reSUmo decorrente dos sistemas de manejo empregados no solo, como o sistema de preparo convencional (SPC) versus o sistema de plantio direto de hortaliças (SPDH), modificações nos atributos edáficos ocorrem; por exemplo, nos índices de agregação do solo e seu teor de carbono orgânico total (COT). Objetivaram-se quantificar os teores de COT e avaliar os índices de agregação do solo e a distribuição dos agregados por classes de diâmetro sob cultivo de cebola em SPdH e SPC, comparados a uma área de mata adjacente em ituporanga, SC. os tratamentos constituíram-se da semeadura de plantas de cobertura, solteiras e consorciadas, em SPdH: vegetação espontânea (VE); 100 % aveia; 100 % centeio; 100 % nabo-forrageiro; consórcio de nabo-forrageiro (14 %) e centeio (86 %); e consórcio de nabo-forrageiro (14 %) e aveia (86 %). adicionalmente, foram avaliadas uma área de cultivo de cebola em SPC por ±37 anos e uma área de mata (floresta secundária; ±30 anos), ambas adjacentes ao experimento. Em setembro de 2013, cinco anos após a implantação dos tratamentos com plantas de cobertura, foram coletadas amostras indeformadas do solo nas camadas de 0-5, 5-10 e 10-20 cm e separados os agregados para avaliar a estabilidade via úmida. Nos agregados, foi quantificado o COT;Recebido para publicação em 7 de novembro de 2014 e aprovado em 10 de março de 2015.

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In this paper we explore the accumulation of different phosphorus (P) fractions in soil submitted to successive applications of pig slurry (PS) and deep pig litter (DL). After 88 months of no-till crop cycles, soil samples were collected in the following treatments: control (C), PS applications equivalent to 90 and 180 kg N ha -1 (PS90 and PS180), and DL applications equivalent to 90 and 180 kg N ha -1 (DL90 and DL180). The cumulative application of P of the C, PS90, PS180, DL90 and DL180 treatment was 0, 303, 606, 825 and 1650 kg P ha -1 , respectively. The soil samples were then submitted to P chemical fractionation. Successive applications of 303 and 606 kg P ha -1 in PS form and 825 and 1.650 kg P ha -1 in DL form increased P levels down to 20 cm depth, especially in the labile inorganic fraction extracted by anion exchange resin and 0.5 M NaHCO 3 and to a lesser extent extracted by 0.1 M NaOH. Successive additions of PS180 and DL180 increased the levels of organic P extracted by 0.5 M NaHCO 3 , 0.1 M NaOH and 0.5 M NaOH, and successive applications of PS and DL caused P accumulation in the soil profile, especially in labile fractions. This increased the availability to plants, but also increases the potential for environmental contamination.

Frequent applications of copper (Cu)-based fungicides on vines causes the accumulation of this metal in vineyard soils, which can cause toxicity in young vines. However, liming may reduce these toxic effects. The present study aimed to evaluate the effects of Cu toxicity on the root anatomy of young vines and the alleviation of Cu toxicity by lime applications to contaminated sandy soil. The treatments consisted of the addition of lime (0.0, 1.5 and 3.0 Mg ha(-1)) and two Cu concentrations (0 and 50 mg kg(-1)) to Typic Hapludalf soil. Young vines 'Niágara Branca' (Vitis labrusca L.) were obtained by micropropagation and cultivated for 70 days. The young vines grown with Cu and without liming presented a disorganized root structure; reduced root cap size; increased diameter (47%), cortex area (128%), vascular cylinder area (93%), and number of cortical layers and cells containing phenolic compounds (132%); and reduced root (41%), stem (44%) and leaf dry mass (21%) and height increase (55%). Moreover, Cu exposure reduced Ca concentrations (13%) and increased Cu concentrations (371%) in the roots. Liming, primarily with the highest tested dose, increased the soil pH (from 4.4 to 5.4-6.1), decreased the Cu concentration in the soil (extracted by CaCl2), increased the calcium (Ca) and magnesium (Mg) uptake by plants, prevented root anatomical changes and benefited young vine growth in soil with higher Cu concentrations.

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SUMMARYSuccessive applications of liquid swine waste to the soil can increase the contents of total organic carbon and nutrients and change acidity-related soil chemical properties. However, little information is available on the effects of swine waste application in solid form, as of swine deep-litter. The objective of this study was to evaluate alterations of organic carbon and acidity-related properties of a soil after eight years of pig slurry and deep-litter application. In the eighth year of a field experiment established in Braço do Norte, Santa Catarina (SC) on a sandy Typic Hapludalf samples were taken (layers 0-2.5; 2.5-5; 5-10; 10-15; 15-20 and 20-30 cm) from unfertilized plots and plots with pig slurry or deep-litter applications, providing the simple or double rate of N requirement of Zea mays and Avena strigosa in rotation. Soil total organic carbon, water pH, exchangeable Al, Ca and 0-2,5, 2,5-5, 5-10, 10-15, 15-20 e 20-30 cm, em

IMatéria seca de plantas de cobertura, produção de cebola e atributos químicos do solo em sistema plantio direto agroecológico ABSTRACT The cultivation and deposition of waste from cover crops in no-tillage can affect soil chemical attributes and onion yield. The aim of this study was to evaluate the dry matter yield of plant species from winter cover crops, onion yield and chemical attributes of soil in agroecological no-tillage system. The experiment was carried out at EPAGRI Experimental Station in Ituporanga (SC) under Humic