Avaliação de níveis de gesso para correção de sodicidade de solos 1 RESUMOUm experimento em colunas de solo foi conduzido no Laboratório de Mecânica do Solo e Aproveitamento de Resíduos da Universidade Federal Rural de Pernambuco, com o objetivo de se avaliar os efeitos dos níveis da necessidade de gesso determinada conforme método de Schoonover M-1. O delineamento utilizado foi de blocos ao acaso em esquema fatorial do tipo 2 x 6 com 3 repetições. Os tratamentos consistiram de duas amostras de solos salino-sódicos (S1 e S2) e seis níveis da necessidade de gesso (25, 50, 75, 100, 125 e 150%). Após aplicação dos níveis de gesso e da lixiviação dos sais, ocorreu aumento da permeabilidade, redução da condutividade elétrica e, com a aplicação dos níveis 100, 125 e 150% da necessidade de gesso, houve correção da sodicidade dos solos.Palavras-chave: salino-sódico, necessidade de gesso, Schoonover M-1 Evaluation of gypsum levels for correction of soil sodicity ABSTRACT An experiment in soil columns was carried out at the Laboratory of Soil Mechanics and Use of Residues of the Federal Rural University of Pernambuco, with the objective to evaluate the effect of different levels of gypsum requirement according to method of Schoonover M-1. The experiment was planned in random blocks in a 2 x 6 factorial with 3 replications. The treatments consisted of two samples of saline-sodic soils (S1 and S2) and six levels of the gypsum requirement (25, 50, 75, 100, 125 and 150%). After application of the gypsum levels and leaching an increase in the permeability and reduction of electrical conductivity were observed and with the application of gypsum levels equivalent to 100, 125 and 150% of requirement, the correction of the sodicity of soil was observed.
This paper describes the epidemiological, clinical and pathological aspects of an avian encephalomyelitis (AE) outbreak in commercial laying hens in Northeastern Brazil. The disease affected 23,409 layers (from day one until 100 weeks) leading to mortality of 16.5% (5,049/30,600) of the flock. Twenty laying hens were clinically examined, and blood samples were collected and tested by Enzyme-Linked Immunosorbent Assay (ELISA). Five laying hens with neurological signs were necropsied and samples of the brain, cerebellum, spinal cord, sciatic nerve, heart, ceca tonsils, proventriculus and liver were collected, fixed in formalin buffered solution and processed according to routine methods for histological examination. Clinical signs were observed in approximately 60% of the chicken flock and included depression, ataxia, head and neck tremors, head tilt, motor incoordination and corneal opacity and of lens. All laying hens presented seroconversion for AE, with a geometric mean titer (GMT) of 6,854 and CV of 9.6%. At necropsy, there were bilateral opacity of the cornea and lens and the blood vessels of the cerebral cortex were hyperemic. The main microscopic lesions in the central nervous system consisted of red and shrunken neurons in the cerebral cortex, cerebellum and spinal cord. Significant areas of gliosis were observed in the cerebral cortex and in the molecular layer of the cerebellum. Hyperplasia of the proventricular lymphoid tissue and the ceca tonsils were observed with different degrees of intensity. In Northeastern Brazil, there haven't been previous reports of AE in commercial laying hens and this outbreak possibly occurred by inefficient immunization of laying breeders at the genetic supply company.
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