Stachytarpheta coccinea Schauer (Verbenaceae) is recorded for the first time to the Rio Grande do Norte State, Brazilian Northeast. This species was found in Caatinga vegetation especially at the region Western of the State. Description, geographic distribution and illustrations to the species are presented.

This research focused on to test the reaction of cultivars and introductions of watermelon (Citrullus lanatus) and varieties of cotton (Gossypium hirsutum) to Rotylenchulus reniformis. Two experiments were carried out independently with treatments arranged in a completely randomized design. In the first one 4 cultivars ('Crimson Sweet', 'Charleston Gray', 'Sugar Baby' and 'Omaru Yamato') and 4 introductions ('MO-1 to MO-4') of watermelon were tested and in the second one 9 varieties of cotton ('BRS Ipê', 'BRS Rubi', 'BRS Safira', 'BRS 200 Marrom', 'IAC 23', 'Auburn 2', 'Deltapine 16', 'BRS 187-8H' and 'Deltapine 61'). Each treatment consisted of one genotype with 4 replicates witch consisted of one plant grown in a mixture of sterilized and naturally infested soil by 2.784 and 3.016 vermiform specimens in the first and second experiment, respectively. Cultivars and introductions of watermelon reacted as poor hosts while varieties of cotton reacted as good hosts of R. reniformis.

The State of Rio Grande do Norte is the largest exporter of muskmelons in Brazil and producers, in general, use irrigation water of different levels of salinity (ECw). However, in the region there is little information available on the effect of salinity of the water on the absorption of nutrients by the melon crop. Therefore, objective of this research was to study the extraction and accumulation of nutrients to in two varieties of melon (Orange Flesh and Goldex), irrigated with water of low (0.80 dS m-1) and high (3.02 dS m-1) salinity. The study was conducted from October to December, 2003, in Red Latosol of medium texture at the Fazenda Santa Julia (Latitude 5o 02' 0,0" S, Longitude 37o 22" 33,6" WGr.), in the municipality of Mossoró, RN, Brazil. The experimental design adapted was in random blocks with four replications. Largest accumulation of dry matter was found in the fruit in the aerial part after 63 days of sowing, representing 59.17% and 74.53 (Orange Flesh and Goldex) in the condition of low electrical conductivity (0.80 dS m-1) and 70.50 and 67.27% in cultivars Orange Flesh and Goldex, respectively, for high electrical conductivity (3.02 dS m-1). The application of saline water (3.02 dS m-1) reduces the content of potassium in cultivar Goldex by 39%.

The study area involves the territory limit of the Boa Vista municipality, 446.30 km2, situated in the Cariris Velhos homogeneous micro region, semi-arid region of the Paraiba State. The present work had as objective the elaboration of thematic maps of the space-time evolution of vegetal covering classes, period 1987/2004, of the Boa Vista municipality using TM/LANDSAT-5 satellite's digital images and photo interpretation techniques and images digital processing, available in the SPRING v. 4.2 software, beyond field work. The maps were elaboration be using the segment images supervised classification method and edited by SCARTA module. The results had indicated that the covering vegetal class most conserving, dense to semi dense, suffered reduction of 13.93% between 1987 and 2004; in this period the percent of areas with semi-dense to semi-sparse class was practically steady, diminishing only 0.87%; besides, the more critical covering class (semi-sparse to sparse and sparse + exposed soil) had increased 9.02% and 5.73%, respectively. These results are related with the raised use of lands for cattle the extensive one, as well as for the lack of income of the agricultural population that without option uses the vegetation in the firewood form.

The semiarid is characterized for presenting precipitations concentrated in short period of time, form that to most of the year the ground are displayed the strong insolation and to the raised hídrico deficit. On the other hand, the estacional variation of the climate affects the water content of the ground and as consequence the biological activity and the losses of C, mineral N and C-CO2.The purpose of this research was to analyze the losses of C, mineral N and C-CO2 of the ground in a microbasin, that passes for a process of environmental degradation, located in the Fazenda Experimental Bacia Escola/CCA/UFPB in São João do Cariri - PB, during the period of a translation, of the years of 2003 and 2004. It was defined a toposequence and chosen points of determination for the evaluation of the reserves of carbon, mineral nitrogen and microbic activity by means of the C-CO2 production. The biggest amounts of C had been verified in the areas of pediment and the minors in the area of side slopes; The amounts of mineral N was not influenced by the position of the ground in the toposeqüência; The biggest liberation of C-CO2 happened in the areas of pediment followed by the flood plain and half hillside, places with the biggest amount of of water in the soil.

This work was carried out from october to december, 2005, in Agropolo Assu-Mossoró region, RN, Brazil, with the objective of evaluating the effect of nitrogen and potassium doses on fertilization efficiency of melon crop. Three simultaneous trials were performed in adjacent areas, each one receiving a different water amount (L1=0.76NTI, L2=0.9NTI and L3=1.04NTI). Experimental design was a randomized blocks in a factorial scheme with three replications. Treatments consisted of combination of three doses of both nitrogen (N1=42, N2=84 and N3=126 kg ha-1) and potassium (K1=106, K2=212 and K3=322 kg ha-1), plus two additional treatments (N2K0 e N0K2), applied only with intermediary water amount. N2 e K2 was the levels recommended for melon. Indexes of agronomic efficiency of fertirrigation were determined for nitrogen, potassium and irrigation depths. Agronomic efficiency was influenced by N and K doses, irrigation depths and by factor interaction. Treatments L3N1K1 (305.57 kg kg-1) and L3N2K1 (132.63 kg kg-1) presented higher efficiencies for fertirrigation with nitrogen and potassium, respectively.

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.

With the objective of evaluate the changes in the physical-chemistry characteristics of the soil cultivated with bell pepper, fish effluent, natural phosphate and cow manure, an experiment was accomplished in the vegetable garden of the Universidade Federal Rural do Semi-árido-UFERSA. A randomized complete block design in split plot scheme with two replications within of block. In the plot the water types were designated (well water and fish effluent), in the subplot the treatments of the factorial 2x2, resulting from the combination of two match levels (with and without natural phosphate) with two cow manure levels (with and without cow manure), and in the sub-plot the evaluation times (before and after the bell pepper culture). Soil samples were collected before and after the bell pepper cultivation of 0-20 cm depth. After the assembly of the overhead irrigation and distribution of the treatments, it was collected of each plot a soil sample for the accomplishment of the physiochemical analyses. To verify the alterations happened in the soil with the treatments, after the last crop, to the 100 days after culture. Two sources of irrigation waters were used. The first originating from of a tubular well. And second of a Orecochomis niloticus cultivation. The appraised characteristics in the soil before and after the cultivation they were: chemical analysis of the soil (nitrogen, match, organic matter).

Using data from basic speeds of infiltration (VBI), obtained in soils of Coastal Tabuleiros the city of Mal. Deodoro, for aluminum and speed of infiltration for projects (VIP), calculated using the techniques Fashion (Mo), Medium Harmonic (MH), Geometric (MG), simple arithmetic (MAS), Quadrática (MQ), Cúbica ( MC) and Biquadrática (MB), in addition to the Median (Md), was carried out studies on water-saving irrigation by sprinkling compared to the volumes obtained on the basis of these techniques and there is the potential for the runoff. It was the conclusion that the economy of water increased in the following order of technical definition of VIP: MB, MC, MQ, BUT, MG, Md, MH, Mo. Thus, the technical definition of the VIP which saves more water for irrigation is the Fashion.