O uso do território pela fruticultura irrigada no Rio Grande do Norte: uma análise a partir do circuito espacial produtivo do melão (cucumis melo l.)

In recent decades the production of irrigated fruits destined to supply the foreign market reveals itself as an expression of the thriving agricultural modernization, consisting an important and dynamic segment of Brazilian agribusiness, especially in the Northeast. The Rio Grande do Norte contributes to this scenario through the production of several tropical fruit, especially melon production in the municipalities of Baraúna/RN and Mossoró/ RN. Accordingly, the overall goal of the study is to understand the agricultural use of the territory of Rio Grande do Norte by irrigated orcharding from the circuit productive space configuration of melon. The outlook presented in the work on the irrigated agriculture developed in Rio Grande do Norte reveals that it falls within an agricultural division of labor, through productive specialization of places that have natural and technical conditions favorable to the exploitation and reproduction of capitals. The land use caused by circuit productive space melon enables flows of tangible and intangible consolidate a extraverted network of production and consumption in order to meet the requirements of foreign markets

Caracterização do lodo de lagoa anaeróbia tratando resíduos esgotados de tanques sépticos e fossas com vistas ao aproveitamento

The sludge generated in stabilization ponds can be designed for various purposes, among them we mention agricultural use, recovery of degraded areas and civil construction. The choice of these alternatives should be made based on qualitative and quantitative characteristics of the sludge. In this context, this study characterized the digested sludge from an anaerobic lagoon in Cidade do Natal/RN, which deals exclusively with residues of depleted septic tanks and pits. The sludge showed levels of macro and micronutrients that confirm its potential for agriculture, with 139.49 g.kg -1 organic matter, 15.40 g.kg-1 nitrogen and metal concentrations below those required by Resolution No. 375/06 of CONAMA, besides the absence of fecal coliform and less than 0.15 viable helminthes eggs/g, on average. The particle size distribution showed that most of the particles have a diameter similar to the sand, allowing the replacement of this input, for example. Analysis of the leachate and of the sludge solubilized classified as non-inert and non-hazardous according to NBR 10.004/04. The volume produced in three years of operation by the pond was 1903.50m³, equivalent to approximately 400 kg of dry sludge. Overall, the concentrations of the parameters were similar to literature, although none of them addresses sludge anaerobic pond treating sewer from septic tanks and pits.The sludgepresents technical feasibility to various types of use, however the cost of dewatering and especially with transport can derail it. It needs to be made a more thorough study of the costs to prove its economic viability

Uso da glicerina oriunda da síntese do biodiesel em sistemas microemulsionados visando aplicação de herbicidas

The program PROBIODIESEL from the Ministry of Science and Technology has substantially increased glycerine, obtained as a sub-product of biodiesel production process, making it necessary to seek alternatives for the use of this co-product. On the other hand, herbicides although play a role of fundamental importance in the agricultural production system in force, have been under growing concern among the various segments of society because of their potential environmental risk. In this work, we used glycerin in microemulsion systems for application of herbicides, to improve efficiency and lower environmental pollution caused by the loss of those products to the environment. To obtain the systems of microemulsinados were used Unitol L90 NP and Renex 40 as surfactants, butanol as co-surfactant, coconut oil as oil phase and aqueous phase as we used solutions of glycerin + water. Through the determination of phase diagrams, the microemulsion region was found in the system E (L90 Unitol, coconut oil and glycerin + water 1:1). Three points were chosen to the aqueous phase rich in characterization and application in the solubilization of glyphosate and atrazine. Three experiments were performed in Horta, Department of Plant Sciences, Plant Science Sector, UFERSA, Mossoró-RN. The first experiment was conducted in randomized complete blocks with 20 treatments and four replications. The treatments consisted of five doses of the herbicide glyphosate (0.0, 0.45, 0.9, 1.35 and 1.8 L ha-1) diluted with four sauces: C1, C2, C3 (microemulsions) and C4 (water). The phytotoxicity of Brachiaria brizantha was measured at 7, 14, 28 and 60 DAA (days after application). At 60 DAA, we evaluated the biomass of plants. The second experiment was developed in randomized complete blocks with 20 treatments and four repetitions. The treatments consisted of five doses of the herbicide atrazine (0.0, 0.4, 0.8, 1.6 and 2.4 L ha-1) diluted with four sauces: C1, C2, C3 (microemulsions) and C4 (water). The phytotoxicity on Zea mays and Talinum paniculatum was evaluated at 2, 7, 20 DAA. The experiment III was developed in randomized complete blocks with 16 treatments and three repetitions. The treatments consisted of 16 combinations among the constituents of the microemulsion: Unitol L90 surfactant (0.0, 1.66, 5.0, 15 %) and glycerin (0.0, 4.44, 13.33 and 40.0 %). The phytotoxicity on Zea mays was evaluated at 1, 7 and 14 DAA. At 14 DAA, we evaluated the biomass of plants. The control plants using the microemulsions was lower than in the water due to the poisoning caused by the initial microemulsions in the leaves of the plants, a fact that hinders the absorption and translocation of the herbicide. There was no toxicity in Zea mays plants caused by the herbicide, however, were highly intoxicated by microemulsions. T. paniculatum was better controlled in spraying with the microemulsions, regardless of the dose of the herbicide. The glycerine did not cause plant damage. Higher poisoning the plants are caused by tensoactive Unitol L90 and higher rates occur with the use of higher concentrations of surfactant and glycerin, or microemulsion. The microemulsions used hampered the action of glyphosate in controlling B. brizantha and caused severe poisoning in corn, and these poisonings attributed mainly to the action of surfactant

Avaliação do desenvolvimento da região de Cruzeta (RN), através do uso intensivo de água para irrigação

This work aims for the evaluation of Cruzeta Irrigated Perimeter, RN, which consists in the efficient use of water for agricultural production. The goal is looking for the available quantity of water for supplying required demands for adequate and economically viable cultures for the region. It is supposed that regional community water is supplied by pipelines from sources located outside of the region. From this study it is recommended the implantation of adequate installments for culture management in accordance with the availability of water resources and others conditionings. It must be considered the intensity of rainy and drought seasons in order to adjust the cultivated area and equipments to be operated, and also, the use of operating models and simulations in order to establish alert levels and eventually, reduction of irrigated area. Based on obtained data it is proposed the cultivation of different types of non-permanent cultures so that temporary cultures would be extensively produced in periods of abundant reservoir storage water permitting the transformation of storage water in storage culture products and few or no production in severe drought periods. This is the basic premise for sustainable agricultural development for Brazilian semiarid region

Avaliação do potencial tóxico de águas oriundas de irrigação agrícola no Baixo-Açu/RN: um problema socioambiental

For many decades the problematic raised about the indiscriminate use of pesticides in modern agriculture has incited the interest of many researchers to discover the effects caused by such products in the environment and consequently in the life of the ones which use that products (farmers) and those people who live in places next to the agricultural areas. Facing these facts, this research had the intention of comprehend the environmental perception of habitants of the Distrito Irrigado do Baixo-Açu (DIBA), located in the semiarid of Rio Grande do Norte, by using agro toxics and its possible environmental effects, as well as evaluate the levels of toxicity of waters from agricultural runoff in this region by using eco-toxicological exams with Ceriodaphnia silvestii. Were done 86 interviews with dwellers and farmers from DIBA. With the results reached in the evaluation of the interviews it was possible to identify that one of major problems is the inappropriate discard of empty packs of the pesticides used at that place. The samples collected for eco-toxicological evaluation showed a variation in its toxicity, once that the point of collect which receives waters from different cultures presented in four out of five samples toxicity for the tested species. Therefore, it concludes that the indiscriminate use of pesticides agricultural practice presented a potential to pollute to the irrigation waters, and the absence of elucidation by the farmers about the manipulation of these products contribute to the risk of environmental contamination and the possible decrease of the quality of life of the dwellers of the region

Uso da glicerina oriunda da síntese do biodiesel em sistemas microemulsionados visando aplicação de herbicidas

The program PROBIODIESEL from the Ministry of Science and Technology has substantially increased glycerine, obtained as a sub-product of biodiesel production process, making it necessary to seek alternatives for the use of this co-product. On the other hand, herbicides although play a role of fundamental importance in the agricultural production system in force, have been under growing concern among the various segments of society because of their potential environmental risk. In this work, we used glycerin in microemulsion systems for application of herbicides, to improve efficiency and lower environmental pollution caused by the loss of those products to the environment. To obtain the systems of microemulsinados were used Unitol L90 NP and Renex 40 as surfactants, butanol as co-surfactant, coconut oil as oil phase and aqueous phase as we used solutions of glycerin + water. Through the determination of phase diagrams, the microemulsion region was found in the system E (L90 Unitol, coconut oil and glycerin + water 1:1). Three points were chosen to the aqueous phase rich in characterization and application in the solubilization of glyphosate and atrazine. Three experiments were performed in Horta, Department of Plant Sciences, Plant Science Sector, UFERSA, Mossoró-RN. The first experiment was conducted in randomized complete blocks with 20 treatments and four replications. The treatments consisted of five doses of the herbicide glyphosate (0.0, 0.45, 0.9, 1.35 and 1.8 L ha-1) diluted with four sauces: C1, C2, C3 (microemulsions) and C4 (water). The phytotoxicity of Brachiaria brizantha was measured at 7, 14, 28 and 60 DAA (days after application). At 60 DAA, we evaluated the biomass of plants. The second experiment was developed in randomized complete blocks with 20 treatments and four repetitions. The treatments consisted of five doses of the herbicide atrazine (0.0, 0.4, 0.8, 1.6 and 2.4 L ha-1) diluted with four sauces: C1, C2, C3 (microemulsions) and C4 (water). The phytotoxicity on Zea mays and Talinum paniculatum was evaluated at 2, 7, 20 DAA. The experiment III was developed in randomized complete blocks with 16 treatments and three repetitions. The treatments consisted of 16 combinations among the constituents of the microemulsion: Unitol L90 surfactant (0.0, 1.66, 5.0, 15 %) and glycerin (0.0, 4.44, 13.33 and 40.0 %). The phytotoxicity on Zea mays was evaluated at 1, 7 and 14 DAA. At 14 DAA, we evaluated the biomass of plants. The control plants using the microemulsions was lower than in the water due to the poisoning caused by the initial microemulsions in the leaves of the plants, a fact that hinders the absorption and translocation of the herbicide. There was no toxicity in Zea mays plants caused by the herbicide, however, were highly intoxicated by microemulsions. T. paniculatum was better controlled in spraying with the microemulsions, regardless of the dose of the herbicide. The glycerine did not cause plant damage. Higher poisoning the plants are caused by tensoactive Unitol L90 and higher rates occur with the use of higher concentrations of surfactant and glycerin, or microemulsion. The microemulsions used hampered the action of glyphosate in controlling B. brizantha and caused severe poisoning in corn, and these poisonings attributed mainly to the action of surfactant