RESUMO O feijão-caupi (Vigna unguiculata [L.] Walp.) é uma das mais importantes leguminosas produzidas em regiões tropicais e subtropicais do mundo, principalmente nos países em desenvolvimento da África, América Latina e Ásia. Para um grande segmento da população mundial é a principal fonte de proteínas, calorias, fibras alimentares, minerais e vitaminas. Possui ainda compostos bioativos, destacando-se os compostos fenólicos. É produzido no Norte e Nordeste, consumido também em outras regiões do país e apresenta grande importância para os agricultores que sobrevivem desta cultura. O objetivo do presente estudo foi identificar e quantificar os compostos fenólicos no feijão-caupi, cultivar BRS Xiquexique. Tal determinação permitirá conhecer características funcionais do feijão-caupi, como fonte de antioxidantes, o que será de primordial importância para agregar valor funcional e nutricional a este alimento e ampliar as formas de consumo. Os extratos foram analisados por CLAE em equipamento modelo LC-20AT, com injetor manual. Para as análises foram preparadas soluções padrões com os ácidos fenólicos puros, tais como: ácido gálico, quercetina, ácido cafeico, ácido clorogênico, ácido ferúlico, ácido p-cumárico, catequina e epicatequina. Foram identificados catequina (2,07 ± 0,329 mg 100 g-1), epicatequina (0,48 ± 0,130 mg 100 g-1), ácido gálico (67,19 ± 6,200 mg 100 g-1), ácido ferúlico (32,07 ± 0,753 mg 100 g-1) e ácido clorogênico (3,08 ± 0,489 mg 100 g-1) em concentrações importantes. Concluiu-se que a cultivar BRS Xiquexique contêm compostos funcionais, destacando-se o ácido gálico e o ácido ferúlico com maiores teores, comprovando o potencial antioxidante do feijão-caupi. | ABSTRACT Cowpea (Vigna unguiculata [L.] Walp.) is one of the most important legumes produced in tropical and subtropical regions throughout the world, especially in the developing countries in Africa, Latin America, and Asia. It is the main source of protein, calories, dietary fiber, minerals, and vitamins for a large segment of the world population. Cowpea is also a potential functional food with a range of bioactive compounds, including phenolic compounds. This legume is grown mainly in the North and Northeast regions of Brazil, but is also consumed in other regions, and is thus important for the farmers who depend on this crop for income. This study identified and quantified phenolic compounds in the cowpea cultivar BRS Xiquexique. Such quantification reveals the functional characteristics of cowpeas, mainly as a source of antioxidants, which will be essential to add value to this food and to expand its forms of consumption. The extracts were analyzed using an HPLC model LC-20AT, equipped with a manual injector. For the HPLC analysis, standard solutions were prepared with pure phenolic acids such as gallic acid, quercetin, caffeic acid, chlorogenic acid, ferulic acid, p-coumaric acid, catechin, and epicatechin. The major phenolic compounds identified were catechin (2.07± 0.329 mg 100 g-1), epicatechin (0.48 ± 0.130 mg 100 g-1), gallic acid (67.19 ± 6.200 mg 100 g-1), ferulic acid (32.07 ± 0.753 mg 100 g-1), and chlorogenic acid (3.08 ± 0.489 mg 100 g-1). We observed that the BRS Xiquexique cultivar contains functional phenolic compounds, especially gallic acid and ferulic acid, demonstrating the antioxidant potential of cowpea.

Cowpea (Vigna unguiculata L. Walp.) is one of the most important legumes produced in tropical and subtropical regions throughout the world, especially in the developing countries in Africa, Latin America, and Asia. It is the main source of protein, calories, dietary fiber, minerals, and vitamins for a large segment of the world population. Cowpea is also a potential functional food with a range of bioactive compounds, including phenolic compounds. This legume is grown mainly in the North and Northeast regions of Brazil, but is also consumed in other regions, and is thus important for the farmers who depend on this crop for income. This study identified and quantified phenolic compounds in the cowpea cultivar BRS Xiquexique. Such quantification reveals the functional characteristics of cowpeas, mainly as a source of antioxidants, which will be essential to add value to this food and to expand its forms of consumption. The extracts were analyzed using an HPLC model LC-20AT, equipped with a manual injector. For the HPLC analysis, standard solutions were prepared with pure phenolic acids such as gallic acid, quercetin, caffeic acid, chlorogenic acid, ferulic acid, p-coumaric acid, catechin, and epicatechin. The major phenolic compounds identified were catechin (2.07± 0.329 mg 100 g-1), epicatechin (0.48 ± 0.130 mg 100 g-1), gallic acid (67.19 ± 6.200 mg 100 g-1), ferulic acid (32.07 ± 0.753 mg 100 g-1), and chlorogenic acid (3.08 ± 0.489 mg 100 g-1). We observed that the BRS Xiquexique cultivar contains functional phenolic compounds, especially gallic acid and ferulic acid, demonstrating the antioxidant potential of cowpea.

ABSTRACT Nitisols are livelihood sources of agricultural and socio-economic development in several underdeveloped countries worldwide, including Brazil. Brazilian Nitisols are usually associated with basaltic rocks found in the Southern and Southeastern regions of the country. However, Nitisols derived from basalt also occur on the southern coast of Pernambuco state, a region under full urban, agricultural, and industrial development. Aiming to understand the relationship between climate and attributes of Nitisols from the southern coast of Pernambuco, we performed morphological descriptions, physical and chemical analyzes, iron selective extraction, and soil mineralogy (sand, silt, and clay) for three basaltic soil profiles along a land slope. The results suggest a strong weathering of the profiles due to climate conditions, besides a great loss of basic cations and xanthization process, resulting in the natural genesis of acric Nitisols with yellowish coloration, which has not been yet cataloged for this soil order in the Brazilian taxonomic system. In addition, there is a variation for physical attributes of Nitisols along the slope. | RESUMO Os Nitossolos dão suporte ao desenvolvimento agrícola e socioeconômico de muitos países subdesenvolvidos do mundo, incluindo o Brasil. Os Nitossolos brasileiros estão geralmente associados às rochas basálticas das regiões Sul e Sudeste. Entretanto, Nitossolos derivado de basalto também ocorrem na costa sul de Pernambuco, uma região em pleno desenvolvimento urbano, agrícola e industrial. Objetivando compreender as relações entre o clima e os atributos dos Nitossolos da costa sul de Pernambuco, foram realizadas descrições morfológicas, análises físicas e químicas, extrações seletivas de ferro e a determinação da mineralogia das frações areia, silte e argila de três perfis derivados de basalto ao longo de uma vertente. Os resultados demonstram que o clima da região implica em forte intemperização dos perfis, em grande perda de bases e favorece o processo de xantização, resultando na singular gênese de Nitossolos com matizes amarelados e caráter ácrico, fato que até o momento ainda não foi catalogado para esta ordem no sistema taxonômico brasileiro. Os resultados também demonstram a variação dos atributos físicos dos Nitossolos ao longo da vertente.

Nitisols are livelihood sources of agricultural and socio-economic development in several underdeveloped countries worldwide, including Brazil. Brazilian Nitisols are usually associated with basaltic rocks found in the Southern and Southeastern regions of the country. However, Nitisols derived from basalt also occur on the southern coast of Pernambuco state, a region under full urban, agricultural, and industrial development. Aiming to understand the relationship between climate and attributes of Nitisols from the southern coast of Pernambuco, we performed morphological descriptions, physical and chemical analyzes, iron selective extraction, and soil mineralogy (sand, silt, and clay) for three basaltic soil profiles along a land slope. The results suggest a strong weathering of the profiles due to climate conditions, besides a great loss of basic cations and xanthization process, resulting in the natural genesis of acric Nitisols with yellowish coloration, which has not been yet cataloged for this soil order in the Brazilian taxonomic system. In addition, there is a variation for physical attributes of Nitisols along the slope.

RESUMO Os resíduos de plantas daninhas são importantes para a ciclagem de nutrientes nos agroecossistemas. A quantificação desta potencial fonte de nutrientes pode influenciar o manejo dessas plantas e as práticas de adubação. Nicandra physalodes (L.) Gaertn. (joá-de-capote) é uma planta daninha de ciclo curto com rápido crescimento e grande capacidade de acumular biomassa. Dessa forma, objetivou-se conhecer o potencial de acúmulo e ciclagem de nutrientes de N. physalodes e avaliar se o aumento de nitrogênio (N), fósforo (P) e potássio (K) no solo influenciam essas características. Utilizou-se delineamento de blocos casualizados, arranjado em parcelas subdivididas com três repetições. As parcelas foram constituídas de quatro doses crescente de N, P e K (Dose 1 - 0, 0,3 e 17,2; Dose 2 - 30, 450,3 e 75,4; Dose 3 - 60, 900,3 e 133,4 e Dose 4 - 120, 1800,3 e 249,68 mg dm-3) e as subparcelas de dez épocas de coleta das plantas (26, 33, 40, 47, 54, 61, 76, 91, 106 e 121 dias após emergência). O aumento nos níveis de N, P e K no solo proporcionou maiores produções de massa seca e acúmulo total desses macronutrientes em plantas de N. physalodes, sendo que os maiores acúmulos foram de K e N. A adubação não influenciou os teores de fibra em detergente neutro (FDN), fibra em detergente ácido (FDA) e a relação carbono/ nitrogênio da planta. N. physalodes apresenta baixa relação C/N, o que aliado aos baixos teores de FDN e FDA e ao bom acúmulo de nutrientes, sugere que o material vegetal dessa planta seja rapidamente decomposto, proporcionando uma ciclagem rápida de nutrientes no solo. | ABSTRACT Weed residues can influence nutrient cycling in agroecosystems. Quantifying this potential nutrient source may influence weed control and fertilisation practices. Nicandra physalodes (L.) Gaertn. is a weed with a short life cycle and a great ability to accumulate dry matter. Field observations suggest that N. physaloides residues are easily decomposed in soil. The objective of this study was to evaluate the effect of increasing of N, P and K doses on the growth of N. physalodes, as well as the nutrient content, chemical characteristics and C/N ratio of the weed. A randomised block design, arranged in split-plot with three replications, was utilised. The main plots were given four doses of NPK (Dose 1 - 0, 0.3 and 17.2 mg dm-3; Dose 2 - 30, 450.3 and 75.4 mg dm-3; Dose 3 - 60, 900.3 and 133.4 mg dm-3; and Dose 4 - 120, 1800.3 and 249.68 mg dm-3), and the subplots were harvested at ten time points after emergence (26, 33, 40, 47, 54, 61, 76, 91, 106 and 121 days). Higher dry matter production and N, P and K content were observed in plants grown on higher levels of fertiliser. The increase of N, P and K levels in the soil resulted in greater total accumulation of these macronutrients. The highest macronutrient contents were K and N. The treatments did not affect neutral detergent fibre (NDF), acid detergent fibre (ADF) and C/N ratio of plant. N. physalodes had low C/N ratio, low NDF and ADF levels, and great nutrient accumulation, suggesting that this plant is quickly decomposed, providing a rapid cycling of nutrients.

Weed residues can influence nutrient cycling in agroecosystems. Quantifying this potential nutrient source may influence weed control and fertilisation practices. Nicandra physalodes (L.) Gaertn. is a weed with a short life cycle and a great ability to accumulate dry matter. Field observations suggest that N. physaloides residues are easily decomposed in soil. The objective of this study was to evaluate the effect of increasing of N, P and K doses on the growth of N. physalodes, as well as the nutrient content, chemical characteristics and C/N ratio of the weed. A randomised block design, arranged in split-plot with three replications, was utilised. The main plots were given four doses of NPK (Dose 1 - 0, 0.3 and 17.2 mg dm-3; Dose 2 - 30, 450.3 and 75.4 mg dm-3; Dose 3 - 60, 900.3 and 133.4 mg dm-3; and Dose 4 - 120, 1800.3 and 249.68 mg dm-3), and the subplots were harvested at ten time points after emergence (26, 33, 40, 47, 54, 61, 76, 91, 106 and 121 days). Higher dry matter production and N, P and K content were observed in plants grown on higher levels of fertiliser. The increase of N, P and K levels in the soil resulted in greater total accumulation of these macronutrients. The highest macronutrient contents were K and N. The treatments did not affect neutral detergent fibre (NDF), acid detergent fibre (ADF) and C/N ratio of plant. N. physalodes had low C/N ratio, low NDF and ADF levels, and great nutrient accumulation, suggesting that this plant is quickly decomposed, providing a rapid cycling of nutrients.

ABSTRACT Information about the response of onion to different potassium doses may contribute to optimizing the use of fertilizers and, consequently, make the activity more profitable and environmentally sustainable. In this context, the aim of this study was to evaluate the effects of doses of potassium on onion yields. Two field experiments were carried out in the periods of September to December 2012 and April to July 2013. The experimental design used was completely randomized blocks with four replications. The treatments corresponded to the potassium doses (0, 36, 72, 108, 144 and 180 kg ha-1 of K2O). Potassium fertilization promoted an increase in the content of K in the leaf, commercial and total yield, with the maximum obtained in the dose of 180 kg ha-1 of K2O. The maximum overall and commercial yields were respectively 54.69 and 54.12 t ha-1 in the experiment of September to December 2012 and 47.39 and 46.39 t ha-1 in that of April to July 2013. | RESUMO Informações sobre a reposta da cebola a diferentes doses de potássio podem contribuir para a otimização do uso de fertilizantes e, consequentemente, tornar a atividade mais rentável e ambientalmente sustentável. Nesse contexto, o objetivo do trabalho foi avaliar os efeitos de doses de potássio na produtividade da cebola. Para isso dois experimentos de campo foram realizados nos períodos de setembro a dezembro de 2012 e abril a julho de 2013 O delineamento experimental foi em blocos casualizados completos com quatro repetições. Os tratamentos corresponderam às doses de potássio (0, 36, 72, 108, 144 e 180 kg ha-1 de K2O). A adubação potássica promoveu aumento do teor de K na folha, produtividade comercial total, com o máximo obtido na dose de 180 kg ha-1 de K2O. As produtividades máximas totais e comerciais foram respectivamente de 54,69 e 54,12 t ha-1 no experimento de setembro a dezembro de 2012 e 47,39 e 46,39 t ha-1 de abril a julho de 2013.

Information about the response of onion to different potassium doses may contribute to optimizing the use of fertilizers and, consequently, make the activity more profitable and environmentally sustainable. In this context, the aim of this study was to evaluate the effects of doses of potassium on onion yields. Two field experiments were carried out in the periods of September to December 2012 and April to July 2013. The experimental design used was completely randomized blocks with four replications. The treatments corresponded to the potassium doses (0, 36, 72, 108, 144 and 180 kg ha-1 of K2O). Potassium fertilization promoted an increase in the content of K in the leaf, commercial and total yield, with the maximum obtained in the dose of 180 kg ha-1 of K2O. The maximum overall and commercial yields were respectively 54.69 and 54.12 t ha-1 in the experiment of September to December 2012 and 47.39 and 46.39 t ha-1 in that of April to July 2013.

ABSTRACT Spatial variability of soil attributes affects crop development. Thus, information on its variability assists in soil and plant integrated management systems. The objective of this study was to assess the spatial variability of the soil apparent electrical conductivity (ECa), electrical conductivity of the saturation extract (ECse), water content in the soil (θ) and soil texture (clay, silt and sand) of a sugarcane crop area in the State of Pernambuco, Brazil. The study area had about 6.5 ha and its soil was classified as orthic Humiluvic Spodosol. Ninety soil samples were randomly collected and evaluated. The attributes assessed were soil apparent electrical conductivity (ECa) measured by electromagnetic induction with vertical dipole (ECa-V) in the soil layer 0.0.4 and horizontal dipole (ECa-H) in the soil layer 0.0-1.5 m; and ECse, θ and texture in the soil layers 0.0-0.2 m and 0.2-0.4 m. Spatial variability of the ECa was affected by the area relief, and had no direct correlation with the electrical conductivity of the saturation extract (ECse). The results showed overestimated mean frequency distribution, with means distant from the mode and median. The area relief affected the spatial variability maps of ECa-V, ECa-H, ECse and θ, however, the correlation matrix did not show a well-defined cause-and-effect relationship. Spatial variability of texture attributes (clay, site and sand) was high, presenting pure nugget effect. | RESUMO A variabilidade espacial dos atributos do solo, interferem sobre o desenvolvimento dos cultivos. Assim, o conhecimento dessa variabilidade permite o manejo integrado de solo e planta. Objetivou-se determinar a variabilidade espacial da condutividade elétrica aparente (CEa), condutividade elétrica do extrato de saturação (CEes), conteúdo de água (θ) e textura (argila, silte e areia) do solo em uma área cultivada com cana-de-açúcar, no Estado de Pernambuco. A área de estudo possui cerca de 6,5 ha e o solo da área é um Espodossolo Humilúvico órtico. As amostras de solo foram avaliadas em 90 pontos de amostragem distribuídos aleatoriamente. Foram amostrados os seguintes atributos: condutividade elétrica aparente (CEa) medida por indução eletromagnética (dipolo vertical: CEa-V e dipolo horizontal: CEa-H) nas camadas de 0,0-0,4 m e 0,0-1,5 m de profundidade respectivamente. Os demais atributos foram medidos nas camadas de 0,0-0,2 m e 0,2-0,4 m de profundidade (CEes, θ, argila, silte e areia). A variabilidade espacial da condutividade elétrica aparente do solo medida por indução eletromagnética (CEa-V e CEa-H) foi influenciada pelo relevo, não apresentando relação direta com a condutividade elétrica do extrato de saturação do solo (CEes). Os atributos em estudo apresentaram distribuição de frequência com média superestimada, com valores de média se distanciando dos valores de moda e mediana. O relevo influenciou os mapas de variabilidade espacial da CEa-V, CEa-H, CEes e θ, apesar da matriz de correlação não demonstrar relação de causa e efeito bem definida. Os atributos texturais (argila, site e areia) apresentaram elevada variabilidade espacial, apresentando efeito pepita puro (EPP).

Spatial variability of soil attributes affects crop development. Thus, information on its variability assists in soil and plant integrated management systems. The objective of this study was to assess the spatial variability of the soil apparent electrical conductivity (ECa), electrical conductivity of the saturation extract (ECse), water content in the soil (θ) and soil texture (clay, silt and sand) of a sugarcane crop area in the State of Pernambuco, Brazil. The study area had about 6.5 ha and its soil was classified as orthic Humiluvic Spodosol. Ninety soil samples were randomly collected and evaluated. The attributes assessed were soil apparent electrical conductivity (ECa) measured by electromagnetic induction with vertical dipole (ECa-V) in the soil layer 0.0.4 and horizontal dipole (ECa-H) in the soil layer 0.0-1.5 m; and ECse, θ and texture in the soil layers 0.0-0.2 m and 0.2-0.4 m. Spatial variability of the ECa was affected by the area relief, and had no direct correlation with the electrical conductivity of the saturation extract (ECse). The results showed overestimated mean frequency distribution, with means distant from the mode and median. The area relief affected the spatial variability maps of ECa-V, ECa-H, ECse and θ, however, the correlation matrix did not show a well-defined cause-and-effect relationship. Spatial variability of texture attributes (clay, site and sand) was high, presenting pure nugget effect.

RESUMO A curva característica de água no solo (CCAS) constitui importante ferramenta no manejo da água na agricultura irrigada. Entretanto, vale ressaltar que fatores como textura e estrutura do solo influenciam seu comportamento.Há informações na literatura que ciclos de umedecimento e secagem alteram a CCAS. Saliente-se que processo similar, de ressaturação e secagem, ocorre durante a obtenção da CCAS em laboratório. Tendo como hipótese que o processo de ressaturação, por provocar perda de argila na amostra, altera a CCAS, objetivou-se obter a CCAS, o índice S e a distribuição dos poros por tamanho a partir de amostras submetidas a ciclos de ressaturação em oposição àquelas não sujeitas a este processo em maiores potenciais mátricos (-2, -4, -6, -8 e -10 kPa). Para tanto, utilizaram-se amostras com estrutura deformada e indeformada, coletadas do horizonte A (textura arenosa) e Btg (textura franco argilo-arenosa) de um Argissolo Acinzentado. Após a obtenção da CCAS, cada amostra foi levada à condição de terra fina seca ao ar e submetida à análise granulométrica e de argila dispersa em água para verificar se houve perda de argila. O delineamento estatístico foi o inteiramente casualizado, com dois métodos de construção da CCAS - com e sem ressaturação - e oito repetições. Concluiu-se que o processo de ressaturação gera perda de argila na amostra, mas não provoca alterações significativas na CCAS nas classes texturais avaliadas; e que as amostras de solo de textura arenosa são mais sensíveis a alterações na distribuição de poros por tamanho quando submetidas à ressaturação. | ABSTRACT Soil-water characteristic curve (SWCC) is an important tool for water management in irrigated agriculture. However, factors such as texture and structure of soils influence SWCC behavior. According to the literature, wetting and drying cycles alter SWCC. A similar process of re-saturation and drying occurs during SWCC obtainment under laboratory conditions. Based on the hypothesis that re-saturation process alters SWCC due to clay loss in the sample, this study aimed to obtain the SWCC, S index, and pore size distribution from samples submitted to re-saturation cycles, as well as from not re-saturated samples but under higher matric potentials (-2, -4, -6, -8, and -10 kPa). For this, disturbed and undisturbed soil samples, collected from the A (sandy texture) and Btg (sandy clay loam texture) horizons of a Argissolo Acizentado, were used. After obtaining SWCC, each air-dried soil sample was submitted to particle size and clay dispersed in water analyses to verify whether the soil lost clay. The experimental design was a completely randomized design with two methods of SWCC constructing (with and without re-saturation) and eight replications. The re-saturation process generates a loss of clay in the sample, not causing significant changes in SWCC considering the assessed textural soil classes. In addition, sandy soil samples are more sensitive to changes in pore size distribution when submitted to re-saturation.

Soil-water characteristic curve (SWCC) is an important tool for water management in irrigated agriculture. However, factors such as texture and structure of soils influence SWCC behavior. According to the literature, wetting and drying cycles alter SWCC. A similar process of re-saturation and drying occurs during SWCC obtainment under laboratory conditions. Based on the hypothesis that re-saturation process alters SWCC due to clay loss in the sample, this study aimed to obtain the SWCC, S index, and pore size distribution from samples submitted to re-saturation cycles, as well as from not re-saturated samples but under higher matric potentials (-2, -4, -6, -8, and -10 kPa). For this, disturbed and undisturbed soil samples, collected from the A (sandy texture) and Btg (sandy clay loam texture) horizons of a Argissolo Acizentado, were used. After obtaining SWCC, each air-dried soil sample was submitted to particle size and clay dispersed in water analyses to verify whether the soil lost clay. The experimental design was a completely randomized design with two methods of SWCC constructing (with and without re-saturation) and eight replications. The re-saturation process generates a loss of clay in the sample, not causing significant changes in SWCC considering the assessed textural soil classes. In addition, sandy soil samples are more sensitive to changes in pore size distribution when submitted to re-saturation.

RESUMO Uma maneira de prevenir a degradação do solo é monitorar a sua qualidade estrutural por meio de atributos e indicadores físicos. Dessa forma, objetivou-se com este trabalho verificar quais parâmetros podem ser utilizados junto com o índice S para a avaliação da qualidade estrutural do solo, após a compactação induzida por tráfego de máquinas agrícolas em um Latossolo Vermelho Distrófico (LVd) e em um Latossolo Vermelho Eutroférrico (LVef), cultivados com milho. O experimento foi conduzido em delineamento de blocos casualizados em parcelas subdivididas, com cinco tratamentos e quatro repetições, para cada classe de solo. Os tratamentos foram: T0= preparo convencional sem compactação adicional; T1, T2 e T3= uma passada do trator de 4, 7 e 10 t, respectivamente; T4= três passadas do trator de 10 t. Foram avaliadas nas camadas de 0-0,10; 0,10-0,20 e 0,20-0,30 m a curva de retenção de água, a densidade, a porosidade do solo e o índice S. Os valores do índice S no LVd foram semelhantes (0,035 a 0,037) no T0, T1 e T2, os quais estiveram relacionados à macroporosidade do solo. Para o LVef, a maioria dos valores do índice S situaram-se acima de 0,035, com exceção do T4, devido aos maiores valores de densidade do solo nesse tratamento. O índice S pode ser utilizado como um parâmetro complementar a altura do milho e a macroporosidade do solo, para a avaliação da qualidade estrutural em LVd. | ABSTRACT One way to prevent soil degradation is to monitor its structural quality through physical attributes and indicators. Thus, the objective of this work was to identify parameters that can be used together with the S-index to assess the soil structural quality of Latosols-Distrophic Red Latosol (DRL) and Eutroferric Red Latosol (ERL)-cultivated with maize after traffic-induced compaction by agricultural machinery. The experiment was conducted in a randomized block design in split-plots, with five treatments and four replications for each soil class. The treatments were: T0 = conventional tillage without additional compaction; T1, T2 and T3 = one pass of a 4, 7 and 10-Mg tractor, respectively; T4 = three passes of a 10-Mg tractor. The water retention curve, density, porosity and S-index of the soil layers 0-0.1, 0.1-0.2 and 0.2-0.3 m were evaluated. The DRL presented similar S-index (0.035 to 0.037) in the T0, T1 and T2, and these S-index were connected to soil macroporosity. Most S-index of the ERL were above 0.035, except for T4 due to its higher soil density. The S-index can be used as a complementary parameter for maize height and soil macroporosity to evaluate the structural quality of DRL.

One way to prevent soil degradation is to monitor its structural quality through physical attributes and indicators. Thus, the objective of this work was to identify parameters that can be used together with the S-index to assess the soil structural quality of Latosols-Distrophic Red Latosol (DRL) and Eutroferric Red Latosol (ERL)-cultivated with maize after traffic-induced compaction by agricultural machinery. The experiment was conducted in a randomized block design in split-plots, with five treatments and four replications for each soil class. The treatments were: T0 = conventional tillage without additional compaction; T1, T2 and T3 = one pass of a 4, 7 and 10-Mg tractor, respectively; T4 = three passes of a 10-Mg tractor. The water retention curve, density, porosity and S-index of the soil layers 0-0.1, 0.1-0.2 and 0.2-0.3 m were evaluated. The DRL presented similar S-index (0.035 to 0.037) in the T0, T1 and T2, and these S-index were connected to soil macroporosity. Most S-index of the ERL were above 0.035, except for T4 due to its higher soil density. The S-index can be used as a complementary parameter for maize height and soil macroporosity to evaluate the structural quality of DRL.

RESUMO O semiárido nordestino enfrenta umas das mais severas secas dos últimos séculos, resultando em reduções severas na produção agrícola. A escassez hídrica na agricultura exige práticas de uso racional e reaproveitamento da água como, por exemplo, a utilização de efluentes de esgoto doméstico . Alternativamente pode-se destacar o uso de esgoto doméstico tratado para irrigação de espécies forrageiras, como a palma. Objetivando avaliar os efeitos da fertirrigação com efluente de esgoto doméstico tratado sob a composição mineral de nutriente em palma forrageira (Opuntia Tuna L. Mill, Orelha-de-elefante Mexicana), foi conduzido um experimento em blocos casualizados em esquema de parcelas subdivididas 3 x (4 + 1), com 4 repetições, sendo três densidades de plantio (66.667,00; 52.282,00 e 33.333,00 plantas ha-1) e duas fontes hídrica associadas a frequência de irrigação com lâmina fixa de 3,5 mm por rega (Frequências de 2,3 dias com água de abastecimento e de 7, 14 e 21 dias com Efluente de Esgoto) e, palma cultivada em sequeiro (testemunha). As análises dos teores nutricionais dos cladódios indicam que houve efeito significativo dos intervalos entre eventos de irrigação apenas para as concentrações de Ca e Mg. Os maiores teores de Ca e Mg foram encontrados com a frequência de irrigação de 2,3 utilizando água de abastecimento. Os macronutrientes em maior quantidade pela palma forrageira foram N e K seguido de Ca, Mg e P. O balanço nutricional indicou excesso de K e P e déficit de N, Ca e Mg, nesta ordem. | ABSTRACT The northeastern semiarid region faces some of the droughts of the last centuries, resulting in serious reductions of agriculture yields. The water scarcity for agricultural requires rational use practices and reuse of water, such as use of domestic effluent sewage. Alternatively, the use of treated domestic sewage effluent utilizing for irrigation of forage species, such as the forage cactus, can be highlighted. In order to evaluate the effects of fertirrigation with treated sewage effluent on mineral nutrient composition of forage cactus (Opuntia Tuna L. Mill, Mexican elephant ear), an experiment was carried out utilizing a split plot 3 x (4 + 1) with a randomized complete block design randomized block and four replications, being three planting density (66,667.00, 52,282.00 and 33,333.00 plants ha-1) and two water sources associated with irrigation frequency of plates fixed on 3.5 mm per irrigation (Frequencies of 2.3 days with water tap and 7, 14 and 21 days with Sewage Effluent) and cactus cultivated in Rainfed agriculturerainfed (control). The analyze of the nutritional contents of cladodes indicated that there was a significant effect of the intervals from irrigation events only for Ca and Mg concentrations. The highest levels of Ca and Mg were found with the irrigation frequency of 2.3 using tap water. The macronutrients concentration in greater quantity by the forage cactus were N e, K followed by, Ca, Mg and P. The nutritional balance indicated excess of K and P and deficiency of N, Ca and Mg, in this order.

The northeastern semiarid region faces some of the droughts of the last centuries, resulting in serious reductions of agriculture yields. The water scarcity for agricultural requires rational use practices and reuse of water, such as use of domestic effluent sewage. Alternatively, the use of treated domestic sewage effluent utilizing for irrigation of forage species, such as the forage cactus, can be highlighted. In order to evaluate the effects of fertirrigation with treated sewage effluent on mineral nutrient composition of forage cactus (Opuntia Tuna L. Mill, Mexican elephant ear), an experiment was carried out utilizing a split plot 3 x (4 + 1) with a randomized complete block design randomized block and four replications, being three planting density (66,667.00, 52,282.00 and 33,333.00 plants ha-1) and two water sources associated with irrigation frequency of plates fixed on 3.5 mm per irrigation (Frequencies of 2.3 days with water tap and 7, 14 and 21 days with Sewage Effluent) and cactus cultivated in Rainfed agriculturerainfed (control). The analyze of the nutritional contents of cladodes indicated that there was a significant effect of the intervals from irrigation events only for Ca and Mg concentrations. The highest levels of Ca and Mg were found with the irrigation frequency of 2.3 using tap water. The macronutrients concentration in greater quantity by the forage cactus were N e, K followed by, Ca, Mg and P. The nutritional balance indicated excess of K and P and deficiency of N, Ca and Mg, in this order.

RESUMO Bacillus spp. têm sido utilizados contra bacterioses que acometem camarão marinho cultivado, proporcionando efeito benéfico sobre o hospedeiro, alterando a comunidade microbiana intestinal e melhorando índices zootécnicos. O objetivo deste trabalho foi avaliar os efeitos de uma dieta suplementada com Bacillus cereus, bactéria com potencial probiótico em pós-larvas de Litopenaeus vannamei cultivados em laboratório. O experimento teve duração de quinze dias e consistiu de seis tratamentos: T1 controle; T2 somente com probiótico; T3 com Vibrio parahaemolyticus (VP); T4 com probiótico e com VP; T5 com V. alginolyticus (VA); e T6 com probiótico e com VA. Foram avaliados a sobrevivência, o ganho de peso, a capacidade de colonização das bactérias probióticas, contagem de patógenos e lesões histopatológicas. Não foi verificada diferença significativa (P=0,05) entre os tratamentos na sobrevivência. Os grupos desafiados com patógenos e sem uso de probióticos foram os que apresentaram menor ganho de peso. Na contagem de Bacillus cereus, houve diferença significativa (P<0,05) entre os tratamentos T2, T4 e T6 , observando-se que o probiótico competiu melhor por espaço e nutrientes quando confrontado com V. parahaemolyticus do que com V. alginolyticus. Os animais alimentados com ração suplementada de probiótico, apresentaram contagem inferior daqueles alimentados sem o uso (P<0,05). Não foram observadas lesões histopatológicas nos órgãos e tecidos dos animais. O Bacillus cereus demonstrou uma alta capacidade de colonizar pós-larvas de camarão, causando uma diminuição significativa de patógenos, provavelmente pela secreção de substâncias antimicrobianas e/ou por exclusão competitiva, justificando seu uso como uma bactéria probiótica. | ABSTRACT Bacillus spp. have been used against diseases caused by bacteria that affect cultured shrimp, providing beneficial effects on the host shrimps by altering their microbial community, and improving zootechnical indexes. The objective of this work was to evaluate the effects of a diet supplemented with Bacillus cereus-a bacterium with probiotic potential-on post-larvae Litopenaeus vannamei shrimps grown in laboratory. The experiment lasted for fifteen days and consisted of six treatments-control (T1), probiotic (T2), Vibrio parahaemolyticus (VP) (T3), probiotic and VP (T4), V. alginolyticus (VA) (T5), and probiotic and VA (T6). The survival rate, weight gain, colonization capacity of the probiotic bacteria, pathogen count, and histopathological lesions were evaluated. There was no significant difference (p=0.05) in survival between treatments. The groups with pathogens and without probiotics presented lower weight gain. The result of the Bacillus cereus count in the treatments T2, T4 and T6 were significantly different (p<0.05), the probiotic bacteria were more aggressive in competing for space and nutrients when compared to V. parahaemolyticus than when compared to V. alginolyticus. Animals fed with the probiotic presented lower counts of these pathogens than those fed without the probiotic (p<0.05). No histopathological lesions were found in the organs and tissues of the shrimps. Bacillus cereus showed a high colonizing capacity in post-larvae shrimps, causing a significant reduction of pathogens, probably by secreting antimicrobial substances and the competitive exclusion, which justifies their use as probiotic bacteria.

Bacillus spp. have been used against diseases caused by bacteria that affect cultured shrimp, providing beneficial effects on the host shrimps by altering their microbial community, and improving zootechnical indexes. The objective of this work was to evaluate the effects of a diet supplemented with Bacillus cereus-a bacterium with probiotic potential-on post-larvae Litopenaeus vannamei shrimps grown in laboratory. The experiment lasted for fifteen days and consisted of six treatments-control (T1), probiotic (T2), Vibrio parahaemolyticus (VP) (T3), probiotic and VP (T4), V. alginolyticus (VA) (T5), and probiotic and VA (T6). The survival rate, weight gain, colonization capacity of the probiotic bacteria, pathogen count, and histopathological lesions were evaluated. There was no significant difference (p=0.05) in survival between treatments. The groups with pathogens and without probiotics presented lower weight gain. The result of the Bacillus cereus count in the treatments T2, T4 and T6 were significantly different (p<0.05), the probiotic bacteria were more aggressive in competing for space and nutrients when compared to V. parahaemolyticus than when compared to V. alginolyticus. Animals fed with the probiotic presented lower counts of these pathogens than those fed without the probiotic (p<0.05). No histopathological lesions were found in the organs and tissues of the shrimps. Bacillus cereus showed a high colonizing capacity in post-larvae shrimps, causing a significant reduction of pathogens, probably by secreting antimicrobial substances and the competitive exclusion, which justifies their use as probiotic bacteria.

ABSTRACT This study aimed to determine the doses of maximum agronomic and economic efficiency as a function of different amounts of roostertree [Calotropis procera (Ait.) R.Br.] biomass added to the soil, that results in the maximum yield of green grains of cowpea in the semi-arid of Rio Grande do Norte state, Brazil. The experiment was conducted at the “Rafael Fernandes” Experimental Farm of the Universidade Federal Rural do Semi-Árido (UFERSA), Alagoinha, RN, from August to November 2013. In the experiment was used a randomized completely block design with 5 replicates. The treatments consisted of 20, 35, 50, and 65 t ha-1 (on a dry matter basis) of roostertree biomass added to the soil. The evaluated characteristics were: number of green pods per m2, productivity and dry mass of green pods, number of green grains per pod, weight of 100 green grains, and dry mass of green grains. The following economic indicators were determined: gross and net incomes, production operational costs, rate of return, and profit margin. The maximum agronomic efficiency of the yield of cowpea green grain was reached at the yield of 3.05 t ha-1, using 61.0 t ha-1 of roostertree biomass in the soil. The maximum economic efficiency yielded a net income of R$ 8,701.42, at the production of 3.02 t ha-1 green grains with 53.57 t ha-1 of roostertree biomass added to the soil. The use of roostertree as a green manure presents technical-economic feasibility in cowpea cultivation for green grains in the semi-arid conditions of Rio Grande do Norte. | RESUMO Este estudo teve como objetivo determinar as doses de eficiência agronômica e econômica máximas em função de diferentes quantidades de biomassa de flor-de-seda [Calotropis procera (Ait.) R.Br.] adicionadas ao solo, que resultem no rendimento máximo de grãos verdes de feijão caupi no semiárido do estado do Rio Grande Norte, Brasil. O experimento foi conduzido na Fazenda Experimental "Rafael Fernandes" da Universidade Federal Rural do Semi-Árido (UFERSA), Alagoinha, RN, no período de agosto a novembro de 2013. No experimento foi usado um delineamento de blocos completos casualizados com cinco repetições. Os tratamentos consistiram de 20, 35, 50 e 65 t ha-1 (em base seca) de biomassa de flor-de-seda adicionada ao solo. As características avaliadas foram: número de vagens verdes por m2, produtividade e massa seca de vagens verdes, número de grãos verdes por vagem, peso de 100 grãos verdes e massa seca de grãos verdes. Os seguintes indicadores econômicos foram determinados: rendas bruta e líquida, custos operacionais de produção, taxa de retorno e índice de lucratividade. A eficiência agronômica máxima do rendimento de grãos verdes de feijão-caupi foi alcançada com o rendimento de 3,05 t ha-1, utilizando-se 61,0 t ha-1 de biomassa de flor-de-seda incorporada ao solo. A eficiência econômica máxima produziu uma renda liquida de R$ 8.701,42, no rendimento de grãos verdes de 3.02 t ha-1 com 53,57 t ha-1 de biomassa de flor-de-seda adicionada ao solo. O uso da flor-de-seda como adubo verde apresenta viabilidade técnico-econômica no cultivo do feijão-caupi para grãos verdes nas condições semiáridas do Rio Grande do Norte.

This study aimed to determine the doses of maximum agronomic and economic efficiency as a function of different amounts of roostertree Calotropis procera (Ait.) R.Br. biomass added to the soil, that results in the maximum yield of green grains of cowpea in the semi-arid of Rio Grande do Norte state, Brazil. The experiment was conducted at the “Rafael Fernandes” Experimental Farm of the Universidade Federal Rural do Semi-Árido (UFERSA), Alagoinha, RN, from August to November 2013. In the experiment was used a randomized completely block design with 5 replicates. The treatments consisted of 20, 35, 50, and 65 t ha-1 (on a dry matter basis) of roostertree biomass added to the soil. The evaluated characteristics were: number of green pods per m2, productivity and dry mass of green pods, number of green grains per pod, weight of 100 green grains, and dry mass of green grains. The following economic indicators were determined: gross and net incomes, production operational costs, rate of return, and profit margin. The maximum agronomic efficiency of the yield of cowpea green grain was reached at the yield of 3.05 t ha-1, using 61.0 t ha-1 of roostertree biomass in the soil. The maximum economic efficiency yielded a net income of R$ 8,701.42, at the production of 3.02 t ha-1 green grains with 53.57 t ha-1 of roostertree biomass added to the soil. The use of roostertree as a green manure presents technical-economic feasibility in cowpea cultivation for green grains in the semi-arid conditions of Rio Grande do Norte.