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SUMMARYLong-term applications induced an increase in organic matter in the deeper layers. However, the effect of this residue on the potential CEC was less significant and restricted to the surface layers.Index terms: water pH, base saturation, Al saturation, soil organic matter, organic waste. 0-2, 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-18, 18-20, 20-25, 25-30, 30-35, 35-40, 40-50 e 50-60 RESUMO: ATRIBUTOS QUÍMICOS RELACIONADOS A ACIDEZ EM SOLO COM SUCESSIVAS APLICAÇÕES DE DEJETO LÍQUIDO DE SUÍNOS

Resumo -O objetivo deste trabalho foi quantificar as frações de acumulação de fósforo em solo submetido a sucessivas aplicações de dejetos líquidos de suínos (DLS) em sistema de plantio direto. Em Santa Maria, RS, doses de 0, 20, 40 e 80 m 3 ha -1 de DLS foram distribuídas a lanço por sete anos agrícolas, antes do plantio de cada cultivo de inverno ou verão, em Argissolo Vermelho arenoso, totalizando 0, 584, 1.168 e 2.336 kg ha -1 de P aplicado via dejetos. O solo foi coletado nas camadas 0-2, 4-6, 8-10, 14-16 e 20-25 cm, e submetido ao fracionamento químico de P. A adição do DLS ao solo durante sete anos aumentou o teor de P até 25 cm de profundidade, principalmente nas frações inorgânicas extraídas por resina trocadora de ânions, NaHCO 3 0,5 mol L -1 e NaOH 0,1 mol L -1. As aplicações não aumentaram os teores de P orgânico extraído por NaHCO 3 0,5 mol L -1 , mas sim as frações orgânicas extraídas por NaOH 0,5 e 0,1 mol L -1 . O DLS adicionado ao solo por longo período pouco afeta a partição de P em frações inorgânicas e orgânicas. As sucessivas aplicações de DLS aumentam o acúmulo de P em frações predominantemente lábeis no solo, o que representa um risco potencial para contaminação de águas superficiais e subsuperficiais.Termos para indexação: esterco de suínos, fracionamento de fósforo, fósforo lábil, fósforo orgânico, risco de eutrofização, sistema de cultivo. Phosphorus fractions in soil after sucessive pig slurry applications in no-tillage systemAbstract -The objective of this work was to quantify the accumulation of phosphorus fractions in the soil subjected to successive pig slurry applications in a no-tillage system. At Santa Maria, Rio Grande do Sul state, Brazil, 0, 20, 40 and 80 m 3 ha -1 doses of pig slurry were broadcasted for seven years on Argissolo Vermelho arenoso (Arenic Hapludult) before sowing each winter or summer crop, totalizing 0, 584, 1,168 and 2,336 kg ha -1 of P from pig slurry. Soil samples were collected in 0-2, 4-6, 8-10, 14-16 and 20-25 cm layers and submitted to P fractionation. Applications of pig slurry during seven years increased P contents to a depth of 25 cm, especially in the inorganic fractions extractable by anion exchange resin, NaHCO 3 0.5 mol L -1 and NaOH 0.1 mol L -1 . Pig slurry doses did not increase P content in organic fractions extracted by NaHCO 3 0.5 mol L -1 , but increased the content of organic fractions extracted by NaOH 0.5 e 0.1 mol L -1. Pig slurry applied to soil for large period has little effect on the P partition in inorganic and organic fractions. Successive pig slurry applications increase P contents in the soil predominantly in labile fractions, which can represent a potential risk for waterbeds contamination.

Aims This study investigated Cu uptake and accumulation as well as physiological and biochemical changes in grapevines grown in soils containing excess Cu. Methods The grapevines were collected during two productive cycles from three vineyards with increasing concentrations of Cu in the soil and at various growth stages, before and after the application of Cu-based fungicides. The Cu concentrations in the grapevine organs and the macronutrients and biochemical parameters in the leaf blades were analyzed.Results At close to the flowering stage of the grapevines, the concentration and content of Cu in the leaves were increased. However, the Cu concentrations in the roots, stem, shoots and bunches did not correlate with the metal concentrations in the soil. The application of Cu-based fungicides to the leaves increased the Cu concentrations in the shoots, leaves and rachis; however, the effect of the fungicides on the Cu concentration in the berries was not significant. The biochemical analyses of the leaf blades demonstrated symptoms of oxidative stress that correlated with the Cu concentrations in soil. Conclusions The increased availability of Cu in soil had a slight effect on the levels and accumulation of Cu in mature grapevines during the productive season and did not alter the nutritional status of the plant. However, increased Cu concentrations were observed in the leaves. The evidence of oxidative stress in the leaves correlated with the increased levels of Cu in soil.

SUMMARY RESUMO: NUTRIENTES EM CAMADAS DE SOLO SUBMETIDO A SUCESSIVAS APLICAÇÕES DE DEJETO LÍQUIDO DE SUÍNOS E SOB PLANTIO DIRETO 0-2, 2-4, 4-6, 6-8, 8-10, 10-12, 12-14, 14-16, 16-18, 18-20, 20-25, 25-30, 30-35, 35-40, 40-50 e 50-60

Nitrogen from cover crop residues decomposing on the soil surface may contribute to 'Niagara Rosada' grape nutrition. This study estimated the recovery of N from the decomposition of rye (Secale cereale) residues deposited on the soil surface in vineyards. Rye litter labeled with 15 N was applied in July 2008 on the soil surface of a 'Niagara Rosada' grape (Vitis labrusca) vineyard in Bento Gonç alves in the southern region of Brazil. In January 2009 and 2010, 'Niagara Rosada' grape plant organs were sampled, and in January 2010, soil samples were collected in different depths. Total N and 15 N were analyzed in the plant tissue and soil samples. The N derived from the rye litter added to the soil surface was mostly accumulated in the annual and perennial organs of the 'Niagara Rosada' grape at a similar percentage. Most of the N contained in 'Niagara Rosada' grape organs was derived from different N sources rather than rye litter. Thus, the N derived from rye litter apparently contributed little to 'Niagara Rosada' grape nutrition in the short time period.

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RESUMOO estudo em pauta teve como objetivo analisar a distribuição da quantidade diária de precipitação e do número de dias com chuva e determinar a variação da probabilidade de ocorrência de precipitação diária, durante os meses do ano, em Santa Maria, RS. Os dados de precipitação utilizados foram obtidos durante 36 anos de observação, na Estação Climatológica do 8º Distrito de Meteorologia, localizada na Universidade Federal de Santa Maria (29°43' 23" de latitude Sul e 53°43' 15" de longitude Oeste, altitude 95 m). Analisaram-se as seguintes funções de distribuição de probabilidade: gama, Weibull, normal, log-normal e exponencial. As funções que melhor descreveram a distribuição das probabilidades foram gama e Weibull. O maior número de dias com chuva ocorreu durante os meses de inverno porém o volume de precipitação é menor nesses dias, resultando em total mensal semelhante para todos os meses do ano.Palavras-chave: função de distribuição, precipitação pluvial, gama, Weibull Analysis of rainfall distribution for Santa Maria, RS, Brazil ABSTRACTThe objectives of this study were to analyze the distribution of total daily rainfall data and the number of rainy-days, and to determine the probability variation of daily precipitation during the months of the year in Santa Maria, Rio Grande do Sul State, Brazil. A 36-year rainfall database measured at the Climatological Station of 8 th District of Meteorology, located in Santa Maria Federal University (29°43' 23" S and 53°43' 15" W) were used in the study. The following probability distribution functions were tested: gamma, Weibull, normal, lognormal and exponential. The functions that best described the frequency distribution were gamma and Weibull. There were more number of rainy days in the winter, but with less amount of rainfall, resulting in similar monthly total precipitation for the twelve months of the year.