A Caatinga vegetation was submitted to various grazing intensities (GI) by steers (1981-84) to verify their effect on ligneous stratum degradation. The study involved four GI: Heavy (1 steer/6.7 ha); Moderate (1 steer/10.0 ha); Light (1 steer/13.3 ha); Exclosure (no grazing). Areas under grazing varied from 40 to 80 ha, whereas exclosure had 20 ha. The research had two replications, occupying a total area of 400 ha. Data of woody species new plants density (NP) were determined annually in 1 m2 plots, and data of shrubs and trees density were determined by Point-Centered Quarter Method in 1982 and in 1984. NP density (Mean = 3.38 plants/m2) was neither affected by GI, nor by years, although it was highest in 1984 (3.83 plants/m2), the rainiest year. Taking into account the eight areas, there was linear relation (P<0.01) between 1982 and 1984 tree densities. There was linear relation between tree density and density of tree species in shrub stages in 1982, but not in 1984, because the drought probably affected shrubs but not trees. There was, for some tree and shrub species, linear relation between adult plant and NP densities. This fact occurred more in 1982. There was in 1983 a very high germination of the tree Tabebuia spongiosa (22.14 seedlings/m2), there being a linear relation (P<0.01) between NP and tree density.

Hydroponics is a method of culture which offers producers a larger number of cycles throughout the year, and value aggregated to vegetables. Empiricism, however, in the use of nutritive solutions, and the non-adoption of harvest times at which lower nitrate content can be achieved, may lead to a drop in produce quality due to the accumulation of nitrate. An experiment using a hydroponic method, the NFT, was conducted in the spring of 2003, in Jaboticabal, SP, aimed at evaluating nitrogen concentration in the nutritive solution (60,8; 121,6; 182,5; 243,5 mg L-1), rocket cultivars (Cultivada, Folha Larga and Selvática) and harvest time factors (7 a.m., noon and 5 p.m.) in nitrate content of rocket. The experiment was carried out in a randomized blocks design and a 4 x 3 x 3 factorial design, with four replications. For nitrogen concentration in the nutritive solution of 93 mg L-1, which showed higher MFPA, nitrate content was 598,4 mg kg-1 NO3 - fresh matter for rocket harvested at 7 a.m.

This work was carried out under greenhouse conditions to evaluate the growth and the mineral nutrition of the stylosanthes in response to levels of sugar-cane bagasse used as substrate for multiplication of arbuscular mycorrhizal fungi, and tested as inoculant. Randomized blocks design was used in a 4 x 3 factorial, being four levels of the sugar-cane bagasse (5, 10, 15 and 20% of the volume of the pot of 6 L) and three microbiology treatments (Control; Native Inoculum and Glomus clarum), with four repetitions. The shoot were harvested 60 days after seeding and it was analyzed the dry matter yield (DM) and root (DMR), the accumulations of crude protein (CP), P, K, Ca, Mg and S; the mycorrhizal colonization, density of spores and number of nodules. The sugar-cane bagasse promote lineal increment in the production of DM independent of the mycorrhizal inoculation. In of DMR, there is interaction between levels of sugar-cane bagasse and microbiology treatments. The inoculation with the native inoculum increases the accumulated amounts of P, K, Ca, Mg and S; the density of spores and number of nodules, the same not happening for the Glomus clarum. Crude protein and mycorrhizal colonization were not influenced by the treatments.

The effect of tannery sludge on the cellulose decomposition was studied in the laboratory as a dose-response experiment. Cellulose decomposition rates were determined by the weight loss from cellulose filter disks buried in soil samples. The amount of tannery sludge used were 0, 11, 22, 44, 88 and 172 Mg ha-1, and, corresponded, respectively, to incorporation of 250, 500, 1,000, 2,000 and 4,000 mg Cr3+ kg-1 of soil. The cellulose filter disks presented different degrees of decomposition with application of tannery sludge. After 30 days of incubation the cellulose decomposition rate, corresponding to application of 11, 22 and 44 Mg ha-1 were higher than soil untreated (control), respectively 5%, 20% and 10%, but the difference was only significant for the 22 Mg ha-1. There was a significant decrease of 50% in the cellulose decomposition, compared to untreated soil (control), with application of 172 Mg ha-1 of tannery sludge. This study has demonstrated that cellulolytic activities are susceptible to be inhibited by high rates of tannery sludge. When applied to low amounts, tannery sludge did not affect cellulose decomposition by the soil microflora.

The present work, Brachiária decumbens Stapf., to the application of lime, nitrogen and zinc in the quality of dry matter to evaluate residual the reply of the during four cuts. For this, an experiment was installed in the UNESP/FEIS, Selvíria-MS, a distrofic Red Latosol (october/1996 may/1997). The experimental design was blocks randomized, in factorial project 3x3x2, with 4 repetitions. The treatments had been composites for three rates of nitrogen: 0; 50 and 100kg ha-1, three rates of lime: 0; 267 and 556 kg ha-1 and two rates of zinc (0 and 5 kg ha-1), applied in the first year and reapplied in as the year, except the lime. In as the year of experimentation, one became fullfilled three cuts in the grass to the 10 cm of the soil, with intervals of 49 days, for the evaluation of the text of crude protein, coefficient of digestibility "in situ" of the dry matter and content neutral detergent fiber. The crude protein, increased with the fertilization nitrogen in all the cuts of the grass, however, the effect of the application of Zn and limestone, in the increment of the crude protein, was restricted only in as the cut. In as the cut it had positive interaction of N and Zn. The digestibility coefficient was increased with the application of the limestone only in the third cut, while in as cut had this increase occurred only with use of the biggest dose of N. The nitrogen fertilization diminished the neutral detergent fiber in the first cut of the grass, and increased in excessively the cuts. While, the zinc and lime application did not affect the neutral detergent fiber in the three cuts of the grass.

In environmental studies is important to know the adsorption process of heavy metals in clay minerals, since they are able to immobilize these metals. Knowing the cations adsorption is influenced for several factors, the objective of this research was to study the copper adsorption process by bentonite clay and to evaluate the electrolyte type and pH influence on this process. In order to quantify the adsorbed copper, 2 g of bentonite clay were equilibrated for 24 hours with 20 mL of a NaNO3 (0,01 mol L-1) solution and with 20 mL of water containing different quantities of copper (5, 10, 20, 40, 60, 80, 100,120 mg L-1) as background solutions of pH values 4 and 6. Langmuir's adsorption equation in its linearized form was applied and the values of the maximum capacity and those of the constant related to the bonding energy were obtained. Langmuir isotherms presented two distinct adsorption regions at both pH 4 and pH 6, showing that the adsorptive phenomenon occurs in two distinct stages. The adsorption of copper depends on pH and ionic strength and it increased with an increase in pH and decreased slightly with an increase in ionic strength. The maximum capacity of adsorption and the bonding energy varied with the pH, with electrolyte used and with the adsorption regions.

The osmotic conditioning is a technique that uses inert chemically substances with the aim to begin the essential biochemical processes to embryo growth without there is seedling protrusion. This revision refer the several factors that interfere in the osmotic conditioning technique, as well as the use of chemistries, temperature, conditioning period, drying, storage and seeds revigoration. Other aspects as reduced time to obtain seedling, dormance overcome and seed revigoration.

The objective of the present work was to study the characteristics biometrics of the fruit and the effect of the physical and chemical scarification in the germination of seeds of Caesalpinia ferrea Mart. ex Tul. Ripe fruits were collected in August of 2007 of existent trees in the campus of the Rural Federal University of the Semi-arid, Mossoró- RN. The evaluations were carried at the Laboratory of Analysis of Seeds of the Department of Vegetable Sciences of UFERSA. The germination test was constituted of witness and 4 treatments (types of common vinegar: vinegar of alcohol, vinegar of red wine and vinegar of white wine) and hot water to 65ºC, with 4 repetitions of 50 seeds. The sowing was in containers plastic with dimensions of 32.5 x 24 x 4 cm (length, width and depth). The used substrates were sand washed sterilized previously and being irrigated with water distilled. The appraised characteristics were: mass of the fresh matter and matter dries of the seedling, germination percentage and index of emergency velocity. The immersion of the seeds in vinegar of white wine favors the germination, the index of germination velocity and the accumulation of fresh and dry matter of the juca seedlings.

With the purpose of to evaluate the milk composition of cows fed with sugar cane whose crude protein had been corrected with soybean meal and different urea levels and ammonia sulphate, twelve dairy Holstein pure breed and crossbreed cows maintained in tie stall fed ad libitum twice a day had been used. The forage:concentrated relationship at the beginning of experiment was 55:45%, corresponding 1kg of intent ration for each 2kg of milk produced. The animals were distributed in three Latin squares 4x4, according to lactation period. The duration of each period was 17 days, being the first 10 days of adaptation and seven days to data collection. The experiment was composed of four treatments: sugar-cane with soy bean meal and sugar-cane with 0.4; 0.8 and 1.2% of the mixture urea and ammonia sulphate (9:1). No difference was found among the diets for milk production with and without correction to 3.5% fat, neither for milk composition and serum urea nitrogen (SUN) when the diet with soy meal based concentrate was compared with the diets with different urea levels. The soy meal can be used for protein correction the sugar-cane. For correction using the mixture urea and ammonia sulfate (9:1) the level of 1.2% is recommended.

The current model of economic development is based on a predatory and exculpatory vision, which discloses a way of being inhuman. Implying in changes of perception, thoughts and values, it has seen, that the form as the nature is explored in accordance with varies the ambient perception of the community or group. This work objectified to analyze the perception of Juazeirinho/PB agricultural communities referring the extinction of biodiversity of caatinga, aiming at to delineate sensitization strategies that make possible the valuation of this biome. The work portrays a carried through participant research with the communities Escurinha and Mendonça. For the collection of data direct comment was used, with visits to the communities, dynamics, half-structuralized interview and accomplishment of meeting. According to community some vegetal and animal species are disappearing. Between the animals they are cited: corduniz (Nothura sp), gato do mato (Felisa tigrina), gato maracajá (Felis wildi), mocó (Kerodon rupestris), preá (Gálea sprixii), Tejo (Família Teiidae), tatu peba (Euphractus sexcinctus), tatu verdadeiro (Dasypus novmcinctus) e o guaxinim (Procyon camcrivorus).Between vegetables they had been cited: Aveloz (Euphorbia gimnoclada), Imbuzeiro (Spondias tuberosa), Aroeira (Myracroduom unrudeuva), Caatingueira (Caesalpinia pyramidali), Baraúna (Schnopsis brasiliensis), Quixabeira (Bumelia sertorum), Mufumbo (Combretum leprosum). We can verify that it is necessary to promote changes in the ambient perception of the studied communities, thus allowing, to awake for problematic ambient, to point and to search solutions, that take the valuation of local biodiversity.