Saline stress is a frequent phenomenon in the arid and semi-arid regions of the globe, affecting the agricultural production of these regions, and it is necessary to use strategies that minimize the impacts of saline stress under agriculture. This requires the incorporation of species, variety and genotypes tolerant to increase agricultural production in those regions. This study aimed to evaluate germination and initial growth of cowpea genotypes under salt stress. The experimental design was completely randomized in 19 x 3 factorial scheme, composed of nineteen cowpea cultivars and three osmotic potentials, with four replicates of 50 seeds each. The germination test lasted for eight days, when the seeds were evaluated for germination percentage, germination speed index, length of shoot and root, accumulation of dry mass of shoot and root. The increase in salinity affected germination and initial growth of the cowpea genotypes. The genotypes 6 -MNCO2-689F-2-8, 10 -MNCO2-675F-4-10, 12 -MNCO3-737F-5-9, 16 -MNCO2-677F-2, 18 -BRS-Pajeú and 19 -Paulistinha exhibited higher tolerance to salt stress in the stage of germination and initial growth. The genotypes 11 -MNCO2-675F-9-5, 13 -BRS-Tumucumaque, 15 -MNCO3-736F-7 and 17 -BR17-Gurgueia were more susceptible to the effects of salt stress in the stage of germination and initial growth.

O zoneamento agroclimático é uma ferramenta importante na determinação do potencial agrícola de uma região, podendo auxiliar no planejamento das atividades agrícolas. Assim, objetivou-se determinar o potencial agroclimático para o cultivo da mangueira (Mangifera indica L.) visando dar informações para a implantação da cultura no município de Barbalha-CE. Para isso, utilizou-se uma série histórica de 44 anos de dados meteorológicos, referente ao período de 1973 a 2016 de precipitação pluviométrica e temperatura média do ar para o cálculo do balanço hídrico climatológico e do índice de umidade. Na determinação do potencial agroclimático, utilizaram-se as faixas do índice de umidade anual (Iu) e da temperatura do mês mais quente (Tq). Os parâmetros climáticos médios foram: precipitação pluviométrica 1053,9 mm ano-1 , índice de umidade-10,8% e temperatura do ar referente ao mês mais quente 27,4 ºC. O município de Barbalha-CE possui potencial agroclimático pleno para o cultivo da mangueira desde que complementada com irrigação. O município de Barbalha-CE possui potencial agroclimático pleno para o cultivo da mangueira com a necessidade de irrigação complementar principalmente no segundo semestre do ano. Os resultados alcançados com este estudo proporcionam subsídios para a implantação da cultura pelos produtores do município. Palavras-chave: índices climáticos, aptidão hídrica e térmica, Mangifera indica L.

Currently there is a great need for reuse of water in agricultural activity, aiming at reducing environmental impacts and production costs. The objective of this study was to evaluate the fruit production of hybrid Satrapo bell pepper, under fertilization with yellow water and cassava wastewater. The experiment was conducted in a greenhouse located at Campina Grande city, PB. The experimental design was completely randomized, with eight treatments and five replications, totaling 40 experimental plots. The treatments were characterized by fertilization with cattle manure (EB); NPK; human urine (HU); cassava wastewater (M); cassava wastewater and human urine (UH+M); the double volume of human urine (2xUH); the double volume of cassava wastewater (2xM); and the double volume of human urine and cassava wastewater (2xUH+M). At 60 day after transplanting (DAT) were evaluated the diameter, thickness of mesocarp, fresh and dry phytomass and number of lobes of yellow bell pepper fruits.According to the results, there were significant differences in the variables analyzed due to the treatments applied. The treatment corresponding to 2xM provided the highest results for length, diameter, thickness of the mesocarp, fresh and dry phytomass of the bell pepper fruits. On the contrary, 2xUH was the treatment that provided the lowest values for these variables and provided the highest number of lobes.

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The objective of the present study was to evaluate the effect of nitrogen doses applied via fertigation and associated with different types of crop establishment fertilization on growth and biomass of radish. The experiment was conducted in a greenhouse of the Academic Unit of Agricultural Engineering, Federal University of Campina Grande, from April to May 2014. Treatments consisted of five doses of nitrogen fertilizer applied by fertigation (0, 0.7, 1.4, 2.1 and 2.8g per pot) and three types of crop establishment fertilization (humus 2:2; NPK and control), arranged in a 5 x 3 factor design with four repetitions. The 15 treatments were arranged in 60 plots. The nitrogen source used in the study was urea, divided in three applications: the first application was carried out eight days after transplanting, the second, on day 15, and the third, on day 22. The crop establishment fertilization significantly influenced the growth variables and plant mass of the radish on day 35 after transplanting. The highest values of the variables (number of leaves, plant height, bulb diameter, leaf area, fresh mass of the aerial part, dry mass of the aerial part and root/aerial part were observed in the treatment with humus on day 35 after transplanting. The dose of 2.8g nitrogen per pot corresponding to 6.22g of urea per plant provided the highest yield for the variable number of leafs, leaf area and root length on day 35 after transplanting.

The objectives were to analyze the water and nitrogen use efficiency by forage palm in different irrigation depths with saline water and nitrogen fertilization levels in the Brazilian semi-arid region. The experiment was conducted under field condition during one year of cultivation (360 days). The experimental design was a complete randomized block and 5 x 5 factorial scheme with five irrigation depths (125, 100, 75, and 25% of ET0) and five levels of nitrogen fertilization (0, 150, 300, 450 and 600 kg ha-1 of N) and three replicates. Irrigation and acceptable nitrogen fertilization resulted in a good water and fertilization management. Water and nitrogen use efficiency of forage palm were higher, when water depths and the nitrogen levels supplied to the soil were increased. The 125% ET0 depth showed a higher efficiency of water and nitrogen use in the forage palm during 360 days of study. In conditions of low nitrogen supply, the efficiency of nitrogen use is directly and indirectly associated with the fresh mass yield; while under high supply, the efficiency of the use of nitrogen is more effective. The use of irrigation and nitrogen fertilization in the semi-arid region is recommended to obtain higher productivity of water and nitrogen from the forage palm.

RESUMOO conhecimento da umidade do solo é relevante para a decisão de quando e quanto irrigar, para isto, são vários os métodos para determinação das condições hídricas em que o solo se encontra. Objetivou-se com este estudo comparar o teor de umidade obtido por diferentes métodos em Neossolo Flúvico do semiárido brasileiro. O experimento foi realizado em condições de campo no munícipio de Santa Luzia -PB. Utilizou-se os métodos padrão da estufa, forno elétrico e sonda FDR, nas profundidades de 0,0-0,5 m com sete repetições. Os métodos foram comparados através de indicativos estatísticos e dos valores de umidade do solo obtidos pelo método padrão, com aqueles determinados pelos métodos testados. O teor de umidade obtido pelo forno elétrico foi muito próximo do obtido no método padrão, além de melhor ajustamento entre os dados e maior coeficiente de determinação, diferentemente, os valores obtidos pela sonda FDR proporcionou uma maior variação quando comparado ao método padrão. O forno elétrico proporcionou desempenho ótimo em relação ao método padrão, enquanto a sonda FDR foi classificada como mediano. O teor de umidade do solo determinada pelo forno elétrico é uma alternativa viável para o manejo da irrigação, por ser de baixo custo e menor tempo de obtenção dos resultados 0,58 h quando comparado ao padrão da estufa de 24 a 48 h. Palavras-chave: conteúdo de água do solo; métodos alternativos; indicativos estatísticos. MOISTURE CONTENT BY DIFFERENT METHODS IN NEOSSOLO OF BRAZILIAN SEMIARID ABSTRACTThe knowledge of soil moisture is relevant to the decision of when and how much to irrigate, for this, there are several methods for determining the water conditions in which the soil is found. The objective of this study was to compare the moisture content obtained by different methods in the Neossolo Flúvico of the Brazilian semiarid. The experiment was carried out under field conditions in the municipality of Santa Luzia -PB. Was used the methods standard

The grey water footprint (GWF) is defined as the volume of freshwater that is required to dilute pollutants to make them harmless. The objective of this study was to evaluate the grey water footprint and its sustainability for onion cultivation in the Brazilian semiarid regions. The work was developed in the Brazilian semi-arid region in an area corresponding to 10 thousand hectares of onion cultivation under surface irrigation. A survey of the main pollutants was carried out, in addition to the environmental conditions of soil and climate, soon after using mathematical models to estimate the grey water footprint and sustainability. The agrochemicals Ronstar 250 BR, Dicarzol 500 PS and Sportak 450 CE are classified as having the highest grey water footprint for onion cultivation in the Brazilian semi-arid region; thus requiring a higher volume of freshwater for pollutants dilution to convert them to harmless. It is recommended to replace these agrochemicals with others of smaller GWF. According to the obtained results, it can be concluded that the grey water footprint is an efficient indicator in monitoring the impact of man on the environment. The semi-arid regions of Brazil classified as sustainable for the cultivation of irrigated onions.