The replacement of the natural systems by sugar cane leads to fundamental alterations in soil carbon and nitrogen stocks and consequently in the global cycle of these elements. This study was conducted in the municipality of Capim, Paraiba State, and the objective was to evaluate carbon and nitrogen stocks in soils of a natural forest in comparison to sugar cane with and without vinasse. The studied soil was a Dystrophic Gray Argisol. The soil samplings were performed in five replicates (five profiles) at the depths of 0-5, 5-10, 10- 20 e 20-40 cm. The systems were selected namely, native forest; sugar cane with vinasse and cane sugar with- out vinasse. The carbon and nitrogen contents and stocks decrease after the change of native forest to plant sugar cane. In general, there is not significant difference in the carbon and nitrogen contents and stocks be- tween the environments of cane sugar. The systems of cane sugar with and without vinasse are functioning as C -CO2 emitter when compared with the native forest.

Our objective was to evaluate the chemical composit ion and in vitro digestibility of dry matter of hydrolyzed sugar cane in different storage times . We conducted the trial in the Forage Sector at UN IFENAS, campus of Alfenas (MG) in 2010. The data were analy zed as completely randomized design in factorial sc heme 2 (sugar cane without lime and hydrolyzed with 1.0% of lime, basis of fresh matter) x 6 (six times of storage: 0, 24, 48, 72, 96 and 120 hours), with three replicate s. The sugar cane stored without lime showed lower dry mat- ter (DM), crude protein, neutral detergent fiber an d acid detergent fiber contents compared to hydroly zed sugar cane. However, the hydrolyzed sugar cane showed hig her contents of organic matter (OM) and total diges tible nutrients. We reported higher in vitro digestibility of DM and OM when the sugar cane was not hydrolyzed. This can be explaining by better chemical compositi on of sugar cane without lime. The storage of sugar cane without lime shows results more interesting because the chemical composition and digestibility is bett er than hydrolyzed sugar cane. So, we not recommended using lime on the sugar cane. Moreover, the sugar cane w ith- out lime can be stored until 96 hours after cut.

Ziziphus joazeiro es un árbol fructífero endémico del bioma Caatinga, situada en la región semi- árida del noreste brasileño. No obstante su amplia importancia económica y ecológica, las informaciones sobre la comunidad de insectos asociados a esa especie vegetal son insuficientes. Así, el objetivo de este trabajo fue realizar un levantamiento de los insectos asociados a las flores de Z. joazeiro y observar el horario donde ocurre el mayor número de visitas. El estudio fue realizado dentro del bosque de Z. joazeiro ubicado en el Campus de la “Universidade Federal Rural do Semi-Árido”, municipio de Mossoró, Estado de Rio Grande do Norte, Brasil. El muestreo fue efectuado durante el pico de floración entre los meses de noviembre y diciembre de 2010. Una vez por semana se observaron cuatro árboles de Z. joazeiro, al acaso, desde las 05:00 hasta las 17:00 horas. Cada árbol fue observado durante 15 minutos y los insectos capturados con red entomológica. Los insectos asociados a Z. joazeiro pertenecen al orden Hymenoptera, representados por las familias Apidae, Vespidae, Crabronidae y Leucospidae y, al orden Diptera, con las familias Syrphidae, Muscidae, Calliphoridae, Tabanidae, Dolichopodidae, Stratiomydae, Otitidae y Micropezidae. De todas las familias, Apidae, específicamente, Apis mellifera L., fue la que tuvo mayor frecuencia de visitas, con 48%, seguidas por Vespidae (31.4%) y Syrphidae (9%). En general, los insectos visitaron las flores de Z. joazeiro en mayor frecuencia durante el período matutino, con picos entre las 7:00 y 8:00 horas y entre las 11:00 y las 12:00 horas del día.

Chicory is a vegetable Amazon unconventional flavor that has attracted the attention of researchers for its great versatility, which makes it a promising vegetable. However, jobs are scarce in the literature on cultivation techniques for the species. This study aimed to evaluate the effect of pruning tassel floral and different spacing, the yield on Amazon chicory. Three different spacings: E1 = 0.15 x 0.15 m, with 44 plants m2, E2 = 0.20 x 0.20 m, with 25 plants m2, and E3 = 0.25 x 0.25 m, with 16 plants m2, with and without pruning floral tassel. The experiment was conducted in a randomized block design in a split plot design 3 x 2, with six replications. The characteristics evaluated were: number of leaves, fresh weight and dry weight of shoots, number of tassel floral tassel floral fresh weight, yield (kg m-2), and leaf area index (LAI). The largest production of chicory Amazon was obtained in plants grown at a spacing of 0.25 x 0.25 m subjected to pruning floral tassel. The highest yield for Amazon chicory was obtained in plants grown at a spacing of 0.15 x 0.15 m submitted pruning floral tassel.

In the search for more sustainable energy sources, it has been invested in renewable energy sources like the biodiesel. However, for certification sustainable it is necessary that the energy generated by the biofuel is greater than the energy required for the entire production process. In this context, nitrogen fertilization has been a challenge because are large energy expenditures to obtain it, then, the use of alternative sources of nitrogen in agriculture may enable the environmentally friendly biodiesel. Thus, the objective this study was to evaluate the influence of the use of treated domestic sewage in the production of sunflower. The statistical design used was randomized blocks in split plots with four replications. In the plots, we evaluated the effect of two types of irrigation water; plots were distributed five irrigation, 0.25, 0.50, 0.75, 1.00 and 1.25 of the evaporation of class “A” PAN. In subsubplots, we evaluated the effect of four doses of nitrogen fertilization 25, 50, 75 and 100 kg ha-1. The more positive energy balance of 1:1,30 and 1:1,36 was obtained with irrigation of 222.48 mm and nitrogen levels of 50 and 25 kg ha-1, irrigated with well water and sewage, respectively.

The use of manure as a nutrient source is of fundam ental importance in the restoration and maintenance of soil fertility, especially in semiar id regions. The purpose of this study was to evalua te the nutri- ent release during decomposition of different manur es in the Paraíba semiarid region. The experiment w as con- ducted at the Experimental Field belonging Embrapa, in Patos/PB. The treatments were arranged in block s with split plot with four replications using a factorial arrangement 4 x 2 x 6, referring to four types of manure (donkey, cow, goat and sheep), two forms of deposit ion (surface soil and buried 10 cm deep) and six sa mpling times for assessment (30, 60, 90, 120, 150 and 180 days after the experiment). Were determined the con centra- tions of N, P, K, Ca and Mg. The N in goat and shee p manure were higher than 50% of the donkey and cat tle manure and also showed the highest levels of calciu m and magnesium. The sheep and cattle manure showed the highest levels of phosphorus and potassium, res pectively. The goat and sheep manure showed the hig hest levels of N, Ca and Mg. The release of nutrients fr om manure spread on the soil surface and incubated showed little variation in the initial phase of the experi mental period. Increases in soil water content prov ided higher activity of the microbial community, with more inte nse release of nutrients in the manure treatments were in- cubated in soil.

The sustainable management of savanna reduces the devastation of semiarid and aims based agricultural guided by systematic principles of agroecology. In that connection we evaluated the effects of cropping systems and management of savanna through the analysis of chemical indicators of soil quality in agricultural production in Apodi, RN. . The systems were evaluated: 1 - management area of savanna with 5 (five) years (MAS5), 2 - management area of savanna with 7 (seven) years (MAS7), 3 - conventional system (CSA) and 4 - native forest (NF). The chemical analysis revealed that the management of savanna for five to seven years is a beneficial way contributed to conservation of soil.

Studies on the floristic diversity including climbers and also research directed to survey of these species are rare in Northeastern Brazil. With the aim of contributing to the knowledge of this component in the Northeast region and provide data on the flora of Rio Grande do Norte, a floristic study was carried out in a fragment of the Semideciduous Seasonal Forest in the municipality of Parnamirim and an identification key was created for the species. 20 species were registered belonging to 19 genera and 11 families. Eight of these species are new records for the state. The richest families in species were Fabaceae (05), Dilleniaceae (03), Bignoniaceae (02), Convolvulaceae (02) and Passifloraceae (02). The sum of the representatives of these families corresponded to 60% of the total number of species recorded. Comparative analysis suggests that studies be conducted focusing the diversity of climbing in northeastern Brazil, especially because these indicate the state of conservation of forests.

This paper aimed to investigate the factors of influencing milk consumers of Natal city, state of Rio Grande do Norte, in their buying decision. The methodology was a descriptive and exploratory type Survey, with 385 questionnaires applied on the four geographical areas of Natal city. Sample size was found according to the county inhabitant number, and survey was applied through questionnaire applied at randomized suburbs, streets and houses from four geographical city zones. The statistical analyses were: descriptive analysis, comparison test of means and Cluster analysis. Results were that milk quality had high average, in contrast with the price and brand which had the lowest ones. Milk quality and image of the store were the factors most stable for the consumer make its purchase decision, while price and brand were those of least importance. Comparisons among variables showed significance (P<0,05) except for price importance, visual appearance, no product on the market shelves, easy of buying and product status. As conclusion, milk quality is the main factor for consumers to make a decision to purchase milk, whereas price and brand were of least importance.

The fertilization of the castor bean plant (Ricinus communis L.) is few studies in the Northeast, where soils are generally poor in nitrogen (N) and phosphorus (P). This work aimed to define the doses of N and P2O5 associated with maximum economic production of castor beans cultivar BRS Energia and critical levels of N and P in castor bean leaf and the critical level of P available in an Oxisols. The experimental design was a randomized block in factorial 4 x 4 with four replicates, combining four N rates (0, 45, 70 and 120 kg ha-1) with four P2O5 rates (0, 30, 60 and 120 kg ha-1). The castor bean plant was planted at a spacing of 0,90 x 0,50 m under rainfed conditions with supplementary irrigation. At the end of the experiment, was evaluated the overall productivity and productivity racemes primary, secondary and other. The higher net income was estimated to productivity of 2.304 kg ha-1 grain, obtained by applying the doses of 120 kg ha-1 of N + 120 kg ha-1 of P2O5. The critical levels of N and P in the leaf were 37,5 g kg-1 and 2,4 g kg-1, respectively, and the critical level of available P in soil by Mehlich-1 extractor was 7,0 mg dm-3.