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The inadequacy of sewage systems and water shortages in semi-arid Northeast is encouraging the reuse of water in the production of agricultural crops. This study aimed to analyze the effect of treated do- mestic sewage in the initial development of three melon cultivars in Mossoró-RN. The experiment was mounted on a split-plot in randomized blocks with plots cultivars of melon (Yellow Tikal, Cantaloupe type Harper and Gália) and the split-plots the proportions of water supply and domestic sewage (T1 - 100% water supply T2 - 50% of water supply and 50% of domestic sewage, T3 - 25% of water supply and 75% of domestic sewage and T4 - 100% domestic sewage) in three replicates. In the experimental period were analyzed for physico-chemical and microbiological characteristics of sewage and water supply. At 20 days after sowing was measured plant height, stem length, root length and stem diameter. The results showed that the fertirrigation of melon cultivars with domestic sewage minimizes the effect of water scarcity in semiarid. The development of cultivar Gália seedlings was not affected by application of primary domestic sewage. The T2 and T4 were the most suitable for the production of cultivar Gália seedlings.

For proposition of the better recovery practice is necessary to identify the main characteristics of index fingers soil of environmental degradation. For so much, it should seize upon chemical, physical and biological analyses. Thus, the goal of this work was to study some chemical indicators of environmental degradation in soils terms of semiarid. The soils were collected in the pilot's area JICA Project located in the municipal district of Pedro Avelino-RN, the choice of the area was due to your desertification degree. The analyses were accomplished in Soil, Plant and Water Analyses Laboratory of the University Semi-arid Rural Federal. The samples were collected in the layers of 5, 10, 20, 30 and 50 cm. The accomplished chemical analyses were: pH in water (1:2,5); Electric Conductivity (CE) in the extract 1:5; Ca+2,Mg+2, Na+ and K+ exchangeable, and P available. By the results, it verified that pH and CE increased with the depth, with regard to the contents of In the Na+ in the soil there was variation with the increase of the depth. To the thwart of the majority of the analyzed elements the K+ tended to decrease your content in the soil with the increase of the depth, The sodium elevated contents should be carried in consideration for the implantation of the recovery project, using itself preferentially resistant plants of sodicity.

In many areas irrigated of the world, water supply of good quality not be enough for the maintenance of the irrigated agriculture, or your cost be elevated, seeking itself alternative with water use of the underground or even of drainage. Generally, these waters are not of good quality and they need to be well managed to avoid the degradation of the soils and damages to the plants. This work objectified evaluate the composition of lixiviate in four soils of Rio Grande do Norte, irrigated with waters of increasing levels of electric conductivity (EC) and sodium adsorption relation (SAR). This work aims to evaluate Assu/Mossoró, RN, agricultural production center soil degradation under irrigation with increasing electrical conductivity (EC) levels, and sodium adsorption rates (RAS), when cultivated with cantaloupe. The work was conducted in a greenhouse at the Environmental Sciences Department of Semi-Arid Rural Federal University. Four soil types, traditionally used for cantaloupe production, were used and irrigated with solutions corresponding to eight EC (EC = 100, 250, 500, 750, 1.250, 1.750, 2.250 and 3.000 ¿S/cm) and two SAR (SAR = 4 and 12) levels, as salinity treatments, corresponding to the irrigation waters used in the Northeast, with low sodification risk, especially in the studied area. So the experiment was a factorial arrangement of 4 x 8 x 2 (four soils, eight EC and two SAR), with three replicates, on a randomized block design. They were evaluated pH and EC, as well as cations and anions soluble of each lixiviate collected of the 10 days after transplanted of the dumb. The use of leaching solutions promoted salt leaching in four studied soils, mainly at Cambissolo and Neossolo.The increase in the concentration of the percolates solutions promoted larger losses of salts, which were crescent with the time of leachate.

The burning of the sugar cane for occasion of the harvest causes an expressive volatilization of the sulfur contained in the vegetable material, worsening possible deficiencies of this nutritious the short and average term. The goal of this research was to evaluate and to determine the critical levels of sulfur in soils using the mineral gypsium as sulfur source. They were installed four field rehearsals in different class texturais soils. In all rehearsals the experimental delineation employee was blocks at random. The treatments in each rehearsal they constituted of the combination of five doses of mineral gypsium and three chemical extractors, with three repetitions. They evaluated the treatments at thirty days after the application of the sulfur doses in the depths 0-0,2m of sampling. The sulfur doses were defined from need to calagem, for the layer 0,4-0,6 m of depth. With the results of recovered sulfur and production of the sugar cane, they were certain the critical levels of sulfur in the soil. The ammonium acetate extractor in acetic acid extracted more sulfur in loamy soils, of low values of P-rem and with larger contents of organic matter, while the calcium chloride extractor introduced sulfur extraction smaller power, at the same terms. Already the calcium phosphate, contend match and in the presence of acetic acid, extracted efficiently, independent sulfur of physical and chemical characteristics of the soils. The critical levels of sulfur in the soil were increasing in loamy soils, of low values of P-rem and with larger contents of organic matter.

The goal of this work was to evaluate the sulfur supply in soils of different textural classes using the mineral plaster originating of the region of Araripe-PE as sulfur source the sugar cane. They were installed 5 field rehearsals in different classes texturais soils to evaluate the effects of the mineral gypsum as sulfur source in the sugar cane plants nutrition. It searched the relations of the sulfur in plant, evaluating itself your availability. The rehearsals were led in the Zone of the Woods of Pernambuco. The experimental delineation employee was the one of blocks at random. The treatments in each rehearsal they constituted of the combination of 5 sulfur doses, with 3 repetitions (5 x 3). They evaluated the treatments at 16 months after the application of the sulfur doses calculated by the exchangeable aluminum neutralization and or calcium exchangeable content method, for the 0,4-0,6m soil depth layer. In the loamier soils and of smaller values of P-rem the sulfur doses promoted sugar cane larger production. The sulfur doses were enough for the sulfur supply for the sugar cane.