Mimosa tenuiflora (Willd.) (jurema preta) is a xerophytic species of the shrub-arboreal habit, indicative of secondary succession stage of recovery or progressive, widely disseminated by different caatinga physiognomies of northeastern Brazil, bringing great potential. For the few studies that address their environmental performance, this study aimed to investigate structural and ecological aspects of its population, based data in diameter and height, and characterize the spatial distribution pattern of this species in the study areas. The phytosociological survey was conducted in two areas with 2 and 80 hectares of caatinga at the Experimental Station of Embrapa Semiarid, Petrolina - PE. 10 units were plotted on a random sample measuring 8.0 x 40m, and included all individuals living in diameter at soil level K 3 cm, and measured the total height of the same. Were sampled 283 and 61 individuals in 100 and 80% of plots in areas I and II respectively, inserted mostly in the first diameter classes (3.0 - 6.0 cm and 6.1 - 9.0 cm) and height (2.0 - 3.0 m and 3.1 - 4 m), without trend to standard reverse-J-shape in areas. The spatial distribution, measured by the Payandeh index, reached a value of 2.4 in area I and 7.8 in area II, indicating that the species has a aggregated distribution in both areas. The calculated values for the of Liocourt quotient in areas I and II respectively, got an average of 0.67 and 1.12 with great variation, showing unbalance, despite being in progressive process of natural regeneration.

Sewage sludge, waste from the stations of wastewater treatment, has high contents of organic matter and nutrients and, when stabilized, it presents enormous potential for agricultural use. This study aimed to evaluate the effect of doses of sewage sludge on growth and yield of castor bean. The experiment was conducted in Cambisol, using the cultivar Guarany AL 2002. The treatments in a randomized block design with four replicates, corresponding to a treatment with chemical fertilizer (90 kg ha-1 of P2O5 and 30 kg ha-1 K2O at planting and 40 kg.ha-1 N, 40 days after planting), and five doses of dry sewage sludge (0, 15, 30, 45 and 60 t ha-1). At the end of the cycle, the assessments were made of stem diameter, plant height and productivity. The productivity of seeds and the biometric characteristics of castor bean increased with increasing doses of sewage sludge applied to soil, and the dose from 15 t ha-1 is sufficient for replacement of mineral fertilization of culture without the risk of soil contamination with heavy metals.

The work was carried in a fragment of two hectares of hiperxerofila caatinga that it suffered clearcutting has 30 years and since then recovers without anthropic intervention at the Experimental Station of Embrapa Semiarido, Petrolina, PE. The objective was to evaluate the floristic composition and phytosociological structure, obtaining data to compare with other areas of caatinga (in different stages of succession) and then get subsidies to better understand the characterization of the successional environments of caatinga. The vegetation survey was carried out by the method of the plots, where 10 sample units of 8.0 x 40 m were plotted at random in the area. All individuals with DBH G 3 cm were inventoried, and the BHD are measured and total height of them. We recorded 16 species belonging to 13 genera and 8 families, a total of 436 individuals with AB = 7.28 m²/ha-1, and DA = 1350 ind/ha. The Shannon index of diversity (H') was 1.39 nat.ind.-1 and equability of Pielou (J '), equal to 0.50, both are considered low. The species with highest importance value (VI) and more prominent with respect to all parameters analyzed was Mimosa tenuiflora with 284 individuals distributed in all plots, DR = 65.5%, DoR = 69.6%, VC = 67.5% and VI = 49.8%. Thus, any attempt to characterize the structure of this community, have strong influence of the presence of indicator species of vegetation that is disturbed and the early stage of ecological succession.

The objective of this research was to characterize the nutritional limitations of Jatropha curcas, in addition the effect of the absence of certain nutrients in the growth of the plant. The research was carried in the greenhouse conditions at Agriculture Science Institute of Federal University of Minas Gerais, Brazil. The soil was used dystrophic Yellow Oxisol, colleted in the superficial layer (0-20cm), under cerrado vegetation. The experimental design was totally randomized with 13 treatments and three replications. The treatments were based on the missing element technique (with omission of liming and each one of the macro and micronutrients). The plants without the nutrients P, K and liming showed less growth. The nutrients N, P, K, Ca, Mg e liming affected the shoot of plants. The roots were more affected by absence N, P, Mg and Ca. The results allowed concluding that the macronutrients were more limiting to growth of plant.

The objective of this research was to evaluate the behavior of thermal conductivity in the apparent surface in caatinga predominantly cactus, especially eunapolis [Pilosocereus gounellei (A. Weber ex K. Schum.)]. The study area was the river basin Taperoá, located in the region of Cariris Velhos in the State of Paraíba. Data were used for temperature and heat flux on the surface of vegetated soil. It used the law of heat conduction, who modeling time series of apparent thermal conductivity of the vegetation was made by Fourier methods, linear regression and polynomial. The results are partial, but antagonistic to literature, and they point out that the heat transfer by conduction in the caatinga has significance and should provide support for parameterization and incorporation of vegetation dynamics in the models are, hydrological, environmental or atmospheric circulation.

Substrates containing 0, 10, 20, and 40% (v/v) of urban waste compost were evaluated for the production of Jatropha (Jatropha curcas L.) seedlings in polytube containers. At 40 days after planting, growth characteristics and macro nutrient content in shoot were determined. The urban waste compost added to the substrate promoted increase in Jatropha plants growth. The maximum growth was obtained with the estimated dose of 24% of compost mixed with subsoil material. Increments in the dose of compost caused linear increase in K, Mg, and S shoot content, but N and Ca contents were reduced by dilution, as the shoot dry mass increased more than the uptake of those nutrients.

The aim of this paper was to evaluate the performance of lactating 5/8 cross-breed Holstein/ Zebu cows, and digestibility of diets with different levels (0%; 5.5%; 13.0%; 20.5% and 26.0%) of melon (Cucumis melo L.) fruits in replacement to wheat bran, on dry matter basis. Five cows averaging 380 kg and 10 kg of daily milk production were used. The experiment was conducted in a 5x5 latin square design, including five animals, five experimental periods and five levels of melon fruits addition. The length of each period of evaluation was 14 days (seven for the adaptation of the animals to the diets and seven for data collection). The intake of dry matter (DM) (kg/day, %BW and g/kg0.75), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), total carbohydrates (TCH), ether extract (EE) was unaffected (P>0,05) by the levels of melon fruits (12.52; 3.20; 142.42; 11.62; 1.29; 8.15; 10.21 and 0.41, respectively). Crude protein (CPD) and neutral detergent fiber (NDFD) digestibilities decreased linearly, and the digestibility of non-fiber carbohydrates (NFCD) increased linearly. The estimative for total digestible nutrients (TDN) presented a quadratic response with the addition of increasing levels of melon fruits in the diet. Milk production and fat corrected milk production, averaging 9.09 and 9.78 kg/day respectively, increased linearly with the increment of melon fruits participation in the diets, which points out a possibility for utilization of this co-product to feed dairy cows.

The aim of this research was to investigate the similarity of water quality in space and time in the upland of Salgado watershed, Ceará, Brazil. Multivariate analysis/Cluster Analysis was used for this investigation. Water samples were took in nine stations, spread out along the rivers during March, May, July, August and September, 2005, totalizing 45 samples. The water quality attributes analyzed were: electrical conductivity (EC), chloride (Cl-), sulphate (SO4-2), soluble orthophosphate (OPS), nitrate (NO3-), dissolved oxygen (DO), bicarbonate alkalinity (BA), total coliforms (TC) and turbidity (T). Four homogeneous groups were identified. The water samples collected at rainfall season defined the dissimilarity of group 1 in relation to the others. This group showed the best water quality due to the dilution of salts. Water samples collected during the end of rain-fall season and began of dry season formed group 2. Waters sampled at dry season in stations located down of discharge point of effluents defined group 3. These stations presented the highest concentrations of Cl-, EC, SO4-2 and TC. The values of NO3- and TC defined the similarity of group 4. Although Cl-, SO4-2, DO, and TC influenced the cluster definition, the most important variables were EC and NO3-. The water quality similarity was defined by two factors: punctual pollution and climatic seasonality.

Among the factors that affect the production of coffee distinguishes itself by its high nitrogen demand. The aim of the current paper was to evaluate the productivity of coffee plants, the leaf N level critical stages of grain maturation and export of N, depending on the nitrogen, in order to optimize its recommendation. The experiment was performed in Garanhuns - PE, in a plantation crop. The experimental design was completely used with six treatments (0; 100; 200; 300; 400 and 500 kg ha-1 of N) and four replications. The productivity with the maximum economic efficiency was of 54 bags for hectare of benefited coffee for an application of 196.43 kg ha-1 of N, which represented a decrease of 41.85% in nitrogen. The critical nitrogen ranged from the filling phase to maturity, and their values, from 25.72 to 27.19 g kg-1 and 29.24 to 29.6 g kg-1. For a dose of 328.62 kg ha-1 of N, it was the largest export of this element by the fruit that was 204.31 kg ha-1 of N.

The determination of leaf area is of interest to producers and sectors of research, and techniques should be simple, quick and accurate. This study aimed to compare methods for estimating leaf area of Barbados cherry in orchard. 60 leaves were collected randomly, and after collection, were measurements of leaf area by five methods: squares, linear dimensions, leaf area integrator AM 300, leaf disks and Digital Image Analysis (Scanner). All methods were compared with the reference method (scanner), based on the criterion of determination coefficient of linear regression (R2). The method that is closer to the leaf area of reference was the integrator portable AM 300.