousio; T2 - cultivo continuo de arroz com preparo convencional do solo; T4 - rotacao de arroz e soja (Glycine max L.) com preparo convencional do solo; T5 - rotacao de arroz, soja e milho (Zea maiz L.) em preparo convencional do solo; T6 - plantio direto de arroz no verao em sucessao do azevem (Lolium multiflorum L.) no inverno; T7 - rotacao de arroz sob plantio direto e soja sob preparo convencional do solo; T8 - testemunha: solo sem cultivo). A Tomografia Computadorizada de Raios Gama permitiu detectar que o plantio direto de arroz no verao em sucessao do azevem no inverno nao resultou na formacao de camadas compactadas; a utilizacao de dois anos de pousio, no sistema de producao de arroz irrigado, nao foi suficiente para evitar a formacao de uma camada superficial compactada; e a rotacao de arroz, soja e milho com preparo convencional do solo apresentou duas camadas compactadas (0,0 a 1,5 cm e 11 a 14 cm), indicando que essas podem limitar a producao agricola nesse sistema de producao em Planossolos.

Perennial grasses for recovery of the aggregation capacity of a reconstructed soil in a coal mining area in southern Brazil

The construction of a soil after surface coal mining involves heavy machinery traffic during the topographic regeneration of the area, resulting in compaction of the relocated soil layers. This leads to problems with water infiltration and redistribution along the new profile, causing water erosion and consequently hampering the revegetation of the reconstructed soil. The planting of species useful in the process of soil decompaction is a promising strategy for the recovery of the soil structural quality. This study investigated the influence of different perennial grasses on the recovery of reconstructed soil aggregation in a coal mining area of the Companhia Riograndense de Mineracao, located in Candiota-RS, which were planted in September/October 2007. The treatments consisted of planting: T1- Cynodon dactylon cv vaquero; T2 - Urochloa brizantha; T3 - Panicum maximun; T4 - Urochloa humidicola; T5 - Hemarthria altissima; T6 - Cynodon dactylon cv tifton 85. Bare reconstructed soil, adjacent to the experimental area, was used as control treatment (T7) and natural soil adjacent to the mining area covered with native vegetation was used as reference area (T8). Disturbed and undisturbed soil samples were collected in October/2009 (layers 0.00-0.05 and 0.10-0.15 m) to determine the percentage of macro- and microaggregates, mean weight diameter (MWD) of aggregates, organic matter content, bulk density, and macro- and microporosity. The lower values of macroaggregates and MWD in the surface than in the subsurface layer of the reconstructed soil resulted from the high degree of compaction caused by the traffic of heavy machinery on the clay material. After 24 months, all experimental grass treatments showed improvements in soil aggregation compared to the bare reconstructed soil (control), mainly in the 0.00-0.05 m layer, particularly in the two Urochloa treatments (T2 and T4) and Hemarthria altissima (T5). However, the great differences between the treatments with grasses and natural soil (reference) indicate that the recovery of the pre-mining soil structure could take decades.

Balanço geoquímico de solos derivados de rochas básico-ultrabásicas no ambiente subtropical do Rio Grande do Sul

The mass balance of weathering of soils derived from basic-ultrabasic rocks under the subtropical climate of southern Brazil, the least weathered soils found to date in the Rio Grande do Sul state, showed a higher relative concentration of the mobile elements in the surface horizons than in the subsurface horizons. These features, associated to the soil mineralogy and morphology, indicate the occurrence of erosive-depositional events in a pedogenetically recent past as well as a main contribution from less weathered materials to the mineral composition of the surface horizons. These erosive events and the profiles surface renewal explain the early stage of development of these soils and their chemical and mineralogical similarity to soils derived from basic-ultrabasic rocks of temperate regions.

Atributos químicos e biológicos de um solo de várzea afetados pela sistematização do terreno

The objective of this work was to evaluate the relationship between soil chemical and biological attributes and the magnitude of cuts and fills after the land leveling process of a lowland soil. Soil samples were collected from the 0 - 0.20 m layer, before and after leveling, on a 100 point grid established in the experimental area, to evaluate chemical attributes and soil microbial biomass carbon (MBC). Leveling operations altered the magnitude of soil chemical and biological attributes. Values of Ca, Mg, S, cation exchange capacity, Mn, P, Zn, and soil organic matter (SOM) decreased in the soil profile, whereas Al, K, and MBC increased after leveling. Land leveling decreased in 20% SOM average content in the 0 - 0.20 m layer. The great majority of the chemical attributes did not show relations between their values and the magnitude of cuts and fills. The relation was quadratic for SOM, P, and total N, and was linear for K, showing a positive slope and indicating increase in the magnitude of these attributes in cut areas and stability in fill areas. The relationships between these chemical attributes and the magnitude of cuts and fills indicate that the land leveling map may be a useful tool for degraded soil recuperation through amendments and organic fertilizers.

Biological and physical quality of a mined soil under revegetation with perennial grasses

The objective of this work was to evaluate a population of mites and springtails and a physical condition of a mined soil revegeted with different species of perennial grasses. The treatments evaluated were: Urochloa brizantha, Hemarthria altissima, Paspalum notatum, Cynodon dactylon and Spontaneous vegetation. For comparative effects a natural soil were used as reference. In 2014, 56 soil samples were collected in the 0.00-0.10 m layer for the determination of the population of mites and springtails, the physical attributes and the organic carbon content. The Hemarthria altissima was the most prominent plant species among perennial grasses, to date, providing an average density of mites and springtails very close to the natural soil. Among the physical attributes, bulk density showed the most sensitive variable the changes promoted by plant species, after 11 years of revegetation.

FRI0217 Prospective Study of Pregnant Women with Axial Spondyloarthritis: Is Asdas Adequate to Measure Disease Activity in this Population?

Background The effect of pregnancy on spondyloarthropathies such as ankylosing spondylitis (AS) or axial psoriatic arthritis (PsA) is not clear. Some reports claim a beneficial effect during pregnancy [1] while others mention there is no particular effect or that there might be an aggravation of symptoms [2,3,4]. The methods of measuring disease activity in AS are not yet validated for pregnancy and their applicability in this context is questionable. C-Reactive protein (CRP) and especially erythrocyte sedimentation rate (ESR) are increased during normal pregnancy [5,6] and this might affect disease activity scores and their interpretation. Ankylosing Spondylitis Disease Activity Score (ASDAS) is not yet proven to correlate with disease activity in AS and other spondyloarthropathies with axial involvement. Objectives To study and characterize a population of women with axial spondyloarthritis before, during pregnancy and post-delivery and to evaluate disease activity indexes in this population. Methods We prospectively evaluated 30 women, with a mean age of 31.5±4.7 years, 25 with the diagnosis of ankylosing spondylitis and 5 with axial psoriatic arthritis. AS/PsA patients were considered active if the visual analogue scale (VAS) of nocturnal back pain and fatigue ≥30 plus morning stiffness >30 minutes, and/or ≥1 swollen or tender joint or ≥2 active enthesitis or dactylitis or Psoriasis Area Severity Index (PASI) ≥10 or exacerbation of associated inflammatory bowel disease. ASDAS-CRP/ESR were calculated. Statistical treatment was performed using SPSS-20. Results Before conception, disease was active in 3 out of 30 AS/PsA patients, with an overall mean ASDAS-ESR/CRP of 0.49/0.11. During pregnancy there was an increase in disease activity until the 3rd trimester (p=0,005) and after labour (p=0,025). During the 2nd trimester two thirds of all patients had an active disease. Ultrasound-verified hip synovitis was found in nine patients, all symptomatic and requiring prednisolone treatment. Eigth women stopped working due to disease activity. ASDAS-ESR/CRP was correlated with disease activity (p=0,003, p=0,012, respectively). Conclusions Disease activity during pregnancy is increased in AS and axial PsA. ASDAS seems like a promising tool for the follow-up of these patients during pregnancy. References Lui NL, Haroon N, Carty A, Shen H, Cook RJ, Shanmugarajah S, Gladman DD, Inman RD. Effect of pregnancy on ankylosing spondylitis: a case-control study. J Rheumatol. 2011 Nov;38(11):2442-4. Østensen M, Villiger PM, Förger F. Interaction of pregnancy and autoimmune rheumatic disease. Autoimmun Rev. 2012 May;11(6-7):A437-46. Ostensen M. The effect of pregnancy on ankylosing spondylitis, psoriatic arthritis, and juvenile rheumatoid arthritis. Am J Reprod Immunol. 1992 Oct-Dec;28(3-4):235-7. Gromnica-Ihle E, Ostensen M. Pregnancy in patients with rheumatoid arthritis and inflammatory spondylarthropathies. Z Rheumatol. 2006 May;65(3):209-12,214-6. van den Broe NR, Letsky EA. Pregnancy and the erythrocyte sedimentation rate. BJOG. 2001 Nov;108(11):1164-7 Salawu L, Durosinmi MA. Erythrocyte rate and plasma viscosity in health and disease. Niger J Med. 2001 Jan-Mar;10(1):11-3. Disclosure of Interest None declared

FRI0081 Prospective Study of Pregnant Women with Rheumatoid Arthritis: Can we Apply DAS28 to this Population?

Background Pregnancy has a positive imunomodulador effect in Rheumatoid Arthritis (RA) patients [1,2,3]. In postpartum, disease relapse is reported to occur in as much as 92% of cases [2]. The methods of measuring disease activity in RA are not yet validated for pregnancy and their applicability in this context is questionable. C-Reactive protein (CRP) and especially erythrocyte sedimentation rate (ESR) are increased during normal pregnancy [4,5] and this might affect disease activity scores and their interpretation. Disease Activity Score (DAS)28 is not yet proven to correlate with disease activity in pregnant RA patients. Objectives To study and characterize a population of women with rheumatoid arthritis before, during pregnancy and post-delivery and to evaluate disease activity indexes in this population. Methods We prospectively evaluated 25 women with rheumatoid arthritis, with a mean age of 32.3±4.3 years and mean disease duration of 6.3±4.4 years. We considered RA patients with >1 swollen or tender joint (68 joints) and a visual analogue scale (VAS) of pain or disease ≥10 as active. DAS28(4v)-CRP and DAS28(4v)-ESR were calculated. Statistical treatment was performed using SPSS-20. Results Before pregnancy, patients had a mean DAS28(4v)-ESR of 2,42 (remission), yet during the first, second and third trimesters, mean DAS28(4v)-ESR was above 2,6 and below 3,2 suggesting low disease activity. Post partum, DAS28(4v)-ESR returned to remission values (2,29). The swollen and tender 68 joint count, pain VAS and disease VAS were low during the whole pregnancy for most patients and low in the overall patient mean. During pregnancy, using our considerations for disease activity, there was a reduction in RA activity from the first evaluation until the 3rd trimester (p=0,014). No women stopped working due to active RA. DAS28(4v)-ESR/CRP were not correlated with disease activity. Conclusions Disease activity during pregnancy is decreased in RA. DAS28(4v)-CRP seemed better than DAS28(4v)-ESR in measuring disease activity, but neither correlated with our clinical evaluation. DAS28 values were probably elevated due to the increased levels of both CRP and ESR during pregnancy. References Østensen M, Villiger PM, Förger F. Interaction of pregnancy and autoimmune rheumatic disease. Autoimmun Rev. 2012 May;11(6-7):A437-46. Zrour SH, Boumiza R, Sakly N, Mannai R, Korbaa W, Younes M, Bejia I, Touzi M, Bergaoui N. The impact of pregnancy on rheumatoid arthritis outcome: the role of maternofetal HLA class II disparity. Joint Bone Spine. 2010 Jan;77(1):36-40. Nelson JL, Hughes KA, Smith AG, Nisperos BB, Branchaud AM, Hansen JA. Remission of rheumatoid arthritis during pregnancy and maternal-fetal class II alloantigen disparity. Am J Reprod Immunol. 1992 Oct-Dec;28(3-4):226-7. van den Broe NR, Letsky EA. Pregnancy and the erythrocyte sedimentation rate. BJOG. 2001 Nov;108(11):1164-7 Salawu L, Durosinmi MA. Erythrocyte rate and plasma viscosity in health and disease. Niger J Med. 2001 Jan-Mar;10(1):11-3. Disclosure of Interest None declared