Abstract The cocoa cabruca is as an agroforestry system with a density of trees equal to or greater than twenty individuals of native species per hectare cultivated in association with native or exotic trees in a discontinuous and random way in the Atlantic Forest biome.It is difficult to separate areas of cabruca cacao from the Dense Ombrophilous Forest by existing satellite imaging techniques.The study was developed in the southern region of Bahia, on two properties in the municipalities of Ilhéus and Uruçuca.The image processing methodology involved the Agisoft Photoscan software, with the multiresolution algorithm, the analysis of digital image data was performed to extract the objects and with the Feature Space Optimization tool, the set of variables that presented the best separation between land use classes.The use of UAVs was effective in classifying the mapped areas, and its use was proposed as an auxiliary tool in the application of the Decree. biomeIt biome It techniquesThe techniques Bahia UruçucaThe Uruçuca software algorithm classesThe classes Decree

ABSTRACT Soil temperature is a physical property of great agricultural importance in the soil-plant relationship and in energy exchange with the atmosphere. This study was conducted in a degraded Cambissolo Háplico Ta Eutrófíco (Cambisol; Inceptisol) in the Irecê Identity Territory, Bahia, Brazil, aiming to evaluate the hourly, daily, and monthly fluctuations of soil temperature at depth, and soil thermal diffusivity in the castor bean crop. Hourly soil temperature data from February 4, 2014, to September 30, 2015, were obtained by using thermocouple sensors (copper-constantan) horizontally installed at 0.05, 0.10, and 0.20 m depths. Soil thermal diffusivity was estimated by phase and amplitude methods. Results showed that, for most days, the soil temperature was at the level recommended for castor bean. The maximum and minimum hourly and daily soil temperatures were observed in October and July, respectively, and the maximum soil temperature values occurred at 4 p.m. (0.05 m), 5 p.m. (0.10 m), and 7 p.m. (0.20 m). Soil temperature variability is low, requiring few measurement points to estimate this factor in an area. The amplitude method led to soil thermal diffusivity values compatible with results in the literature. The absence of a relationship between thermal diffusivity and soil moisture was attributed to the clay-loam soil texture, predominance of micropores, and iron oxides allowing greater approximation to the soil particles, with high thermal diffusivity even under low soil moisture conditions.

Na Bacia Hidrográfica Água Fria, em Barra do Choça (BA), o desenvolvimento da lavoura cafeeira e da pastagem tem sido feito mediante a supressão da vegetação nativa, inclusive em áreas de proteção ambiental. O objetivo deste trabalho foi avaliar os atributos físicos: granulometria, argila dispersa em água, grau de floculação, diâmetro médio ponderado e índice de estabilidade de agregados e C orgânico dos solos submetidos a diferentes tipos de uso da terra na referida bacia. Para as amostragens, foram selecionadas seis glebas: duas de café (cultivo mecanizado e não mecanizado), duas de pastagens e duas de matas nativas, empregadas como referência. Constatou-se que o uso da terra diminuiu a estabilidade de agregados, evidenciada pela redução no diâmetro médio ponderado, pelo aumento dos agregados de menor tamanho e pelos menores teores de C orgânico na seqüência mata-pastagem-cafezal.

In the watershed Água Fria, in Barra do Choça (BA), native vegetation and environmentally protected areas have been replaced by coffee and pasture cultivation. This study evaluated the physical characteristics, particle size distribution, water dispersible clay, flocculation, mean weight diameter and aggregate stability index and organic C concentration of soils under different land uses, in the area surroundings the above watershed. Soil samples were collected from six different fields: two coffee plantations (manual and mechanical cultivation), two pastures and two native forest areas were used as references. The different land uses reduced the aggregate stability, as indicated by the reduction of the mean weight diameter, increase of small-sized aggregates and lower organic C contents, in the order forest > pasture > coffee plantation.

O aprofundamento do sistema radicular dos citros é importante para aumentar a produtividade e a longevidade dessa cultura, principalmente em solos que apresentam horizontes coesos subsuperficiais. Assim, o objetivo deste trabalho foi avaliar a distribuição das raízes da laranjeira 'Hamlin' enxertada em limoeiro 'Cravo', com 15 anos de idade, em uma toposseqüência de tabuleiro de Sapeaçu-BA, composta por Latossolo Amarelo argissólico (LAx) e Argissolo Amarelo (PAx), ambos coesos, e Argissolo Acinzentado (PAC), não coeso. Em 2001, retiraram-se amostras de raízes em uma planta no LAx e no PAx e em duas no PAC, em quatro horizontes, em quatro pontos na linha e em cinco na entrelinha, distanciados por 0,50 m, usando-se um cilindro de aço de 1,20 m de comprimento e 0,085 m de diâmetro. As raízes foram digitalizadas em escaner e processadas no aplicativo GSRoot. As raízes da laranjeira 'Hamlin' enxertada em limoeiro 'Cravo' apresentaram grande sensibilidade à coesão, sendo a densidade de raízes 3,4 a 4,1 vezes maior no solo PAC, não coeso. A densidade das raízes encontradas nos horizontes superficiais do LAx e do PAx foi próxima daquela do horizonte mais profundo do PAC. A profundidade efetiva do sistema radicular, até onde se encontraram 80 % das raízes, foi maior no PAC não coeso, e a distância efetiva do sistema radicular, até onde se encontraram 80 % das raízes a partir do tronco, foi maior no PAx coeso, que foi o solo que apresentou a menor profundidade efetiva das raízes. Nos três solos, houve predominância de raízes com diâmetros < 1 mm, seguidas daquelas com diâmetros entre 1 e 2 e > 2 mm.

The deepening of citrus root system is important to increase crop productivity and longevity, especially in soils with subsurface cohesive horizons. The objective of this study was to evaluate the root distribution of 'Hamlim' sweet orange grafted onto Rangpur lime. The 15 year-old plants were located in a coastal plain soil toposequence in Sapeaçu county, Bahia, Brazil. The soils were an argisolic Yellow Latosol (LAx; Oxisol) and a Yellow Argisol (PAx; Ultisol), both cohesive, and a non-cohesive Gray Argisol (PAC; Ultisol). In 2001, root samples were collected from one plant in the LAx and from one plant in the PAx, and from two plants in the PAC. Samples were collected in four horizons, four points in the row and five points in the inter-rows, spaced at 0.50 m, using a steel cylinder with a length of 1.20 m and diameter of 0.085 m. The collected roots were scanned and processed using the GSRoot software. 'Hamlim' sweet orange roots grafted onto Rangpur lime were highly sensitive to soil cohesion. The root density in the PAC was 3.4 to 4.1 times higher than in the LAx and PAx, respectively. Root density in the LAx and PAx surface horizons was close to that in the deepest horizon of the PAC. The effective depth root system, where 80 % of the roots can be found, was higher in the PAC, non-cohesive soil, while the effective distance, where 80 % of the roots measured from the tree trunk can be found, was higher in the PAx, cohesive soil. In the PAx the effective depth of the root system was the smallest. In the three soils the roots with diameter < 1 mm were predominant, followed by those with diameter between 1 and 2 and > 2 mm.

O trabalho teve como objetivo avaliar quinzenalmente, em 1996 e 1997, a variação do potencial total da água ao longo do tempo, em solos de uma toposseqüência de tabuleiro localizada em Sapeaçu, BA. Esta toposseqüência tinha as seguintes características: a) comprimento de 190 m; b) declividade média de 0,097 m m-1; c) cultivo com laranja; d) Latossolo Amarelo argissólico coeso, no terço superior; e) Argissolo Amarelo coeso, no terço médio; f) Argissolo Acinzentado não coeso, no terço inferior. A umidade do solo foi medida com sonda de nêutrons, nas profundidades de 0,30, 0,70, 1,10 e 1,50 m. Com base nas respectivas curvas de retenção, obteve-se o potencial matricial e, em seguida, o potencial total da água, para cada solo, profundidade e tempo. A camada coesa dificulta o fluxo de água no solo, tanto no processo de molhamento como no de secamento. Em conseqüência, o potencial total da água em solos com camada coesa varia bruscamente na camada mais superficial, ao longo do tempo, e mais lentamente nas camadas mais profundas. Em solo não coeso, a variação brusca do potencial ocorre apenas na camada mais superficial. O limite de tensão de água no solo de -1.500 kPa como sendo o ponto de murchamento permanente não se aplica à cultura dos citros.

The objective of this work was to evaluate, fortnightly, during 1996/1997, the total soil water potential variation in a tableland topsequence in Sapeaçu county, BA, Brazil. This topsequence had the following characteristics: a) length of 190 m; b) slope of 0.097 m m-1; c) orange as growing crop; d) the upper third with a cohesive argisolic Yellow Latosol; e) the middle third with a cohesive Yellow Argisol; and f) the lower third with a non-cohesive Gray Argisol. Soil water was estimated by neutron probe at depths of0.30, 0.70, 1.10, and 1.50 m. Based on water retention curves, matric potential and, in sequence, total soil water potential were determined, for each soil and depth in different times. The cohesive layer makes difficult the water flow in the soil profile, both in the wetting and in the drying processes. Consequently, the total water potential in soils with cohesive layer changed abruptly in the most superficial layer, during the time, and slowing in the deepest layers. In non-cohesive soil, the water potential changed abruptly only in the most superficial layer. The -1,500 kPa limit of soil water pressure as permanent wilting point is not applied to orange crop.

Desenvolveu-se um estudo em uma toposseqüência de tabuleiro cultivada com laranjeiras 'Hamlin', localizada no Município de Sapeaçu, BA, com o objetivo de avaliar algumas propriedades físico-hídricas de um Latossolo Amarelo argissólico e de um Argissolo Amarelo, ambos apresentando aspecto coeso, e também de um Argissolo Acinzentado. Para isso, foram estudados três perfis, um para cada tipo de solo. Amostras deformadas e indeformadas foram coletadas em cada horizonte, com três repetições. Analisaram-se a granulometria, argila dispersa em água, densidade do solo, densidade de partículas, carbono orgânico, porosidade total, macroporosidade, microporosidade, estabilidade de agregados e condutividade hidráulica saturada. Os horizontes coesos do Latossolo Amarelo argissólico e do Argissolo Amarelo apresentaram menor diâmetro médio ponderado de agregados e maior quantidade de microporos, refletindo em menor condutividade hidráulica saturada. O Argissolo Acinzentado apresentou maior macroporosidade e condutividade hidráulica saturada.

A study was carried out in Sapeaçu, State of Bahia, Brazil, on a tableland toposequence cultivated with sweet orange 'Hamlin', to determine the soil physical and hydraulic properties. The toposequence consisted of an Argisolic Yellow Latosol, a Yellow Argisol, and a Gray Argisol. For each soil type, one soil profile was studied. Soil samples were collected in each horizon with three replications. These soil samples were analyzed for texture, water clay dispersion, bulk density, particle density, organic carbon, total porosity, macroporosity, microporosity, aggregates analyses, and saturated hydraulic conductivity. The dense horizons of the Argisolic Yellow Latosol and the Yellow Argisol showed the lowest meanweight diameter of aggregates and higher values of microporosity, which result in lower values of saturated hydraulic conductivity. The Gray Argisol presented higher values of macroporosity and saturated hydraulic conductivity.