ABSTRACT Soil quality can be understood as its capacity to provide several essential services within the ecosystem and has been used to understand the impact of different managements, providing information that proves the benefits and your maintenance of the agroecosystem. To understand the impact of different managements, this study aimed to compare the chemical, physical, and biological soil properties in pasture areas managed with different recovery times in an integrated crop-livestock system about perennial pastures and secondary forest. The following management systems were evaluated: Secondary Forest (SF), Perennial Pasture (PP), pasture recovered to five years through the intercropping corn + Brachiaria brizantha (Palisade grass) (ICL5), and pasture recovered to eight years through the intercropping corn + Brachiaria brizantha (Palisade grass) (ICL8). Different soil properties were evaluated, namely: Chemical: pH, H+Al, Al 3+ , P, K + , Ca 2+ , Mg 2+ , TOC, SB, CEC, V, and m; Physical: soil bulk density (Bd), total porosity (Tp), macroporosity (Ma), microporosity (Mi), soil resistance to penetration (Pr), and gravimetric soil water content (GWc); and biological: soil microbial biomass carbon (SMB-C), basal soil respiration (BSR), metabolic quotient (qCO 2 ), and microbial quotient (qMic). Perennial pasture and ICL8 areas were the ones that most contributed to the increase in nutrients (Ca 2+ , Mg 2+ , and K + ), TOC and sorption complex. The ICL8 area showed the best results in soil physical variables Ma, Tp, Pr, and GWc were the best results for the ICL8 area. Secondary forest and ICL8 areas presented the best results from SMB-C and qMic. Between periods of pasture recovery through the integration of crops and livestock, the longer the recovery time, the greater its beneficial effects on the different chemical, physical and biological soil properties, overcoming secondary forest and perennial pasture.

ABSTRACT. In Maranhão State, Brazil, soils are naturally acidic, nutrient-deficient, and prone to cohesion and erosion. Removing the natural cover to establish pastures causes physical, chemical, and biological changes in the soil. Therefore, this study aimed to evaluate the contents and stocks of carbon (C), nitrogen (N), and particle-size fractions of soil organic matter (SOM) in pastures with different years of recovery, and compare them with a secondary forest in the Legal Amazon. Four treatments were evaluated: secondary forest, perennial pasture, and perennial pastures recovered for five years and eight years, both of the latter through corn + brachiaria intercropping. The contents and stocks of total organic carbon, total nitrogen, C, and N from the soil organic matter particle-size fractions, as well as the carbon management indexes (CMI) of the 0.00-0.10, 0.10-0.20, 0.20-0.30, and 0.30-0.40 m layers were evaluated. The perennial pasture environment presented the highest total soil C and N contents; however, when observing the granulometric fractions and CMI, these increases were qualitative in relation to the secondary forest. Pasture recovery over eight years contributed to an improvement of soil quality similar to secondary forest, indicating that an increase in SOM quality, quantity, and recovery time related to increased pasture capacity to accumulate C and N in the soil.

ABSTRACT Soil aggregates and their stability affect a wide range of soil properties. This study aimed to (a) verify whether biogenic aggregation provides higher macro- and microaggregate stabilization, and (b) evaluate whether biogenic aggregates are associated with higher labile organic carbon and glomalin contents. Three management systems were evaluated (permanent pasture, PP; no-tillage system, NT; and no-tillage + Brachiaria system, NT+B) as well as a reference area (Atlantic Forest biome vegetation, NF). According to their origin or formation pathway, the aggregates were separated, identified, and classified as biogenic (formed by biological processes) and physicogenic (resulting from chemical and physical actions). The PP system provided the greatest stabilization of the macroaggregates, regardless of the formation pathway, as reflected by a greater mean weight diameter (MWD). The PP system also influenced the degree of microaggregate stability by increasing the bond strength and reducing the dispersion of the clay fraction. Finally, the PP system elevated the contents of labile organic carbon (POXC), easily extractable glomalin (GRSP-EE), and total glomalin (GRSP-T) under both formation pathways. The NT+B system favored the stabilization of macroaggregates, especially in the subsurface soil layer, compared with the NT area. In the aggregates of the NT and NT+B areas, the highest values observed were for water-dispersible clay (WDC) and the lowest values observed were for non-dispersible clay (NDC), a pattern opposite to that observed in the aggregates of the PP and NF areas. In the biogenic aggregates of all areas, a high POXC content was quantified, and biogenic aggregation proportionally increased the values of MWD, GRSP-EE, and GRSP-T relative to physicogenic aggregation. The results showed that grain production systems, pasture systems, and non-anthropized environments differentially influenced aggregation and the concentrations of organic fractions associated with aggregate stability. This study highlights the need for future studies using these indicators to monitor the quality of soils, especially those with sandy texture, which are considered more fragile.

Resumo O objetivo deste trabalho foi quantificar os teores de C das frações químicas e físicas da MOS em diferentes sistemas de manejo em um Argissolo textura arenosa. O estudo foi realizado em uma área de referência de Mata Nativa (MN) e três áreas manejadas: pastagem permanente (PP), sistema plantio direto (SPD) e área de Reserva Particular de Patrimônio Natural em processo de regeneração natural (RPPN). Foram coletadas amostras de solos das camadas de 0-0,05, 0,05-0,10 e 0,10-0,20 m. Foi determinado a densidade do solo (Ds) os teores de carbono orgânico total (COT) o fracionamento químico da MOS com determinação dos teores de C dos ácidos fúlvicos (AF), ácidos húmicos (AH) e humina (HUM), com posteriores cálculos das relações AH/AF, EA/HUM, estoque (EstC), fracionamento físico-granulométrico e determinação dos teores de C da matéria orgânica particulada (C-MOP) e índice de manejo de carbono (IMC). Observou-se maiores teores de COT para a área de MN, especialmente nas camadas de 0-0,05 e 0,05-0,10 m. Os teores de C-HUM predominam em relação aos teores de C-AH e C-AF. Os teores de C-AH e de C-HUM foram superiores em MN e SPD. A MN apresentou maiores teores de C-MOP em todas as camadas avaliadas. Para o C-MOM a área de SPD foi superior as demais áreas manejadas. As áreas manejadas apresentaram valores de EstMOP inferiores à MN. Nas duas primeiras camadas, a área de MN apresentou maiores EstMOM. As áreas manejadas apresentaram valores inferiores de IMC em relação a MN. A área de SPD demonstrou que, mesmo em sucessão, contribui para melhoria da fração orgânica do solo ao longo do tempo de adoção, se aproximando às condições da MN. Já as áreas de PP e RPPN evidenciaram que o manejo inadequado favorece na diminuição da qualidade edáfica.

Abstract This study quantified the C content of the chemical and physical fractions of SOM in different management systems in an Argisoil of sandy texture. The study was carried out in a reference area of Native Forest (NF), and in three managed areas: Permanent Pasture (PP), No-Tillage System (NTS) and an area of Private Natural Heritage Reserve (PNHR) in the process of natural regeneration. Soil samples were collected in the layers 0.0-0.05, 0.05-0.10 and 0.10-0.20 m. We assessed the soil density (Sd), total organic carbon (TOC) content, chemical fractionation of SOM with determination of the C contents of the fulvic acids (FA), humic acids (HA) and humin (HUM), with subsequent calculations of the HA/FA ratios, AE/HUM, stock (StockC), physical granulometric fractionation and determination of C contents of particulate organic matter (C-POM) and carbon management index (CMI). Higher TOC contents were observed for the NF area. The C-HA and C-HUM contents were higher in the NF and NTS. NF showed higher C-POM levels in all layers evaluated. For the C-MOM, the NTS area was superior to the other managed areas. The managed areas had lower StockPOM values than the NF. The managed areas had lower CMI values in relation to NF. The NTS area showed that, even in crop succession, it contributes to the improvement of the soil organic fraction over the adoption time. On the other hand, the areas of PP and PNHR showed that inadequate management favors the reduction of edaphic quality.

Resumo O objetivo do presente trabalho foi determinar o fracionamento físico-granulométrico e avaliar o carbono mineralizável no interior e ao entorno de fragmentos florestais do bioma Mata Atlântica localizados no estado do Paraná. As amostras de solo foram coletas em três de três pontos internos dos fragmentos: borda (BO), metade do raio (MR) e centro (CF) e um ponto em áreas de sistema plantio direto (SPD) no entorno dos fragmentos, em quatro repetições. Foram determinados os teores de carbono orgânico total (COT), carbono da fração particulada (C-MOP) e da fração mineral (C-MOM), sendo calculados as %MOP e %MOM e os estoques de MOP (Est. MOP) e de MOM (Est. MOM), além dos índices: índice de estoque de carbono (IEC), labilidade (L), índice de labilidade (IL) e índice de manejo de carbono (IMC), avaliando ainda a emissão de CO2, diária e acumulada. Os maiores teores de COT foram observados no ponto CF. Os maiores teores de C-MOP foram observados nos pontos BO e CF do fragmento 1, no ponto CF do fragmento 2, e os maiores teores de C-MOM foram expressos no ponto CF de ambos os fragmentos. O IMC apresentou padrão distinto entre os fragmentos. As áreas de SPD apresentaram menor emissão de C-CO2, com 39,8% e 28,3% menos emissão total em relação ao CF. Os resultados do fracionamento físico-granulométrico mostram o ponto CF favorece a qualidade da MOS e a análise de carbono mineralizável indicou que a conversão de áreas nativas em SPD compromete a atividade microbiana do solo.

Abstract This study determined the physical granulometric fractionation evaluated the mineralizable carbon within and around forest fragments of the Atlantic Forest biome located in the state of Paraná. Soil samples were collected at three three internal points of the fragments: the edge (E), the half radius (HR) and the center (CF); and one point in no-tillage system (NTS) areas around the fragments, in four replicates. The contents of total organic carbon (TOC), particulate fraction carbon (C-POM) and mineral fraction (C-MOM) were determined, and the %POM and %MOM and the stocks of POM (StockPOM) and MOM (StockMOM) were calculated, in addition to the indices: carbon stock index (CSI), lability (L), lability index (LI) and carbon management index (CMI), also evaluating CO2 emission, daily and accumulated. The highest TOC levels were observed in the CF point. The highest C-POM contents were observed in the E and CF points of fragment 1, in the CF point of fragment 2, and the highest C-MOM contents were expressed in the CF points of both fragments. CMI showed a distinct pattern among the fragments. The NTS areas showed lower C-CO2 emissions, with 39.8% and 28.3% less total emission compared to CF. The results of physical granulometric fractionation show the CF point favors the quality of SOM and the mineralizable carbon analysis indicated that the conversion of native areas into NTS compromises soil microbial activity.

ABSTRACT The objective of this research was to assess soybean productivity in succession to cover crops grown during the winter, in addition to assessing physical properties macroporosity (Ma), microporosity (Mi), total porosity (Pt), soil density (Sd) and aggregate stability by means of the following variables: aggregate stability index, geometric mean diameter and weighted mean diameter after soybean crop cultivation. The experiment was conducted in the municipality of Quatro Pontes, PR, using a randomized-block design with six treatments and four replications. Treatments consisted of soybean crop grown on top of different cover plants’ haystack: black oat, black oat + forage turnip, forage turnip, black oat + forage pea, forage pea and control. Significant differences were observed for soil macroporosity and density. At the depth of 0.10 m, the highest Ma was observed in the area with oat and oat + turnip haystack. At other depths, all cover crops were superior to control. Treatments with cover crops were efficient in reducing soil PR. As for soil aggregation, the treatment with pea was superior to control for weighted mean diameter. The treatments with soybean sown after intercropping obtained greater mass, as well as higher productivity.

Resumo O objetivo deste trabalho foi avaliar a qualidade do solo a partir das frações químicas e oxidáveis da matéria orgânica (MOS) em áreas com diferentes sistemas de manejo. O trabalho foi realizado no Município de Guaíra, no Oeste do Paraná, em áreas com diferentes tempos de adoção do sistema plantio direto (SPD, 6, 14 e 22 anos), com sucessão das culturas soja (verão) e milho/trigo (inverno), além de áreas com 12 anos de SPD - no mesmo arranjo de sucessão - mais quatro anos de cultivo de braquiária (Urochloa ruziziensis) consorciada com milho (M+B) e com pastagem e mata nativa. As frações químicas de ácido fúlvico (AF), ácido húmico (AH) e humina (HUM) foram avaliadas, bem como as frações oxidáveis da MOS (F1, F2, F3 e F4), o carbono total (CT) e o estoque de carbono (C) nas frações húmicas. Os teores de CT aumentaram com o tempo de adoção do SPD, principalmente entre SPD6 e SPD22. Verificou-se predomínio da fração HUM e movimentação de AH e AF na camada de 0,0-0,4 m de profundidade. As frações oxidáveis apresentaram equilíbrio na distribuição do conteúdo de C, com maiores teores nas frações mais lábeis, em superfície. O cultivo com sucessão de culturas contribui para o aumento das frações mais lábeis, mas não para o aumento das frações mais recalcitrantes do C.

Abstract The objective of this work was to evaluate soil quality from soil organic matter (SOM) chemical and oxidizable fractions in areas with different management systems. The study was carried out in the municipality of Guaira, in the west of the state of the Paraná, Brazil, in areas with different adoption times of the no-tillage system (NT; 6, 14, and 22 years), with succession scheme of soybean (summer) and corn/wheat (winter) crops, besides areas with 12 years under NT - in the same succession scheme - plus four years of Urochloa ruziziensis intercropped with maize (M+U), and with pasture and native forest. The chemical fractions of fulvic acid (FA), humic acid (HA), and humin (HUM) were evaluated, as well as the oxidizable fractions of MOS (F1, F2, F3, and F4), total carbon (TC), and carbon storage (C) in the humic fractions. Total carbon contents increased with the increasing adoption of time of SPD, especially from NT6 to NT22. Humin fraction predominance was observed, with movement of HA and FA in the 0.0-0.4 m soil depth. The oxidizable C fractions showed equilibrium in the distribution of C contents, with higher levels in the more labile fractions, at surface. The cultivation with succession of crops contributes to the increase in labile fractions, but not to the increase of the more recalcitrant fractions of C.

Com o objetivo de avaliar o parcelamento de doses de nitrogênio (N), aplicadas na semeadura e em cobertura do milho, com e sem rotação de culturas, em semeadura direta, foi realizado um experimento com seis doses de N na semeadura (0, 20, 30, 40, 50 e 60 kg ha-1), combinadas com três doses em cobertura (40, 70, 100 kg ha-1) e dois sistemas de manejo: após cinco cultivos de milho e com rotação de culturas (milho+soja+aveia+soja+milho), em delineamento de blocos casualizados, com quatro repetições. O sistema de rotação de culturas proporcionou incremento de aproximadamente 7%, no rendimento de grãos, em relação ao da área sem rotação. O parcelamento da adubação nitrogenada, com doses acima de 39 e 54 kg ha-1, na semeadura, com 70 e 40 kg ha-1, em cobertura, respectivamente, resultou em produtividade superior à obtida com aplicação de 100 kg ha-1, em cobertura. O rendimento de grãos foi maior com o parcelamento da dose de 50 e 70 kg ha-1 de N, na semeadura e cobertura, em comparação com o obtido com o parcelamento de 20 e 100 kg ha-1, na semeadura e cobertura, respectivamente. A dose de 70 kg ha-1 de N em cobertura apresentou maior produtividade de grãos com menor custo, em comparação com os rendimentos e custos verificados em relação às doses de 40 e 100 kg ha-1.

The objective of this study was to evaluate split nitrogen (N) fertilization of maize applied in band at sowing and top dressing with and without crop rotation, under no-till. The experiment was conducted with six N rates at sowing (0, 20, 30, 40, 50 and 60 kg ha-1) combined with three rates in top dressing (40, 70, 100 kg ha-1) and two management systems: after five cropping sequences of maize and crop rotation (maize + soybean + oat + soybean + corn) in a randomized block design with four replications. The crop rotation system increased yield in approximately 7% in relation to the area without rotation. The split of nitrogen fertilization, in rates above 39 and 54 kg ha-1 at sowing and 70 and 40 kg ha-1 in top dressing, resulted in yield higher than that obtained with the application of 100 kg ha-1 in top dressing. Grain yield was higher with the rates 50 and 70 kg ha-1 of N compared with that obtained with 20 and 100 kg ha-1 at sowing and top dressing, respectively. The rate 70 kg ha-1 of N resulted in the highest yield at the lowest cost compared with the revenues and costs incurred with the rates 40 and 100 kg ha-1.

Dentre os solos existentes no Mato Grosso do Sul, destacam-se no Bioma Pantanal, os Espodossolos. Apesar de serem verificados em extensões consideráveis, poucos estudos com objetivo de caracterização e classificação desses solos foram realizados. Objetivou-se caracterizar e classificar solos de três feições fisiográficas da bacia do rio Taquari: baía e campos de inundação. Foram abertas duas trincheiras na área de baía (P1 e P2) e duas na de campos de inundação (P3 e P4). A terceira feição (salinas) foi amostrada para estudos posteriores, por apresentar altos teores de sódio. Nos solos estudados, nas duas áreas houve predomínio da fração areia, com textura variando de areia a franco-arenosa, sendo o principal constituinte o quartzo. Na área de baía o horizonte superficial (P1) apresentou teor de carbono orgânico (CO) maior que 80 g kg-1, sendo diagnosticado como H hístico. Para os demais perfis, os horizontes superficiais apresentaram baixos teores de CO, o que, em associação com outros atributos, fez com que eles fossem diagnosticados como A moderado. Nos solos da área de baía (P1 e P2) os valores de pH variaram de 5,0 a 7,5, associados à dominância dos íons Ca2+ e Mg2+, com saturação por bases, em alguns horizontes, maior que 50 %. Na área de campos de inundação, os solos (P3 e P4) mostraram valores de pH variando de 4,9 a 5,9, elevados valores de H+ nos horizontes superficiais (0,8 a 10,5 cmol c kg-1), valores de Ca2+ + Mg2+ variando de 0,4 a 0,8 cmol c kg-1 e saturação por bases maior que 50 %. Nos solos da área de baía (P1 e P2) ocorreu acúmulo de Fe, extraído por ditionito (Fed), e CO no horizonte espódico; e nos solos de campos de inundação (P3 e P4) houve acúmulo somente de Fed (nos horizontes subsuperficiais). De acordo com critérios adotados pelo Sistema Brasileiro de Classificação de Solos (SiBCS), em nível de subgrupo os solos foram classificados como: P1: Espodossolo Ferri-humilúvico hidromórfico organossólico, P2: Espodossolo Ferri-humilúvico órtico típico, P3: Espodossolo Ferrilúvico hidromórfico típico e P4: Espodossolo Ferrilúvico órtico espessarênico.

Among the soils in the Mato Grosso do Sul, stand out in the Pantanal biome, the Spodosols. Despite being recorded in considerable extensions, few studies aiming to characterize and classify these soils were performed. The purpose of this study was to characterize and classify soils in three areas of two physiographic types in the Taquari river basin: bay and flooded fields. Two trenches were opened in the bay area (P1 and P2) and two in the flooded field (P3 and P4). The third area (saline) with high sodium levels was sampled for further studies. In the soils in both areas the sand fraction was predominant and the texture from sand to sandy loam, with the main constituent quartz. In the bay area, the soil organic carbon in the surface layer (P1) was (OC) > 80 g kg-1, being diagnosed as Histic epipedon. In the other profiles the surface horizons had low OC levels which, associated with other properties, classified them as Ochric epipedons. In the soils of the bay area (P1 and P2), the pH ranged from 5.0 to 7.5, associated with dominance of Ca2+ and Mg2+, with base saturation above 50 % in some horizons. In the flooded fields (P3 and P4) the soil pH ranged from 4.9 to 5.9, H+ contents were high in the surface horizons (0.8-10.5 cmol c kg-1 ), Ca2+ and Mg² contents ranged from 0.4 to 0.8 cmol c kg-1 and base saturation was < 50 %. In the soils of the bay area (P1 and P2) iron was accumulated (extracted by dithionite - Fed) and OC in the spodic horizon; in the P3 and P4 soils only Fed was accumulated (in the subsurface layers). According to the criteria adopted by the Brazilian System of Soil Classification (SiBCS) at the subgroup level, the soils were classified as: P1: Organic Hydromorphic Ferrohumiluvic Spodosol. P2: Typical Orthic Ferrohumiluvic Spodosol. P3: Typical Hydromorphic Ferroluvic Spodosol. P4: Arenic Orthic Ferroluvic Spodosol.

O objetivo deste trabalho foi avaliar mudanças nos atributos químicos, no estoque de carbono e no índice de manejo de C de um Latossolo Vermelho argiloso, sob diferentes sistemas de manejo. Avaliou-se o solo sob sistemas de manejo com diferentes históricos de uso, sob as seguintes coberturas: Zea mays, Urochloa decumbens e Panicum maximum cv. Tanzania. Como testemunha, avaliou-se área sob vegetação de cerrado. Foram coletadas amostras compostas das camadas de solo de 0-5, 5-10 e 10-20 cm. Os teores de fósforo diminuíram com a profundidade, e os maiores valores foram observados na área com P. maximum. Na área com milho, observaram-se maiores valores de K+, Ca++, Mg++, CTC, e de soma e saturação por bases. O teor de C orgânico total do solo (COT) foi maior sob cerrado e menor sob cobertura com P. maximum, à profundidade de 5-10 cm. Os maiores estoques de COT, carbono nas frações particuladas (C-MOP) e nas frações associadas à fase mineral do solo ocorreram na área com U. decumbens, o que promoveu maiores índices de labilidade e de manejo de C, similares aos da vegetação de cerrado. Em todas as coberturas, a labilidade da matéria orgânica do solo diminuiu com o aumento da profundidade. A fração C-MOP apresenta maior sensibilidade às alterações de manejo e relaciona-se ao COT.

The objective of this work was to evaluate changes in the soil chemical attributes, carbon stock and in the C management index of a clayed Oxisol under different management systems. The soil under management systems with different historical usage was evaluated under the following covers: Zea mays, Urochloa decumbens, Panicum maximum cv. Tanzania. A cerrado area was used as check. Four composite samples were collected at 0-5, 5-10 and 10-20 cm soil depths. The phosphorus contents decreased with depth, and the higher values were observed in the area with P. maximum. In the area with Z. mays, higher values for K+, Ca++, Mg++, CEC, and base sum and saturation were observed. The total organic C content (TOC) was higher under cerrado vegetation cover, and smaller under P. maximum at 5-10 cm soil depth. The higher stocks of TOC, and of carbon in particulate fractions (C-POM) and in fractions associate to the soil mineral phase occurred in the area with U. decumbens, which promoted higher values for lability and C management indexes, similar to those for cerrado vegetation. In all coverings, the organic soil matter lability decreased with depth. The C-POM fraction had higher sensibility to variation in management practices, and is related to TOC.

O objetivo desse estudo foi avaliar diferentes métodos de secagem de folhas para três diferentes frutíferas (maracujá, pêssego e abacate), com relação à determinação da matéria seca e os teores foliares de macronutrientes. Foram coletadas amostras de folhas recém expandida de três culturas, do pomar da fazenda de ensino e pesquisa da FCAV-UNESP, câmpus de Jaboticabal, no mês de janeiro de 2010, coletando-se para cada cultura 12 amostras com 25 folhas cada. Os tratamentos constituíram-se por dois métodos de secagem, estufa de circulação de ar forçada regulada a uma temperatura de 70°C e o forno microondas (FMO). Avaliou-se a massa da matéria seca e os teores foliares de macronutrientes. Os resultados sugerem que os dois métodos de secagem testados se assemelham na determinação de matéria seca e nos teores foliares de macronutrientes para as culturas análisadas, exceto os teores de cálcio na cultura do pêssego.

The objective of this study was to evaluate different methods of drying of leaves for three different fruit (passion fruit, peach and avocado), with respect to the determination of dry matter and foliar nutrients. Samples were collected from recently expanded leaves of three crops orchard Farm education and research FCAV-UNESP, Jaboticabal campus, in January 2010, by collecting 12 samples for each culture with 25 leaves. The treatments consisted of two drying methods, greenhouse circulation of air regulated to a temperature of 70°C and FMO. We evaluated the mass of dry matter and foliar nutrients. The results suggest that the two drying methods tested did not interfere in the determination of dry matter and foliar nutrients to crops analyzed, except the calcium levels in peach.