Raniere Barbosa de Lira

Melon yield in a hydroponic system with wastewater from desalination plant added in the nutrient solution

To use of waster water from desalting in the hydroponic cultivation, an experiment was carried out at the Department of Environmental Science of the Universidade Federal Rural do Semi-Arido-UFERSA, in the municipal district of Mossoro-RN, in pots with substrates of coconut fiber under greenhouse conditions. The experimental design was in randomized blocks, with three repetitions. Treatments were composed of five levels of salinity of the nutrient solution obtained with, and without, dilution of the waster water from desalting (2.1, 3.6, 4.9, 6.0 and 7.0 dS m-1). The variables plant height, stem diameter, leaf area, mean weight of fruit and total and marketable yield were detemined. In general, the variables decreased linearly with the increase of the salinity of the nutrient solution, showing that the salinity with waster water from desalting reduces the absorption of water by the plants due to the osmotic effect.

AVALIAÇÃO NUTRICIONAL DA PALMA FORRAGEIRA FERTIRRIGADA COM EFLUENTE DE ESGOTO DOMÉSTICO

The northeastern semiarid region faces some of the droughts of the last centuries, resulting in serious reductions of agriculture yields. The water scarcity for agricultural requires rational use practices and reuse of water, such as use of domestic effluent sewage. Alternatively, the use of treated domestic sewage effluent utilizing for irrigation of forage species, such as the forage cactus, can be highlighted. In order to evaluate the effects of fertirrigation with treated sewage effluent on mineral nutrient composition of forage cactus (Opuntia Tuna L. Mill, Mexican elephant ear), an experiment was carried out utilizing a split plot 3 x (4 + 1) with a randomized complete block design randomized block and four replications, being three planting density (66,667.00, 52,282.00 and 33,333.00 plants ha) and two water sources associated with irrigation frequency of plates fixed on 3.5 mm per irrigation (Frequencies of 2.3 days with water tap and 7, 14 and 21 days with Sewage Effluent) and cactus cultivated in Rainfed agriculture rainfed (control). The analyze of the nutritional contents of cladodes indicated that there was a significant effect of the intervals from irrigation events only for Ca and Mg concentrations. The highest levels of Ca and Mg were found with the irrigation frequency of 2.3 using tap water. The macronutrients concentration in greater quantity by the forage cactus were N e, K followed by, Ca, Mg and P. The nutritional balance indicated excess of K and P and deficiency of N, Ca and Mg, in this order.

IDENTIFICAÇÃO E PONTENCIALIZAÇÃO DOS RECURSOS HÍDRICOS NO ASSENTAMENTO PAULO FREIRE – MOSSORÓ-RN - BRASIL

Com o objetivo de identificar e potencializar os recursos hidricos do projeto de Assentamento Paulo Freire em Mossoro-RN foi realizado uma pesquisa-acao na comunidade no periodo de janeiro de 2006 a abril de 2007. Na fase exploratoria da pesquisa identificou-se, com os dialogos entre as familias, que a escassez dos recursos hidricos era o principal problema que dificultava o desenvolvimento das atividades agropecuarias. Foram realizadas oficinas para discutir e deliberar estrategias e responsabilidades na resolucao do problema caracterizado e, com a sensibilizacao e as atitudes dos assentados, conseguiu-se potencializar os recursos hidricos do assentamento, efetivando-se a recuperacao da barragem de dois acudes do assentamento. Com isso, se proporcionou o armazenamento de agua para atender as necessidades da comunidade no periodo de estiagem, evidenciando-se nos depoimentos dos agricultores e agricultoras as melhorias trazidas, alem da satisfacao e o despertar de acoes coletivas para preservacao e utilizacao sustentavel dos recursos hidricos.