ABSTRACT Phosphorus (P) is a limiting nutrient for coffee seedlings. To meet this requirement, coffee growers usually apply di-ammonium phosphate (DAP), which is highly sensitive to local price fluctuations. The use of arbuscular mycorrhizal fungi (AMF) and phosphate-solubilizing fungi (PSF) has been recommended, but the results derived from their application are inconsistent and uncertain, depending on soil fertility status. The response of AMF and PSF application in the plant growth of coffee seedlings during the nursery stage was evaluated in four non-sterile soils, which represent the most abundant type of soils in the coffee regions of Colombia: Eutropept, Dystropept, Fulvudand, and Ultisol. The treatments included a commercial AMF inoculum, PSF-Phlebia subserialis-CH4, and a consortium of AMF+PSF, at four P levels (0, 0.5, 1, and 2 g.plant-1 P2O5) using DAP fertilizer. Shoot dry weight (SDW) was affected by P applications in Fulvudand. In the other soils, a P-response occurred with 0.5 g.plant-1 , whereas 1 and 2 g.plant-1 of P2O5 caused a significant reduction in SDW. AMF increased SDW by 40% in Eutropept. The negative effect of higher P amounts was mitigated (> 70%) through PSF and AMF+PSF in Ultisol and Eutropept, respectively. In plants in which microorganisms increased SDW, the P concentration was 0.17 to 0.22%. The plant growth promotion of coffee seedlings during the nursery stage with AMF and/or PSF applications varied according to soil type and P amounts applied.

Abstract Introduction.Soybean establishes a symbiosis with Bradyrhizobium japonicum that allows it to fix atmospheric N. Coinoculation with other plant growth-promoting microorganisms can increase Biological Nitrogen Fixation (BNF) and plant growth. Objective. Determine if inoculation with P-solubilizing fungi (SP), Aspergillus flavus (S1) and Trichoderma longibrachiatum (S2), affects growth and BNF variables in soybeans. Materials and methods. In the greenhouse on an Andisol and an Ultisol, growth variables and BNF were evaluated in soybeans inoculated with B. japonicum and 2 SPs. Five treatments were evaluated: an absolute control (T), addition of phosphate rock (RF), addition of RF and inoculation with B. japonicum (BRF) and the addition of RF, B. japonicum and the 2 SPs independently (BRFS1 and BRFS2). An unrestricted randomized design with 4 repetitions was established and the data was analyzed according to normality, either with ANDEVA and DGC at 5% or Kruskal Wallis at 5%. Results. The responses obtained showed a positive effect on the evaluated variables when soybeans were inoculated with SP in addition with B. japonicum. The effect was a trend in Andisol, for the variables aerial fresh weight and number of nodules and their dry weight, while for Ultisol significance was found for these same variables, as well as for aerial dry weight, leaf area and N content and foliar P, with the greatest effect in BRFS2. In absolute terms, the highest P content in the soil microbial biomass and the highest SP population was found in the treatment with the presence of S2. The populations of N Fixers (NF) in the soil were higher for T and RF that did not have inoculation with B. japonicum. Conclusion. Inoculation with SP fungi can positively affect BNF, foliar N and P amounts as well as soybean plant growth.

Resumen Introducción. La soya establece una simbiosis con Bradyrhizobium japonicum para fijar N atmosférico. La coinoculación con otros microorganismos promotores del crecimiento (MPC) puede incrementar la Fijación Biológica de Nitrógeno (FBN) y el crecimiento de las plantas. Objetivo. Determinar si la inoculación con los hongos solubilizadores de P (SP), Aspergillus flavus (S1) y Trichoderma longibrachiatum (S2), afecta variables de crecimiento y de FBN en soya. Materiales y métodos. En un Andisol y un Ultisol en invernadero, se evaluaron variables de crecimiento y FBN en soya inoculada con B. japonicum y 2 SP. Se evaluaron 5 tratamientos: un testigo absoluto (T), adición de roca fosfórica (RF), adición de RF e inoculación con B. japonicum (BRF) y la adición de RF, B. japonicum y los 2 SP de manera independiente (BRFS1 y BRFS2). Se estableció un diseño irrestricto al azar con 4 repeticiones y los datos se analizaron según la normalidad, con ANDEVA y DGC al 5% o Kruskal Wallis al 5%. Resultados. Se obtuvo un efecto positivo sobre las variables evaluadas, cuando la soya se inoculó con los SP además de B. japonicum. El efecto fue tendencia en el Andisol, para las variables peso fresco aéreo y número de nódulos y su peso seco, mientras que para el Ultisol se encontró significancia para estas mismas variables, así como para el peso seco aéreo, área foliar y contenido de N y P foliar, el efecto fue mayor en BRFS2. En términos absolutos el mayor contenido de P en la biomasa microbiana del suelo y la mayor población de SP se encontró en el tratamiento con la presencia de S2. Las poblaciones de Fijadores de N fueron mayores para T y RF. Conclusión. La inoculación con hongos SP puede afectar positivamente la FBN, las cantidades de N y P foliar así como el crecimiento de las plantas de soya.

ABSTRACT. Sunflower growth is adversely impacted by both excess and insufficient water. Research on root growth in this crop under water stress conditions remains limited and does not fully elucidate the plant's response to varying soil and climatic conditions. This study aimed to determine root growth, depth, and distribution of sunflower plants under different water stress conditions, such as deficit or excess, in two soil classes and sown during two distinct periods. Experiments were conducted after sowing at the beginning of September (first crop season) and at the beginning of January (second crop season) in an Ultisol (Santa Maria, Rio Grande do Sul State, Brazil) and an Oxisol (Panambi, Rio Grande do Sul State, Brazil). Water condition treatments applied from stage V6 included control, water deficit, and water excess. Roots were collected using an auger drill during the first crop season. The variables analyzed comprised root length density and accumulated root within the soil profile. During the second crop season, sunflower roots were visually assessed in the soil profile after trench excavation. Root system depth and root dry mass were evaluated during both sowing periods. Results indicated that sunflower root penetration is deeper in Ultisol than in Oxisol. Water deficit promotes root depth, while water excess promotes root growth near the surface. Sowing during the first crop season results in deeper root penetration and higher root dry mass production compared to the second crop season. ABSTRACT plant s periods Santa Maria State Brazil Panambi, Panambi (Panambi Brazil. . V control excavation surface

RESUMEN El objetivo de este trabajo fue evaluar la producción de semillas y la capacidad de oferta forrajera de calidad del Kumanda yvyra’i (Cajanus cajan L.) sometido a diferentes dosis de fertilización orgánica. Fue utilizado el diseño de bloques completos al azar (DBCA) con arreglo de parcelas subdividas con cuatro tratamientos y tres repeticiones. Los tratamientos consistieron en un testigo (0 kg ha-1), y tres dosis crecientes de gallinaza (5.000, 10.000 y 15.000 kg ha-1). Las variables evaluadas fueron altura de plantas (AP), masa verde (MV), masa seca (MS), cantidad de plantas (CP), número de vainas (NV), masa de vaina fresca y seco (PVf y PVs), producción de semillas (PS). No se observaron diferencias significativas entre las variables evaluadas, exceptuando para MV y MS, donde al nivel de 5.000 kg de gallinaza (T1), se observó la mayor producción (34.533,3 kg.MV ha-1 y 17.642,1 kg.MS ha-1) diferenciándose de los demás tratamientos (promedio: 24.925 kg.MV ha-1 y 13.890,6 kg.MS ha-1) y el testigo (24.050,0 kg.MV ha-1 y 13.134,5 kg.MS ha-1). En cuanto las demás variables; los promedios observados fueron los siguientes, AP: 2,12 m (S) y 2,10 m (F), CP: 19,4 pl m-2 (S) y 22,3 pl/m2 (F), NV: 800,9 vainas/m2 y 43,4 vainas/pl, PVf: 3946,7 kg ha-1 y PVs: 3694,4 kg ha-1, PS: 972.222,2 semillas ha-1. La fertilización orgánica no afecta significativamente las variables de altura y cantidad de plantas. La dosis de 5.000 kg ha-1 incrementó la materia verde y seca, en la producción semillera no se observaron diferencias estadísticas significativas en las variables evaluadas.

ABSTRACT This study was carried out to evaluate the seed production and the quality forage supply capacity by the pigeon pea (Cajanus cajan L.) subjected to different doses of organic fertilization. The design used was randomized complete blocks (RCBD) with arrangement of subdivided plots with four treatments and three repetitions. The treatments consisted of a control (0 kg ha-1), and three increasing doses of chicken manure (5.000, 10.000 and 15.000 kg ha-1). The variables evaluated were plant height (PH), green mass (GM), dry mass (DM), number of plants (NP), number of pods (NP), weight of fresh and dry pods (WPf and WPs), seed production (SP), nodules (NO). No significant differences were observed between the variables evaluated, except for GM and DM, where at the level of 5.000 kg of poultry manure (T1), the highest production was observed (34.533,3 kg.GM ha-1 and 17.642,1 kg.DM ha-1) differing from the other treatments (24,925 kg.GM ha-1 and 13,890.6 kg.DM ha-1) and the control (24,050.0 kg.GM ha-1 and 13,134.5 kg.DM ha-1). As for the other variables, the observed averages were for PH: 2,12 m (S) and 2,10 m (F), NPl: 19,4 pl m-2 (S) and 22,3 pl m-2 (F), NP: 800,9 pods m-2 and 43,4 pods/pl, WPf: 3946,7 kg ha-1 y WPs: 3594,4 kg ha-1, SP: 972.222,2 seeds/ha. No noteworthy nodulations were presented.

ABSTRACT Soil management systems, including tillage and green manuring, are important for the control of nematodes and for the sustainable production. The objective was to select, through multivariate analysis, sustainable agroecosystems for yellow melon cultivated under irrigated conditions in the Brazilian semi-arid region. The long-term experiment is set up in Argissolo Vermelho- Amarelo (Ultisol) with six multifunctional agroecosystems, composed of the combination of three mixtures of cover crops (1 - 75% legumes + 25% grasses and oilseeds; 2 - 25% legumes + 75% grasses and oilseeds and 3 - spontaneous vegetation) and two types of soil management (no tillage-NT and tillage-T). The purpose was to evaluate the nutritional status of plants, soil fertility, nematode population in roots and soil, and the yield. Data were analyzed with multivariate techniques, allowing the grouping of the agroecosystems based on their similarities and complexity of functions. The incorporation of plant residues to the soil reduces nematode population, but their maintenance on the surface allows the improvement of fertility and yield, even under larger nematode populations. The agroecosystems that associate the nonincorporation of residues from cover crops with larger species diversity in composition constitute the most complex model, allowing different environmental functionalities. Thus, it is recommended not to incorporate the plant residues, planting the melon seedlings directly in the straw. However, considering that the results obtained with the non-incorporation of spontaneous vegetation were similar to those obtained with the incorporation of commercial cover crops, it is concluded that this practice is also viable and adapted to the semi-arid conditions.

RESUMO Sistemas de manejo de solos, incluindo revolvimento e adubação verde, são importantes para o controle de nematoides e para a produção sustentável. Objetivou-se selecionar, por meio da análise multivariada, agroecossistemas sustentáveis para cultivo irrigado de melão amarelo no Semiárido brasileiro. As avaliações ocorreram num experimento de longa duração, com seis agroecossistemas multifuncionais, compostos pela combinação de três misturas de plantas de cobertura (1 - 75% leguminosas + 25% gramíneas e oleaginosas; 2 - 25% leguminosas + 75% gramíneas e oleaginosas e 3 - vegetação espontânea) e dois tipos de manejo do solo (sem e com revolvimento). Avaliaram-se o estado nutricional das plantas, a fertilidade do solo, as populações de nematoides nas raízes e no solo e a produtividade da cultura. Os dados foram submetidos às técnicas de análises multivariadas, permitindo agrupar os agroecossistemas por semelhanças e complexidade das suas funções. A incorporação dos resíduos vegetais ao solo reduz a população de nematoides, mas sua manutenção na superfície permite melhorar a fertilidade e alcançar boas produtividades, mesmo sob maior população de nematoides. Os agroecossistemas que associam o não revolvimento dos resíduos vegetais das plantas de cobertura com maior diversidade de espécies na composição é o modelo considerado mais complexo, permitindo diferentes funcionalidades ambientais. Assim, recomenda-se não incorporar os resíduos vegetais, transplantando as mudas de meloeiro diretamente sobre a palhada. No entanto, considerando que os resultados obtidos com a não incorporação da vegetação espontânea foram semelhantes à incorporação das plantas de cobertura comerciais, conclui-se que esta prática também é viável e adaptada às condições semiáridas.

RESUMO O uso de doses elevadas de vinhaça no cultivo da cana-de-açúcar modifica os atributos químicos do solo. Objetivou-se com o presente trabalho avaliar o efeito da aplicação de doses elevadas de vinhaça sobre características químicas de um Argissolo Amarelo cultivado com cana-de-açúcar. Os tratamentos consistiram na aplicação de doses equivalentes a 0 (D0), 150 (D150), 300 (D300), 600 (D600) e 1200 (D1200) m3 ha-1 de vinhaça e mais uma testemunha. O delineamento experimental adotado foi inteiramente casualizado, com seis tratamentos e seis repetições. Avaliou-se a concentração de potássio (K), cálcio (Ca), magnésio (Mg) e sódio (Na) trocável, matéria orgânica, Capacidade de Troca Catiônica, Razão de Adsorção de Sódio, Porcentagem de Sódio Trocável, Condutividade Elétrica e pH aos 90, 120, 150 e 210 dias após o plantio (DAP), além da respiração basal microbiana aos 210 dias. O experimento foi conduzido em vasos com capacidade de 100 L. O pH do solo aumentou com a aplicação da vinhaça dentro da faixa considerada como adequada para a cana-de-açúcar, variando de 6,2 a 6,4. O K e Na apresentaram maiores concentrações em D600 e D1200; as maiores disponibilidades de K e Na no solo ocorreram, respectivamente, aos 120 e 150 DAP, indicando competição entre os elementos pelos sítios de troca. O teor de matéria orgânica foi proporcionalmente elevado conforme a dose de vinhaça aplicada. As doses D600 e D1200 aumentam a concentração de Na no solo, com maior magnitude na profundidade 0 – 0,20 m. canadeaçúcar cana açúcar Objetivouse Objetivou se canadeaçúcar. açúcar. D0, D0 D , (D0) 15 D150, D150 (D150) 30 D300, D300 (D300) 60 (D600 (D1200 m ha1 ha 1 ha- testemunha casualizado repetições Avaliouse Avaliou K, (K) Ca, Ca (Ca) Mg (Mg (Na trocável Catiônica Trocável 90 21 DAP (DAP) 10 L canadeaçúcar, açúcar, 62 6 2 6, 64 4 6,4 D60 ocorreram respectivamente 12 troca aplicada D120 020 20 0,2 (D0 D15 (D150 3 D30 (D300 (D60 (D120 (K (Ca 9 (DAP D6 D12 02 0, (D D1 (D15 D3 (D30 (D6 (D12 (D1 (D3

ABSTRACT The use of high doses of vinasse in sugarcane crop can cause modifications in the chemical characteristics of the soil. The aim of this study was to evaluate the effect of the application of high doses of vinasse on the chemical characteristics of an Ultisol cultivated with sugarcane for 210 days. The treatments used were doses equivalent to 0 (D0), 150 (D150), 300 (D300), 600 (D600) and 1200 (D1200) m3 ha-1 of vinasse plus a control treatment with mineral fertilization. The experimental design was completely randomized with six treatments and six repetitions. Exchangeable potassium (K), calcium (Ca), magnesium (Mg) and sodium (Na) contents, organic matter, cation exchange capacity, sodium adsorption ratio, exchangeable sodium percentage, electrical conductivity and pH were analyzed at 90, 120, 150 and 210 days after planting (DAP), in addition to microbial basal respiration at 210 days at depths of 0-0.20 and 0.20-0.40 m. Soil pH increased with the use of vinasse within the proper range for sugarcane, varying from 6.2 to 6.4. The highest K and Na contents were found at D600 and D1200; the highest K and Na availability occurred at 120 DAP and 150 DAP, respectively, indicating competition between these nutrients for exchange sites. Organic matter content was proportionally high according to the vinasse dose applied. D600 and D1200 doses increased Na content in the soil, with greater magnitude at the 0-0.20 m depth. soil 21 D0, D0 D , (D0) 15 D150, D150 (D150) 30 D300, D300 (D300) 60 (D600 (D1200 ha1 ha 1 ha- fertilization repetitions K, (K) Ca, Ca (Ca) Mg (Mg (Na capacity ratio percentage 90 (DAP) 00.20 0020 0.20 20 0-0.2 0.200.40 020040 0.40 40 0.20-0.4 62 6 2 6. 64 4 6.4 D60 12 respectively sites applied D120 depth (D0 D15 (D150 3 D30 (D300 (D60 (D120 (K (Ca 9 (DAP 00 00.2 002 020 0.2 0-0. 200 0.200.4 02004 040 0.4 0.20-0. D6 D12 (D D1 (D15 D3 (D30 (D6 (D12 00. 02 0. 0-0 0.200. 0200 04 0.20-0 (D1 (D3 0- 0.200 0.20-

RESUMO A qualidade do solo, medida por meio de seus atributos químicos, físicos e microbiológicos, muda em função das interações antrópicas e torna-se uma importante ferramenta para avaliar a qualidade ambiental. O objetivo deste estudo foi determinar e avaliar o Índice de Qualidade de um Argissolo em parcelas de longo prazo (17 anos) sob diferentes sistemas de manejo nos Tabuleiros Costeiros do Estado de Sergipe, Nordeste do Brasil. Os principais efeitos foram plantio convencional (CC), cultivo minimo (CM) e plantio direto (MT) distribuídos em faixas cultivadas com milho como cultura principal. Os tratamentos fracionados foram distribuídos aleatoriamente e cultivados com feijão-caupi (Vigna unguiculata), crotalária (Crotalaria juncea), feijão guandu (Cajanus cajan) e milheto (Pennisetum glaucum). Um solo florestal foi utilizado como referência. O Índice de Qualidade do Solo (IQS) para a camada de 0-0,10 m foi calculado pelo método aditivo. Houve mudanças nas propriedades do solo entre os diferentes sistemas de manejo, e entre o solo do experimento e a área de referência. O maior IQS foi obtido da área de floresta (67,1) seguido do tratamento PD (65,5), CM (65,1) e tratamento CC (61,0). O menor IQS foi observado no tratamento CC previamente cultivado com feijão guandu (56,5). Dentre as funções avaliadas do solo, a manutenção da homeostase teve a maior influência no IQS. A maior acidez do solo florestal ajuda a explicar a origem das limitações do solo na área cultivada que ocupa o mesmo tipo de solo, exigindo a adoção de manejos conservacionistas. químicos microbiológicos tornase torna se ambiental 17 (1 anos Sergipe Brasil CC, , (CC) (CM MT (MT principal feijãocaupi caupi Vigna unguiculata, unguiculata unguiculata) Crotalaria juncea, juncea juncea) Cajanus cajan Pennisetum glaucum. glaucum . glaucum) referência (IQS 00,10 0010 0 0,10 10 0-0,1 aditivo 67,1 671 67 1 (67,1 65,5, 655 65,5 65 5 (65,5) 65,1 651 (65,1 61,0. 610 61,0 61 (61,0) 56,5. 565 56,5 56 (56,5) conservacionistas ( (CC 00 00,1 001 010 0,1 0-0, 67, 6 (67, 65, (65,5 (65, 61, (61,0 56, (56,5 00, 01 0, 0-0 (67 (65 (61, (56, 0- (6 (61 (56 (5

ABSTRACT Soil quality, measured through its chemical, physical and microbiological attributes, changes as a result of anthropic sensations and becomes an important tool to assess environmental quality. The objective of this study was to determine and evaluate the Quality Index of an Ultisol in a long-term (17-yr) plots under different management systems in the Coastal Tablelands of Sergipe State, in Northeastern, Brazil. Main effects were conventional tillage (CT), no-tillage (NT), and minimum tillage (MT) distributed cultivated strips with corn as the main crop. Split-range treatments were randomly distributed and cultivated with cowpea beans (Vigna unguiculata), sunn hemp (Crotalaria juncea), pigeon pea (Cajanus cajan), and millet (Pennisetum glaucum). A forest soil was used as reference, compared to the soil samples of the cultivated area. The Soil Quality Index (SQI) for the 0-0.10 m layer was calculated by the additive method. There were changes in soil properties between the different management systems, and between the experimental soil and the reference area. The highest SQI was obtained from the forest area (67.1) followed by the NT treatment (65.5), MT (65.1) and CT treatment (61.0). The lowest SQI was observed in the CT treatment previously cultivated with pigeon pea (56.5). Among the evaluated soil functions, maintenance of homeostasis had the greatest influence on the SQI. The higher acidity of the forest soil helps to explain the origin of the limitations of the soil in the cultivated area that occupies the same type of soil, tolerated by the adoption of conservationist managements. quality chemical attributes longterm long term 17yr yr 17 (17-yr State Northeastern Brazil CT, , (CT) notillage no NT, (NT) (MT crop Splitrange Split range Vigna unguiculata, unguiculata unguiculata) Crotalaria juncea, juncea juncea) Cajanus cajan, cajan cajan) Pennisetum glaucum. glaucum . glaucum) (SQI 00.10 0010 0 0.10 10 0-0.1 method 67.1 671 67 1 (67.1 65.5, 655 65.5 65 5 (65.5) 65.1 651 (65.1 61.0. 610 61.0 61 (61.0) 56.5. 565 56.5 56 (56.5) functions managements (CT (NT 00 00.1 001 010 0.1 0-0. 67. 6 (67. 65. (65.5 (65. 61. (61.0 56. (56.5 00. 01 0. 0-0 (67 (65 (61. (56. 0- (6 (61 (56 ( (5

Abstract The objective of this work was to evaluate the application of silicate ultramafic alkaline rock, with different granulometry, as an alternative potassium source on the increase of soil fertility and on the nutritional status and biomass yield of the alfalfa and centrosema crops. The used soil was a Typic Ultisol with 27.4 mg dm-3 K and 733 g kg-1 clay. The experimental design was completely randomized, in a 4 × 2 + 1 factorial arrangement. The treatments consisted of two granulometries (<0.3 and 0.3-2.0 mm) of alkaline ultramafic rock (4.0% K2O), four K rates (0, 100, 150, and 300 mg kg-1), and an additional treatment with the application of 150 mg kg-1 K in the form of KCl (58% K2O). Both legumes were grown in a greenhouse and subjected to five successive harvests. In comparison with KCl, the application of silicate rock has the potential to increase K uptake and root and shoot dry weight yield in alfalfa and centrosema. Granulometry does not affect rock use efficiency, and alfalfa presents a better K efficiency recovery in the soil after successive harvests compared with centrosema; the inverse is observed for K use and K uptake efficiencies.

Resumo O objetivo deste trabalho foi avaliar a aplicação de rocha silicática ultramáfica alcalina com diferentes granulometrias, como fonte alternativa de potássio no aumento da fertilidade do solo e no estado nutricional e na produção de biomassa das cultura de alfafa e centrosema. O solo utilizado foi um Argissolo Amarelo distrófico com 27,4 mg dm-3 de K e 733 g kg-1 de argila. O delineamento experimental foi inteiramente casualizado, em arranjo fatorial 4 × 2 + 1. Os tratamentos consistiram em duas granulometrias (< 0,3 e 0,3-2,0 mm) da rocha ultramáfica alcalina (4,0% de K2O), na aplicação de quatro doses de K (0, 100, 150 e 300 mg kg-1) e de um tratamento adicional com a aplicação de 150 mg kg-1 de K na forma de KCl (58% de K2O). Ambas as leguminosas foram cultivadas em casa de vegetação e submetidas a cinco cortes sucessivos. Em comparação ao KCl, a aplicação da rocha silicática apresenta potencial para aumentar a absorção de K e a produção de matéria seca de raízes e da parte aérea da alfafa e da centrosema. A granulometria não altera a eficiência de uso da rocha, e a alfafa apresenta maior eficiência de recuperação de K do solo após cortes sucessivos em comparação à centrosema; o inverso é observado para eficiências de uso e absorção de K.

RESUMEN El objetivo de este estudio fue investigar las alteraciones físicas y químicas de los suelos ácidos asociadas a la aplicación de vinaza en condiciones de laboratorio. Los efectos beneficiosos de cinco dosis de vinaza (sin vinaza [0, solamente agua], 50, 100, 150 y 200 m3/ha), fueron estudiadas en el mejoramiento de las propiedades físicas y químicas de tres suelos ácidos: Oxisol (SO), Ultisol (SU) y Argisol (SA), después de 30 días de incubación. Las muestras de suelos fueron recolectadas en la capa de 0-20 cm de profundidad para la determinación de propiedades físicas y químicas como pH (CaCl2), acidez total (AT), acidez intercambiable (Al3+), cationes bases (K+, Ca2+ y Mg2+), suma de bases (SB), capacidad de intercambio catiónico (CIC), índice de saturación de las bases (V%), y saturación de potasio (K), calcio (Ca), magnesio (Mg) y aluminio (Al). Los resultados indicaron que la aplicación de vinaza mejoró las propiedades físicas y químicas de los suelos estudiados, porque se incrementaron tanto el pH como los cationes bases, la SB, la CIC, el V% y la saturación de K, Ca y Mg, y disminuyeron la AT, Al3+ y saturación de Al. Además, los efectos más importantes en el mejoramiento de las propiedades físicas y químicas de los suelos ácidos se observaron en la dosis de 200 m3/ha de vinaza. Los hallazgos de este estudio sugieren que la vinaza podría ser una estrategia efectiva de bajo costo como fuente alternativa para balancear la acidez del suelo y constituiría una opción apropiada para disminuir la contaminación ambiental.

ABSTRACT The objective of this study was to investigate the acidic soil physical and chemical alteration associated to vinasse application under laboratory conditions. The experiment was distributed in a factorial scheme (5 × 3), in a completely randomized design, with four replicates. The beneficial effects of five vinasse doses (without vinasse [0, only water], 50, 100, 150, and 200 m3/ha) in enhancing the physical and chemical properties of three acidic soils: Oxisol (SO), Ultisol (SU), and Argisol (SA) were studied after 30 days of incubation. Soil samples were collected in the 0-20 cm depth layer to determine physical and chemical properties such as pH (CaCl2), total acidity (AT), exchangeable acidity (Al3+), base cations (K+, Ca2+, and Mg2+), sums of bases (SB), cations exchange capacity (CIC), base saturation index (V%), and saturation of potassium (K), calcium (Ca), magnesium (Mg), and aluminum (Al). Results indicated that vinasse application enhanced the physical and chemical properties of the studied soils, since pH, base cations, SB, CIC, V%, and saturation of K, Ca, and Mg were increased, while AT, Al3+, and Al saturation were decreased. The most important effects in the improvement of physical and chemical properties of acidic soils were observed with a dose of 200 m3/ha of vinasse. The findings of this study suggest that vinasse could be a low-cost effective strategy as an alternative source for balancing soil acidity and would be an appropriate option for minimizing environmental pollution.

RESUMO Os solos leves possuem maior suscetibilidade ao processo de degradação e necessitam ser explorados de forma conservacionista, evitando assim sua rápida degradação. Objetivou-se com o estudo avaliar as propriedades físico-hídricas de um Argissolo sob plantio direto e integração lavoura-pecuária no Cerrado da região leste do estado do Maranhão. Os manejos avaliados foram uma área sob sistema de plantio direto há quatorze anos (soja/milheto) e três áreas com diferentes históricos de adoção do sistema de integração lavoura-pecuária (ILP) sob plantio direto (soja/milheto), sendo a diferença os tempos de entrada com ILP (2, 4 e 8 anos), além de uma área de cerrado nativo, considerado testemunha. A coleta do solo foi realizada em junho de 2018 nas profundidades de 0,00-0,10; 0,10-0,20; 0,20-0,30; 0,30-0,50 m. Foram coletadas amostras deformadas e indeformadas, para determinação das variáveis: densidade do solo, porosidade, resistência à penetração, curva de retenção e capacidade de água disponível. Os dados foram submetidos ao cálculo das médias e de intervalo de confiança (95 %). A área com histórico recente de integração lavoura-pecuária apresentou melhor densidade, porosidade, resistência a penetração e capacidade de armazenamento e água disponível. O plantio direto há quatorze anos apresenta alta resistência a penetração, menor porosidade e baixa capacidade de armazenamento de água. O sistema integrado (ILP) melhora a qualidade das propriedades físico - hídricas, sendo o sistema com maior capacidade de água disponível para as plantas.

ABSTRACT Light soils are more susceptible to degradation and need to be exploited in a conservational manner, thus avoiding rapid degradation. The objective of this study was to evaluate the physical-hydraulic properties of an Ultisol under no-tillage and crop-livestock integration in the Cerrado of eastern Maranhão state, Brazil. The evaluated managements were one area under no-tillage system for fourteen years (soybean/ millet) and three areas with different histories of adoption of the crop-livestock integration (CLI) system under no-tillage (soybean/millet), with the difference being: times of entry with CLI (2, 4 and 8 years), as well as a native Cerrado area, considered a control. Soil collection was carried out in June 2018 at depths of 0.00-0.10, 0.10-0.20, 0.20-0.30 and 0.30-0.50 m. Disturbed and undisturbed samples were collected to determine the following variables: bulk density, porosity, resistance to penetration, retention curve and available water capacity. Data were subjected to the calculation of means and confidence intervals (95%). The area with a recent history of crop-livestock integration showed better density, porosity, resistance to penetration, water storage capacity and available water. No-tillage for fourteen years leads to high resistance to penetration, less porosity and low water storage capacity. The integrated system (CLI) improves the quality of the physical- hydraulic properties and the values found are similar to those observed in an area under native vegetation.

RESUMO Considerando as perdas de fósforo (P) no solo pelo processo de adsorção e que o uso do biocarvão parece promissor do ponto de vista agrícola, objetivou-se com este estudo avaliar o processo de adsorção de P pelo solo Argissolo incubado com diferentes doses de biocarvão através de estudo cinético e isotérmico. O experimento foi realizado com biocarvão de cama de aviário pirolisado a 350 °C. O Argissolo foi incubado com doses crescentes de biocarvão, de 0,0 a 61,95 t ha-1. Após 60 dias, foram avaliadas a taxa de adsorção de fósforo, e cinética e isotermas de adsorção. Os resultados mostraram que o solo apresentou a maior capacidade de adsorção de fósforo (1,105 mg g-1). O biocarvão não foi um bom adsorvente de P; independente das doses aplicadas, liberou P para a solução de equilíbrio. O modelo de Langmuir foi o melhor para descrever a adsorção de P. A cinética de adsorção de P se ajustou bem ao modelo de pseudo-segunda ordem, mostrando que a adsorção é controlada quimicamente. Esses resultados sugerem que o biocarvão pode aumentar a disponibilidade de P no solo, limitando a adsorção, portanto, pode ser usado como fertilizante e/ou condicionador de solo.

ABSTRACT Considering the losses of phosphorus (P) in the soil by the adsorption process and that the use of biochar seems promising from the agricultural point of view, the aim of this research was to evaluate P adsorption by the Ultisol incubated with different biochar doses through kinetic and isothermal study. The experiment was carried out with poultry litter biochar pyrolyzed at 350 °C. Ultisol was incubated with increasing biochar doses, from 0.0 to 61.95 t ha-1. After 60 days, the phosphorus adsorption rate, kinetics and adsorption isotherms were evaluated. The results showed that the soil had the highest capacity to adsorb phosphorus (1.105 mg g-1). Biochar was not a good P adsorbent; regardless of the applied doses, it released P to the equilibration solution. Langmuir model was better at describing the adsorption of P. The pseudo-second order model fitted well to the adsorption kinetics of P, showing that the adsorption is chemically controlled. These results suggest that biochar can increase the availability of P, limiting adsorption; therefore, it could be used as a fertilizer and/or soil conditioner.

ABSTRACT The aim of this study was to evaluate the physical quality of the soils by evaluating the variation of soil penetration resistance, resulting from tillage with chiseling in the planting row and in total area, and the possible interferences of the managements in sugarcane yield. The study was carried out in southeastern Brazil, in areas under Oxisol and Ultisol, which are the two soils with the greatest representativeness of sugarcane cultivation in the country. The treatments consisted of soil tillage in total area and localized tillage in the sugarcane planting row, with 10 replicates. Undisturbed soil samples were collected in the 0-0.10, 0.10-0.20, and 0.20-0.40-m soil layers in sugarcane rows and interrows in both soil types for penetration resistance determination in laboratory. Samplings were carried out at three times, the first after soil tillage, the second after sugarcane planting, and the third six months after planting. Compared to the system with tillage in total area, localized tillage promoted higher values of soil penetration resistance in sugarcane interrows. However, this was not enough to reduce the crop yield. In the planting row, there are no differences between tillage types for soil penetration resistance. Localized soil tillage in sugarcane crop is a conservation and sustainable alternative that can replace soil tillage in total area, not interfering in the PR determined in the crop row and not altering the stem yield, regardless of the soil type.

RESUMO: Os sistemas integrados de produção agropecuária possuem potencial de incrementar a matéria orgânica, com reflexos nas concentrações de carbono e de nitrogênio no solo. O objetivo do trabalho foi avaliar estoques de carbono e nitrogênio e seus compartimentos em um Argissolo Amarelo Distrocoeso típico sob plantio direto e integração lavoura-pecuária no Leste maranhense. Os manejos avaliados foram: sistema de plantio direto em sucessão há 14 anos (soja/milheto), três áreas com diferentes históricos de sucessão com a adoção do sistema integração lavoura-pecuária (ILP), sendo dois, quatro e oito anos, além de uma área de Cerrado nativo. Foram coletadas amostras de solo nas profundidades de 0,00-0,10; 0,10-0,20; 0,20-0,30; 0,30-0,50 metros para análise de teores e estoques totais de carbono (C) e de seus compartimentos (físico e químico), nitrogênio (N) e da biomassa microbiana do solo e respiração basal. Os resultados revelam maior teor e estoque de C e N nas áreas com ILP. A substância húmica predominante foi a humina e maiores concentrações do carbono associado a minerais estiveram presentes na área sob ILP mais recente (dois e quatro anos). A adoção da ILP, mesmo que recente, proporciona incrementos imediatos nas concentrações de C e suas frações em função do emprego de forrageiras. O plantio direto há 14anos e ILP há oito anos são sistemas com maior índice de manejo do C, como, também, apresentam maior atividade biológica do solo, devido à maiores estabilidade destes sistemas.

ABSTRACT: Integrated agricultural production systems have the potential to increase organic matter content, which is reflected in the soil carbon (C) and nitrogen (N) concentrations. Here, we evaluated the C and N stocks and its compartments in a typical distro cohesive yellow Ultisol under the no-till (NT) and crop-livestock integration (CLI) systems, in eastern Maranhão. Five areas with different management strategies were evaluated, more specifically, one area was managed under the NT system in succession for 14 years (soybean/millet), three areas had different CLI system adoption histories (i.e., CLI was adopted 2, 4, or 8 years prior to sample collection); and finally, one area consisted of native Cerrado (savannah) vegetation. Soil samples were collected at depths of 0-0.10, 0.10-0.20, 0.20-0.30, and 0.30-0.50 m,to analyze the content and total stocks of carbon (C) and its compartments (physical and chemical), N content, soil microbial biomass, and basal respiration. Results revealed higher content and stock of C and N in areas with CLI. The principal humic substance reported was humin, and higher concentrations of C associated with minerals were present in areas under more recent CLI adoption (2 and 4 years). We demonstrated that the adoption of CLI, even if recent, leads to immediate increases in the concentrations of C and its fractions as a result of using forage crops. NT for 14 years and CLI for 8 years exhibited higher levels of C management and higher soil biological activity due to the greater stability of these systems.

RESUMO As substâncias húmicas (SH) têm se mostrado eficazes em incrementar a produtividade de hortaliças. O objetivo deste trabalho foi avaliar o efeito de bioestimulantes comerciais ricos em ácidos húmicos (AH) e fúlvicos (AF), obtidos de leonardita, na eficiência agronômica da cultura de alface e teor de nutrientes na planta. Foi realizado um experimento em casa-de-vegetação em vasos de 2,5 L com amostras de Argissolo, aos quais foram aplicados bioestimulantes comerciais ricos em AH e em AF, isoladamente e em combinação com o fertilizante mineral NPK. A aplicação dos bioestimulantes à base de SH associada à fertilização mineral na cultura da alface apresentou os maiores valores das variáveis estudadas: altura e diâmetro de plantas, número de folhas por planta e comprimento de raiz. A combinação do bioestimulante rico em AF e o fertilizante mineral aumentou a produção da alface em relação à aplicação isolada do fertilizante inorgânico. A aplicação combinada dos bioestimulantes ricos em AF e em AH com o fertilizante NPK influenciou a absorção de K e Fe pelas plantas, e seu acúmulo na parte aérea. Nossos resultados sugerem que as SH potencializam o efeito nutricional do fertilizante mineral, quando aplicadas conjuntamente.

ABSTRACT Humic substances (HS) have proved to be effective in improving the productivity of vegetable crops. We examined the effect of commercial biostimulants rich in humic (HA) and fulvic acids (FA) obtained from leonardite on agronomic efficiency and nutrient content in the leaves of lettuce (Lactuca sativa). A greenhouse experiment was carried out employing 2.5-L pots containing Ultisol samples that were supplied with commercial biostimulants rich in HA and FA, alone and in combination with NPK mineral fertilizer. The application of HS biostimulants associated to mineral fertilization to the lettuce plants provided the greatest values of the studied variables, namely: plant height and diameter, leaf number per plant and root length. The combination of FA biostimulants and mineral fertilization increased the lettuce productivity relative to the inorganic fertilizer alone. The combined application of rich biostimulants FA and HA with NPK fertilizes influenced K and Fe uptake by the plants, and their accumulation in the aerial portion. Our results suggest that HS products potentialize the nutritional effect of the mineral fertilizer, when applied in combination.

RESUMO Na plantação de cana-de-açúcar, o Imazapic tem sido usado em pré ou pós-emergência, isoladamente ou em combinação com outros herbicidas. Quando aplicado ao solo em pré-emergência, o Imazapic pode sofrer os processos de sorção, lixiviação e/ou degradação por efeitos físicos, químicos e biológicos, além de ser absorvido por plantas daninhas. O objetivo deste trabalho foi avaliar a interação e mobilidade do herbicida Imazapic no solo onde foram utilizadas colunas de solo com um Argissolo Amarelo distrófico (YUd) e um Latossolo Vermelho-Amarelo distrófico (RYOd) do Nordeste do Brasil. O maior potencial de adsorção do RYOd está associado ao maior teor de argila, maiores concentrações de Fed e Feo e pH ácido do solo. O modelo CDE - 2 de dois sítios de sorção representou adequadamente os dados experimentais das curvas de eluição do Imazapic para os solos RYOd e YUd. A partir dos coeficientes de partição Kd para RYOd e YUd, altos valores do índice GUS (5,94 e 7,04, respectivamente) foram calculados, confirmando o alto potencial de lixiviação da molécula Imazapic nesses solos.

ABSTRACT In the plantation of sugarcane, Imazapic has used pre- or post-emergence, alone or in combination with other herbicides. When applied to the soil in pre-emergence, Imazapic can undergo the sorption, leaching and/or degradation processes due to physical, chemical and biological effects, besides being absorbed by weeds. The objective of this work was to evaluate the interaction and mobility of the Imazapic herbicide in the soil where the soil columns with a dystrophic Yellow Ultisol (YUd) and a dystrophic Red-Yellow Oxisol (RYOd) from northeastern Brazil were used. The higher adsorption potential of the RYOd is associated with higher clay content, higher Fed and Feo concentrations, and soil acidic pH. The CDE – 2 sorption sites model adequately represented the experimental data from the Imazapic breakthrough curves to the RYOd and YUd soils. From the Kd partition coefficients for RYOd and YUd, high values of the GUS index (5.94 and 7.04, respectively) were calculated, confirming the high leaching potential of the Imazapic molecule in these soils.