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Sugarcane productivity is highly variable across space, and knowledge about the spatial distribution of soil physical attributes is important to guide management practices and evaluate the effects of agricultural operations on productivity. Thus, the objective of this study was to determine the best sampling density to represent the physical attributes of an Ultisol Typic Hapludult, to determine the spatial variability of these physical attributes, and to correlate them with sugarcane productivity. A sampling grid was delimited in a sugarcane crop in its first cycle, where 32 samples were collected that were spaced 7 m apart. The samples were collected undisturbed for soil density, total porosity, macroporosity and microporosity determination. In addition, disturbed samples were also collected to determine gravimetric water content. A penetrometer was used to evaluate the soil mechanical resistance. Sugarcane productivity was measured in the same sites. Descriptive statistics and geostatistical analysis were applied to evaluate data variability and correlation between sugarcane productivity and soil physical attributes. The physical attributes of soil: penetration resistance, moisture, total porosity, macroporosity, microporosity, soil density and sugarcane productivity showed spatial dependence, and fit to spherical and exponential mathematical models. Kriging maps identified homogeneous and heterogeneous regions, indicating that the geostatistical techniques were useful for geospatial characterization. The minimum sampling density to estimate sugarcane productivity was 14 samples per hectare and was dependent on penetration resistance and total soil porosity.

Geostatistical and multivariate techniques have been widely used to identify and characterize the soil spatial variability, as well as to detect possible relationships between soil properties and management. Besides that, these techniques provide information regarding the spatial and temporal structural changes of soils to support better decision-making processes and management practices. Although the Zona da Mata region is a reference for sugarcane production in the northeast of Brazil, only a few studies have been carried out to clarify the effects of different management on soil physical attributes by using geostatistical and multivariate techniques. Thus, the objectives of this study were: (I) to characterize the spatial distribution of soils physical attributes under rainfed and irrigated sugarcane cultivations; (II) to identify the minimum sampling for the determination of soil physical attributes; (III) to detect the effects of the different management on soil physical attributes based on the principal component analysis (PCA). The study was carried out in the agricultural area of the Carpina Sugarcane Experimental Station of the Federal Rural University of Pernambuco, 7º51’13”S, 35º14’10”W, characterized by a Typic Hapludult with sandy clay loam soil texture. The investigated plot, cultivated with sugarcane, included a rainfed and an irrigated treatment in which a sprinkler system was installed according to a 12x12m grid. The interval between consecutive watering was fixed in two days, whereas irrigation depth was calculated to replace crop evapotranspiration (ETc) and accounting for the effective precipitation of the period. Daily ETc was estimated based on crop coefficient and reference evapotranspiration (ETo) indirectly obtained through a class A evaporation pan. In both treatments, the soil spatial variability was determined according to a 56x32m grid, on 32 soil samples collected in the 0.0-0.1m soil layer, spaced 7x8m, and georeferenced with a global position system. The soil was physically characterized according to the following attributes: bulk density (BD), soil penetration resistance (SPR), macroporosity (Macro), mesoporosity (Meso), microporosity (Micro), total porosity (TP), saturated hydraulic conductivity (Ksat), gravimetric soil water content (SWCg), geometric mean diameter (GMD) and mean weight diameter (MWD). The results of the descriptive statistics showed that among the studied attributes, Ksat, SPR, and Macro presented higher CV values, equal to 63 and 69%, 35 and 40%, and 32 and 44%, under rainfed and irrigated conditions, respectively. The minimum sampling, adequate to characterize the different soil attributes, resulted in general smaller in the rainfed area, characterized by higher homogeneity. Thus, the GMD, SWCg (both with 2 points ha-1), and SPR (with 6 points ha-1) were identified as the soil physical attributes requiring the lowest sample density; on the other hand, MWD and Ksat, with 14 and 15 points ha-1, respectively, required the highest number of samples. Pearson’s correlation analysis evidenced that soil BD was the most influential physical attribute in the studied areas, with a significant and inverse effect in most of the investigated attributes. The geostatistical approach associated with the multivariate PCA provided to understand the relationships between the spatial distribution patterns associated with irrigated and rainfed management and soil physical properties.

O objetivo do presente estudo foi realizar um diagnóstico da comunidade do entorno do Parque Municipal do Bacaba, estabelecendo uma relação de proximidade com a população e buscando uma pré-compreensão de sua visão sobre o Parque e a Universidade do Estado de Mato Grosso. Foram aplicados questionários em 120 domicílios, representando uma população de 521 pessoas que vivem no entorno do Parque. Foi evidenciada baixa escolaridade, 27% cursaram o ensino fundamental e 39% não responderam. Entre os moradores, somente 42% visitaram o Parque ao menos uma vez. Entretanto, 55% consideram o Parque bem preservado, sendo provável uma consideração restrita à vegetação do entorno do Parque. Os moradores não sabem como contribuir com a preservação, além de não jogar lixo e não desmatar. A maioria (81%) demonstrou afetividade com o Parque e está ciente da importância do Parque para a qualidade de sua vida, mas desconhece a relação do Parque com a preservação e conservação da qualidade e quantidade da água do Córrego Bacaba. De forma geral, os moradores demonstraram envolvimento e pré-disposição positiva para ações de preservação do Parque, que são elementos essenciais para garantir o sucesso de futuras iniciativas ou ações educativas de ampla participação

Soil quality is essential for maintaining the sustainability of agro-ecosystems and ecosystem services provided by this natural resource. The present study aimed to assess the physical quality of soil through the characterization of the physical properties in grain production systems in the Southwest region of Piaui State, Brazil. The study was carried out in the Cerrado region of Piaui in four cities in areas of expansion of the agricultural frontier of the state: Baixa Grande do Ribeiro, Sebastiao Leal, Urucui and Bom Jesus. Soil samples were collected in April 2012, in areas of grain production under conventional and no-tillage systems. Adjacent areas with native vegetation were also sampled as reference. Bulk density, effective saturation, hydraulic conductivity, penetration resistance, porosity and aggregation were measured. Regardless of the type of soil management used, agricultural systems degrade soil physical quality. No-tillage showed higher bulk density, penetration resistance and aggregation, with lower total porosity, macroporosity and hydraulic conductivity. The physical quality of soil in the agricultural areas of the Cerrado region of Piaui was dependent on the soil texture, while silt, clay and organic matter were determinant for soil aggregation, mechanical resistance, total porosity and microporosity.

portuguesObjetivou-se caracterizar a macrofauna edafica sob diferentes cultivos comparando-os a vegetacao nativa de ecotono Cerrado/Caatinga no Sudoeste do Piaui. As areas estudadas foram: area sob cultivo de ata (Annona squamosa L.); capim andropogon com tres anos de cultivo; capim andropogon com seis anos de cultivo; milho irrigado sob pivo; capim napier e vegetacao nativa. Em cada area foram avaliadas as camadas de 0-0,1, 0,1-0,2 e 0,2-0,3m, inclusive a serapilheira de superficie, segundo recomendacoes do Tropical Soil Biology and Fertility Program (TSBF). A macrofauna edafica nos diferentes sistemas de uso do solo foi identificada ate o nivel de familias e a densidade media de cada taxon foi calculada para cada tipo de manejo do solo e camada. A estrutura da macrofauna edafica foi alterada negativamente nos diferentes cultivos quando comparadas com a vegetacao nativa de cerrado/caatinga, variando quanto a sua ocorrencia nas diversas camadas de solo. Houve correlacao entre os grupos funcionais com a distribuicao granulometrica e umidade do solo. O cultivo de capim napier favoreceu maior abundância da macrofauna edafica, porem com predominância das familias pertencente as ordens Isoptera e Hymenoptera. O milho irrigado sob pivo apresenta numero de familias da macrofauna edafica mais semelhante a vegetacao nativa e maior diversidade de familias em relacao aos demais cultivos estudados, reduzindo o impacto do uso antropico sobre a biodiversidade da macrofauna edafica. Palavras-chave: bioindicadores; capim napier; cultivo irrigado; invertebrados do solo; qualidade do solo EnglishThe aim of this study was to characterize the soil macrofauna under different crop systems and compare them to the macrofauna under the native vegetation of a Cerrado/Caatinga ecotone in southwestern Piaui State, Brazil. The areas studied included areas under sweetsop cultivation (Annona squamosa L.), andropogon grass with three years of use, andropogon grass with six years of use, pivot-irrigated corn, Napier grass, and native vegetation. In each area, soil layers of 0-0.1, 0.1-0.2, and 0.2-0.3m, including the surface litter, were evaluated following the Tropical Soil Biology and Fertility Program (TSBF) recommendations. The soil macrofauna from the different land-use systems were identified to the family level, and the mean density of each taxon was calculated for each soil-management type and layer. The structure of the soil macrofauna was negatively altered under the different crops in comparison to the native Cerrado/Caatinga vegetation, with macrofaunal occurrence varying in the different soil layers. A correlation existed between the functional groups and the soil grain-size distribution and moisture. Napier grass cultivation favored greater soil macrofaunal abundance, with a predominance of families belonging to the orders Isoptera and Hymenoptera. Number of soil macrofaunal families under pivot-irrigated corn was more like the number observed with the native vegetation, and corn also had greater family diversity compared to the other crops studied. Therefore, pivot-irrigated corn can reduce the impact of anthropogenic land use on the diversity of soil macrofauna. Key words: bioindicators; Napier grass; irrigated crop; soil invertebrates; soil quality

Submitted by Mario BC (mario@bc.ufrpe.br) on 2018-07-12T13:34:11Z No. of bitstreams: 1 Thiago Rodrigo Schossler de Souza.pdf: 2477210 bytes, checksum: a1c6fa0e387968e3eca6f73e711b68ae (MD5) Made available in DSpace on 2018-07-12T13:34:11Z (GMT). No. of bitstreams: 1 Thiago Rodrigo Schossler de Souza.pdf: 2477210 bytes, checksum: a1c6fa0e387968e3eca6f73e711b68ae (MD5) Previous issue date: 2017-02-22 Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq The knowledge of the spatial distribution of soil physical attributes, as well as practices of soil management and gypsum application is important to evaluate effects of agricultural operations on sugarcane productivity. In this context, the objective of this work was to study the best sample density, to determine the spatial variability, the effects of soil preparation with harrowing + subsoiling and the physical attributes of a dystrocohesive Yellow Argisol correlating with the productivity of sugarcane. In order to evaluate the spatial variability and sample density, a sample mesh was demarcated in a first cycle of sugarcane cultivation, where 32 equidistant samples were collected, spaced every 7 m. In order to evaluate the effects of the preparation and the gypsum on the physical attributes of the soil, an experiment was carried out in a randomized block design in a subdivided plots scheme with four replications, totalizing 32 experimental units. The treatments in the main plots were with mechanized preparation (harrowing + subsoiling) and the absence of soil preparation. In the subplots the doses of gypsum applied were 1; 2 and 4 t ha-1 plus the control (absence of gypsum), applied on surface to the haul before tilling the soil. The samples were collected at depths of 0-0.30 m and 0.30-0.60 m between the planting furrows. Tensile strength of the aggregates, weighted mean diameter, penetration resistance of soil, gravimetric moisture, bulk density, total porosity, macroporosity, microporosity, soil calcium content, soil water retention characteristic curve, adjustment parameters of the van Genuchten model, least limiting water range and sugarcane productivity. The minimum sample density to estimate sugarcane productivity was 14 samples per hectare and depended on the penetration resistance and total porosity of the soil. The natural densification of cohesive soils can be reduced by irrigation, favoring significant increases in productivity, independent of other soil physical attributes. The gypsum rates, in the management with harrowing and subsoiling, reduced the tensile strength of the soil aggregates. Among the soil physical attributes penetration resistance of soil was influenced by soil preparation with lower values in the mechanized plots. Soil preparation with subsoiling was efficient in increasing gypsum contents in depth. Subsoiling was more effective in increasing the critical soil bulk density range when used alone. The dose of gypsum with 2 Mg ha-1 improved the physical-water attributes of the soil, with greater availability of water to the plants, by increasing the critical bulk density of the soil, when prepared with subsoiling. The improvement in soil physical-water attributes due to the application of 2 Mg ha-1 increased cane-plant productivity. O conhecimento da distribuição espacial dos atributos físicos do solo, bem como as práticas de manejo do solo e da aplicação de gesso é importante para avaliar efeitos das operações agrícolas sobre a produtividade da cana-de-açúcar. Nesse contexto, o objetivo deste trabalho foi indicar a melhor densidade amostral, determinar a variabilidade espacial, os efeitos do preparo do solo com gradagem + subsolagem e da gessagem nos atributos físicos em um Argissolo Amarelo distrocoeso, correlacionando com a produtividade da cana-de-açúcar. Para avaliar a variabilidade espacial e densidade amostral foi demarcada uma malha amostral em cultivo de primeiro ciclo da cana-de-açúcar, onde foram coletadas 32 amostras equidistantes, espaçadas a cada 7 m. Para avaliar dos efeitos do preparo e da gessagem nos atributos físicos do solo foi conduzido um experimento em delineamento de blocos ao acaso em esquema de parcelas subdivididas com quatro repetições, totalizando 32 unidades experimentais. Os tratamentos nas parcelas principais foram: com preparo mecanizado (gradagem + subsolagem) e a ausência de preparo do solo. Nas subparcelas, as doses de gesso aplicadas foram: 1; 2 e 4 Mg ha-1; mais o controle (ausência de gesso), aplicadas em superfície à lanço, antes do preparo do solo. As amostras foram coletadas nas camadas entre as profundidades de 0-0,30 m e 0,30-0,60 m entre os sulcos de plantio. Foram avaliados a resistência tênsil dos agregados, diâmetro médio ponderado, resistência do solo à penetração de raízes, umidade gravimétrica, densidade do solo, porosidade total, macroporosidade, microporosidade, teor de cálcio no solo, a curva característica de retenção de água no solo, parâmetros de ajuste do modelo de van Genuchten, intervalo hídrico ótimo e produtividade de colmos da cana-de-açúcar. A densidade amostral mínima para estimar a produtividade da cana-de-açúcar foi de 14 amostras por hectare e dependeu da resistência à penetração e porosidade total do solo. O adensamento natural dos solos coesos pode ser reduzido pela irrigação, favorecendo aumentos significativos de produtividade, independente de outros atributos físicos do solo. As doses de gesso, no manejo com gradagem e subsolagem, reduziram a resistência tênsil dos agregados do solo. Entre os atributos físicos do solo, a sua resistência à penetração foi influenciada pelo preparo do solo, com menores valores nas parcelas mecanizadas. O preparo do solo com subsolagem foi eficiente em aumentar os teores de gesso em profundidade. A subsolagem foi mais efetiva em ampliar a faixa da densidade crítica do solo quando utilizada isoladamente. A dose de gesso com 2 Mg ha-1 melhorou os atributos físico-hídricos do solo, com maior disponibilidade de água às plantas, pelo aumento da densidade crítica do solo, quando preparado com subsolagem. A melhoria nos atributos físico-hídricos do solo, devido a aplicação de gesso na dose 2 Mg ha-1, aumentou a produtividade de colmos da cana-planta.

Resumo O objetivo deste trabalho foi caracterizar a macrofauna edáfica em sistemas de produção de grãos sob plantio direto e convencional no Sudoeste do Piauí, na região de Matopiba. Amostras de solo foram coletadas nas camadas de 0,0-0,1, 0,1-0,2 e 0,2-0,3 m, com serrapilheira, em áreas cultivadas predominantemente com milho e soja, sob preparo convencional e plantio direto, em solos com diferentes texturas. Remanescentes de vegetação nativa adjacentes foram amostrados como referência. A macrofauna edáfica nos diferentes sistemas de uso do solo foi identificada até o nível de famílias, as quais foram agrupadas de acordo com suas funções ecológicas. Os grupos mais abundantes nas áreas amostradas foram Isoptera, Hymenoptera e Coleoptera, este com o maior número de famílias. A análise de componentes principais revelou que os grupos funcionais geófago/bioturbador, fitófago/praga e predador/parasita estão associados a solos de textura argilo-siltosa; enquanto o grupo detritívoro/decompositor, a solos mais arenosos. Os sistemas de manejo do solo alteram a estrutura da comunidade de macroinvertebrados edáficos em relação à condição natural de Cerrado. O plantio direto proporciona maior abundância e riqueza de espécies que o preparo convencional, e minimiza o impacto de sistemas agrícolas sobre a biodiversidade da macrofauna edáfica. Abstract The objective of this work was to characterize the edaphic macrofauna in agricultural grain production systems under no-tillage and conventional tillage, in the Shoutheastern state of Piauí, in the Matopiba region, Brazil. Soil samples were taken from the 0.0-0.1, 0.1-0.2, and 0.2-0.3-m layers, with litter, in areas predominantly cropped with corn and soybean, under conventional and no-tillage systems, in soils with different textures. Fragments of native vegetation in adjacent areas were used as a reference. The edaphic macrofauna in the different land uses was identified down to family level, and the families were grouped according to their ecological functions. The most abundant groups in the sampled areas were Isoptera, Hymenoptera, and Coleoptera, the latter with the highest number of families. Principal component analysis revealed that the functional groups geophages/bioturbators, phytophages/pests, and predators/parasites were associated with clayey-silty soils, and detritivores/decomposers with sandy soils. Soil management systems change the community structure of edaphic macroinvertebrates in comparison with the natural Cerrado condition. No-tillage system promotes greater abundance and species richness than conventional tillage, and minimizes the impact of agricultural systems on edaphic macrofauna biodiversity.

Objetivou-se avaliar o efeito do biochar como condicionador de substrato para a produção de mudas de eucalipto. O experimento foi conduzido em estufa utilizando delineamento experimental de blocos ao acaso em esquema fatorial 5 x 2, sendo os fatores constituídos por cinco concentrações de biochar (0; 7,5; 15; 30 e 60% do v/v) adicionadas ao substrato comercial Germinar® e duas espécies de eucalipto (Eucalyptus citriodora e Eucalyptus urophylla), com 4 repetições. Aos 75, 90 e 120 dias após a semeadura (DAS) avaliou-se o diâmetro do coleto e altura de plantas e ao final do experimento (120 DAS) procedeu à avaliação da fitomassa fresca da parte aérea e radicular, fitomassa seca da parte aérea e radicular e os parâmetros morfológicos relação altura de plantas/diâmetro do coleto, fitomassa seca da parte aérea/fitomassa seca de raízes e índice de qualidade de Dickson. De maneira geral os substratos acrescidos de 7,5% de biochar proporcionaram melhor desenvolvimento das mudas, com destaque para E. citriodora, que apresentou os melhores resultados para as características avaliadas. Avaliando os parâmetros morfológicos que atuam como principais componentes na qualidade de mudas, E. citriodora foi superior a E. urophylla. Concentrações de biochar acima de 30% prejudicaram o desenvolvimento das mudas.