Maniçoba is a native forage species of the semi-arid region of NE Brazil that is widely used in animal rations. The seeds of this plant demonstrate dormancy, with slow and irregular germination, making propagation problematic. The present work examined methods to overcome seed dormancy in three species of maniçoba (Manihot glaziovii, M. pseudoglaziovii, and M. piauhyensis) that were stored in paper and plastic sacks. Seeds derived from different localities (Areia and Barra de Santa Rosa - PB; Araripina and Petrolina - PE) were mixed together, packed into paper or plastic sacks and stored for five months. Each month during the five-month experiment, samples of the seeds were either submitted to stratification, or not, followed by scarification, and then examined for emergence and vigor. Statistical analyses were made of a 2x2x5 factorial scheme (seeds that were and were not treated to overcome dormancy; packing material used; and storage periods) making all of the possible combinations, with four replicates of 25 seeds each. Of the seeds analyzed, those from Barra de Santa Rosa that had been treated to overcome dormancy exhibited the best physiological quality, independent of the packing material used during storage.

The present work aimed to estimate the litterfall rate accumulation in stands of Parkia pendula Benth., Caesalpinia ferrea var. ferrea Mart. ex Tul., Caesalpinia echinatta Lam., Mimosa caesalpiniifolia Benth. and in the native forest in Nísia Floresta National Forest, in the Municipality of Nísia Floresta-RN. The biomass was collected with a metallic frame accomplished in 10 points of each stand in dry and rainy season of 2003. The material was separated in leaves, branches and miscellany fractions, washed, dried at 65ºC for 48 hours and after weighted. Larger biomass accumulation was observed in the Parkia pendula stand with 15.49 Mg.ha-1 and the smallest in Caesalpinia echinatta with 9.52 Mg.ha-1. It was verified in all the stands more leaf biomass production with high amount for Caesalpinia ferrea and Mimosa caesalpiniifolia, accumulating 10.38 and 10.25 Mg.ha-1, respectively. The branches+bark production was larger in the Parkia pendula plot with 4.95 Mg.ha-1 and in the native forest with 3.19 Mg.ha-1. The litterfall accumulation in the pure plantations was larger in the dry period, reaching 33% more than in the rainy season. The cluster analysis classified the forest typologies in two blocks, being the first formed by Caesalpinia ferrea, Mimosa caesalpiniifolia and Parkia pendula, and the second by Caesalpinia echinatta and native forest, with the leaf fraction being the main discriminatory variable.

Knowledge of the speed of infiltration of water into the soil is of fundamental importance to define the methods of soil conservation, planning and design of irrigation systems and drainage. In order to study the speed of infiltration of water into a OxiLatossoil, before the system management tillage applying different empirical models, this work was conducted Centro de Ciências Agrárias, at the Federal University of Alagoas (CECA - UFAL), in order to evaluate the behavior of the equations of Kostiakov, Kostiakov-Lewis and Horton which Were used to estimate the Water infiltration rate in studied soil by using simple the soil under study, using a simple ring to evaluate the infiltration of water in the field. It was then that the system on the equation that more fit the model of the simple ring infiltrometer was to Kostiakov followed the model of Horton.

Despite the mineral fertilization is an important factor for increasing castor beans yield, few researches has been made on this issue, mainly on the use de zinc and copper. In order to evaluate the effects of these elements on the nutritional status of castor bean plant two experiments were carried out in a greenhouse. The substrate for the pot plants was a 5 mm-sieved surface soil (Neossolo Quartzarênico). The experimental design was a completely randomized with three replications. The treatments of first composed of five levels of Zn (0; 2; 4; 6 and 8 mg dm-3) and second experiment were composed of five levels of Cu (0; 1; 2; 3; and 4 mg dm-3) which were applied at the time of planting. One plant of castor bean, cultivar BRS 188 - Paraguaçu, was grown per pot after thinning and was irrigated whenever necessary. At 90, 110, and 130 days after planting were collected the 4 th. leaves of each plant; at the end of the experimental period, all the leaves and stems were collected separately and in any plant material were determined the levels of zinc and copper. The Zn levels used affect the Zn level found in the leaves and stem, and this level is considered adequate. Cu treatments affect the Cu level found in the 4 th. leaves collected at 90 and 130 DAP, however, the Cu level in all periods and all parts of plants is low.

The high incidence of the solar radiation and temperature and the high annual variability of the rainfall during the year in the region of semiarid Paraiba, contribute for the losses of CO2 of the soil. The aim of this paper is to evaluate the microbial activity according the emissions of C-CO2 in a micro basin which is in a process of environmental degradation in Paraíba semiarid, located in the "Fazenda Experimental Bacia Escola, CCA, UFPB" in São João do Cariri, PB, during a translation, in the years of 2003 to 2004. Five points of determination had been choosed in a toposequence where there vas evaluated the microbial activity by the C-CO2 production. In the rainy season the tax of losses of CO2 of the soil diminished independent of the position of determination in the toposequence. In the dry season, when there was some pluviometric precipitation, the tax of edaphic respiration, expressed in terms of losses of CO2 from the soil to the atmosphere, increased with the water availability of the soil.

The use of mine gypsum in reclamation of soils with high levels of exchangeable sodium is viable by its effectiveness, and although this product show others advantages as low price and easy applicability in field. The product is finding in great amount at the Araripe Highland, located across (between) the division of the Ceará and Pernambuco states. The aim of the research work is to evaluate the shoot dry biomass and Ca+2, Mg+2, K+, P and Na+ accumulation on cowpea plants grown in two saline sodic soils recently amended with gypsum. The experiment was carried out in a completely randomized factorial design with three replications, applying 6 levels of gypsum in two soils. The statistical calculations were achieved using the Program SAEG 9.0 and the standard deviations and the averages were compared by the Tukey test at probability P < 0.05. The effects of gypsum levels and the relationships between the variables were analyzed by the Pearson correlation test. Application of gypsum in different levels reduced sodium uptake and increased shoot dry biomass of cowpea plants grown in the Neossolo Flúvico Eutrófico Saline Sodic soil with medium texture. Higher levels of gypsum promoted reduction in phosphorus accumulation on cowpea plants grown in the Neossolo Fluvico Eutrófico saline sodic soil with medium texture.

This work aimed to evaluate the influence of light and temperature on germination of Hyptis suaveolens seeds. The seeds were harvested at Mossoró/RN city and the experiment developed in at the Laboratory of Seed Analysis of the Department of Agriculture of the Federal University of Lavras at Lavras/MG. The treatments was consisted of four temperatures (20ºC, 25ºC, 30ºC and 20-30ºC) and two light conditions (light and darkness). The treatments consisted of 200 seeds, with four repetitions of 50 seeds each, sown on a two Germitest towel paper, displayed inside gerbox, and maintained for 30 days in germination chamber. A completely randomized constituted design with 2x4 factorial design (two light expositions x four temperatures) was used with 4 replicates of 50 seeds. The Scott-Knot¿s Test at 5% of probability was used to compare the obtained averages. There was significant difference in the interaction temperature x shines, in the two variables. It can be concluded that the largest germination of seeds happened in the light presence and in high temperatures. And that the temperatures alternated of 20-30ºC, 30ºC and 25ºC are favorable for germination of seeds of Hyptis suaveolens.

The decrease in pore that are submitted to the certain pressure, causes an increase soil bulk density, causing the compactação process, affecting the ideal development of crop root system. Consequently the present study has as obejective to evaluate the effects of different compaction levels in two soils with differrent textural classes on the yilol of aerial biomass and root of radish. The experiment was carried out in a green house at the, UFRPE, where two samples of soils from 0-20 cm with the following textural classes: sand clay loan (NITOSSOLO) compacted to bulk densities of 1,05; 1,26 and 1,47 g cm-3 and sandy (PLANOSSOLO) compacted to densities of 1,54; 1,76 and 1,98 g cm-3. A severe reduction was observed in the production of bulbs a function of the levels compaction where in the sand clay loan texture there was no development of the bulbs in the density of 1,47 g cm-3, differing from at observed in the sandy texture soil, where the largest density (1,98 g cm-3), showed development of the bulbs. The compaction in subsurface alters the distribution of the root system of he crop along the profile of the soils, without decrease in the production of roots.

Nematodes are abundant metazoans in all ecosystems with some species surviving in extreme conditions. The sand dunes are dynamic systems and are always in a state of successional change in terms of succession and only recently has the distribution and succession of soil animals in coastal dunes been given wider attention. This research focused on to describe the trophic structure of nematode community associated with two stages of a vegetation succession in a coastal moving sand dunes ecosystem in the north shore of the Rio Grande do Norte State. Five sites were classified in two stages of an ecological succession defined as "beach" and "deflation hollows among dunes" where samples of soil, roots and shoots were collected. Nematodes were extracted from the soil by centrifugal flotation procedure and from the roots by this method associated to blender trituration and classified in families and trophic groups according to feeding habits. The structure of nematode fauna was described by maturity index, plant parasite index and modified maturity index and fungal feeders/bacterial feeders and omnivores+predators/bacterial feeders+fungal feeders+plant parasites rates. The ecosystem was characterized by low diversity of families which composed trophic groups, low values of maturity indexes and omnivores+predators/bacterial feeders+fungal feeders+plant parasites ratio and low abundance of dorylaimids. These datas reflected high level of disturbance which this habitat faces.

This experiment had for objective to evaluate some parameters of quality of the bee honey (Apis mellífera L.) produced by IAGRAM and commercialized in the city of Mossoró-RN. For this, 19 honey samples had been collected in the local market, these were analyzed, in the Chemistry Laboratory of the Universidade Federal Rural do Semi-Árido (UFERSA), how much to the color, humidity, total acidity, reducing sugars, apparent sucrose and diastase activity. It was utilized districted statistics for analysis of date, with shunting line standard, reliable interval and distribution of frequency. The honeys sample presented the colors clearly extra amber (5,2%), amber (5,2%) and dark amber (89,4%). The honey samples presented normal standard established for the Brazilian Legislation as humidity percentage (14,3 18.6%) and reducing sugars (66,9 75.0%). About 5,2% and 42% of the analyzed honey samples, not presented, respectively, apparent sucrose content and total acidity, as the standard established for commercialization as floral honey. The diastase activity was remained inside of the quality standard.