ABSTRACT Effluent from fish farming with saline water is a source of water, also rich in organic matter and nutrients, that can be used in irrigation of cultivated plants and even fully or partially replace mineral fertilization. The objective was to evaluate the growth, biomass production and quality of P. maximum cultivars fertigated with fish farming effluent in a greenhouse experiment, using a randomized block design with eight replicates. Treatments were arranged in a split-split-plot scheme, with three irrigation managements in the plot (irrigation with public-supply water, irrigation with public-supply water + conventional fertilization, and irrigation with fish farming effluent), three cultivars of P. maximum (Tanzania, Mombasa, and Massai) in the sub-plot, and four cutting times in the sub-sub-plot (45, 90, 135, and 180 days after sowing). Plant height, number of tillers, production of fresh biomass, neutral detergent fiber, acid detergent fiber, ether extract, crude protein, dry matter, and mineral matter contents were analyzed. The highest growth, production, and quality of P. maximum grass occurs when irrigated with public-supply water and under conventional NPK fertilization. Fertigation with fish farming effluent reduces the growth and production of P. maximum grass, but allows obtaining better quality forage. It is possible to irrigate P. maximum grass using fish farming effluent with satisfactory yields. The growth of cv. Massai was more sensitive to irrigation with fish farming effluent than those of the cultivars Tanzania and Mombasa. nutrients fertilization P experiment replicates splitsplitplot split scheme publicsupply public supply effluent, , effluent) Tanzania, (Tanzania Mombasa subplot, subplot sub plot, sub-plot subsubplot 45, 45 (45 90 135 18 sowing. sowing . sowing) height tillers fiber extract protein analyzed forage yields cv 4 (4 9 13 1 (

Resumen El experimento se realizó en 2014, en un diseño factorial completamente al azar (5x6), con tres repeticiones. Los factores fueron clases de suelo (tipic Ustipsamments, Typic Haplustults, Typic Haplustepts, Typic Ustifluvents y Typic Haplusterts) y niveles de salinidad del agua de riego (0.5, 1.0, 2.0, 3.0, 4.0 y 5.0 dS m-1). El aumento de la salinidad del agua de riego provocó un aumento en el contenido de las hojas de los macronutrientes en todos los suelos. Se observaron contenidos foliares adecuados de N, K y Mg en plantas cultivadas en todos los suelos excepto K en Typic Haplusterts y Mg en Typic Ustipsamments. Los niveles apropiados de P se observaron solo en Typic Haplustepts, y Ca solo en Typic Haplustults y típicos Ustifluvents. El aumento de la salinidad del agua de riego provocó un aumento en el contenido foliar de micronutrientes en todos los suelos, excepto el cobre en los típicos Ustifluvents, el hierro en los Typic Haplusterts y Typic Haplustults, y el manganeso en Typic Ustipsamments y Typic Haplustults.

Abstract The experiment was conducted in 2014, in a completely randomized factorial design (5x6), with three replications. The factors were soil classes (Typic Ustipsamments, Typic Haplustults, Typic Haplustepts, Typic Ustifluvents, and Typic Haplusterts) and levels of irrigation water salinity (0.5, 1.0, 2.0, 3.0, 4.0, and 5.0 dS m-1). Increasing salinity of irrigation water caused increase in leaf contents of macronutrients in all soils. Adequate leaf contents of N, K, and Mg were observed in plants grown in all soils except K in Typic Haplusterts and Mg in Typic Ustipsamments. Appropriate P levels were observed only in Typic Haplustepts, and Ca only in Typic Haplustults and Typic Ustifluvents. Increased salinity of irrigation water caused increased leaf contents of micronutrients in all soils except copper in Typic Ustifluvents, iron in Typic Haplusterts and Typic Haplustults, and manganese in Typic Ustipsamments and Typic Haplustults.

El objetivo de ésta investigación fue analizar la viabilidad económica del cultivo del melón Pele de Sapo regado con agua de baja y alta concentración salina, aplicado en forma alternada, por ciclo de desarrollo del cultivo o mixto. El trabajo constó de dos experimentos llevados a cabo entre noviembre de 2008 a noviembre de 2009, en el predio de Pedra Preta, ubicado en Mossoró, RN, Brasil. En el experimento I, el melón (Cucumis melo L., cv Sancho) se regó con agua de baja salinidad (CEa = 0,5 dS m-1) y alta salinidad (CEa = 4,3 dS m-1), aplicado diariamente en forma alternada, variando por cada fase fenológica del cultivo o sin cualquier alteración, haciendo un total de 10 tratamientos; en el experimento II algunos tratamientos del primer ensayo fueron repetidos y evaluados, sumando otro tratamiento, equivalente a una mezcla de dos tipos de agua, utilizando las variedades de melón Sancho y Medellín. El manejo con agua salina en el riego del melón fue económicamente viable, principalmente en el tratamiento en que se regó cada dos días con agua de baja salinidad y cada día con agua salina, proporcionando un ahorro de cerca del 33% de agua de baja salinidad, proporcionando una margen de lucro de 72%.

The objective of this research was to study the economical viability of the melon crop irrigated with water of the low and high salt concentration, applied alternately, by stage of development of crop or mixed. The study consisted of two experiments, conducted between November 2008 and November 2009 at the Pedra Preta Farm in Mossoró, RN, Brazil. In experiment I, the melon (Cucumis melo L., cv Sancho) was irrigated with water of low (ECw = 0.5 dS m-1) and high salinity (ECw = 4.3 dS m-1) applied daily alternately, varying by crop growth stage or without amendment, totaling 10 treatments. In the second experiment, we repeated same treatments of the first trial, plus other treatment that corresponded to a mixture of both types of water, using the cultivars Sancho and Medellin. Different forms of management of saline water irrigation of muskmelon was economically feasible, especially the treatment in which the crop was irrigated two days with water of low salinity and one day with saline water, providing a saving of about 33% water of low salinity, providing a profit margin of 72%.

Avaliaram-se os efeitos do uso de diferentes níveis de salinidade da água de irrigação (S1 = 0,55 dS/m, S2 = 1,70 dS/m, S3 = 2,85 dS/m e S1 = 4,00 dS/m) no crescimento vegetativo de bananeiras Pacovan (AAB) e Marmelo (ABB), utilizando-se um solo Argissolo Crômico, textura franco-argilo-arenosa e adotando-se um delineamento experimental em blocos completos casualizados, com parcelas subdivididas e quatro repetições. As parcelas experimentais foram compostas de uma fileira com 10 plantas, sendo cinco de cada cultivar, com as três plantas centrais de cada sub-parcela consideradas úteis. As irrigações foram feitas diariamente ou a cada dois dias de modo a proporcionar uma fração de lixiviação ao redor de 0,15%, colocando-se volumes aproximados de água para manter o solo próximo à capacidade de campo. Os resultados obtidos aos 110, 160, 220, 300 e 360 dias após o plantio mostraram que o incremento nos níveis de salinidade diminuiu significativamente a altura da planta, o número de folhas e a área foliar com o aumento do nível de salinidade da água até no máximo 240 dias do desenvolvimento, havendo uma equiparação depois do período chuvoso.

The effects of different salinity levels of irrigation water (S1 = 0.55 dS/m, S2 = 1.70 dS/m, S3 = 2.85 dS/m e S4 = 4.00 dS/m) on vegetative growth in bananas Pacovan (AAB) and Marmelo (ABB) were evaluated. The experiment was carried out on a sandy clay loam Chromic Argisol in a split-plot scheme arranged in a randomized block design with four replications. The whole plots were composed of a row with 10-plants, five plants of each cultivar (subplot), and the data were collected from the three central ones. The irrigations were applied either dayly or every each two-days period in order to maintain a lixiviation fraction of 0.15, using approximate water sheets to keep the soil at field capacity. The data obtained at 110, 160, 220, 300, and 360 days after planting indicated that the water salinity level increase caused plant height, number of leaves, and leaf area to decrease significantly up to 240 days of the growth period, with the values becoming equalled after the rainy period.

Estimou-se a área foliar da cultura do melão (Cucumis melo, L.) cv. Gold Mine, submetido a lâminas de irrigação variando de 55% a 130% da necessidade híbrida da cultura, usando água de baixa e alta salinidade. Foi coletada uma planta em cada parcela, aos 19; 26; 34; 40 e 50 dias após a semeadura, onde se determinou o número e a área foliar total e as suas dimensões, e a área foliar individual até 24 folhas por planta. Os resultados evidenciaram que existe uma correlação parcial entre a área foliar total da planta e o número de folhas de 0,945**, e a equação de regressão obtida foi AF = 108NF - 516, com r² = 0,95. A comparação conjunta das equações obtidas para cada época mostra que pelo menos uma relação entre largura (L) e área foliar (AF) diferenciaram das demais, embora a relação que assume os dados como um todo, apresente um alto valor para o coeficiente de determinação, sendo a seguinte: AF=0,826L1,89 (r²=0,97).

The leaf area of the Gold Mine melon was estimated when submitted to irrigation water levels varying from 55% to 130% of the hydric necessity of the crop, utilizing low and high salinity water. One plant per plot was collected at 19; 26; 34; 40 and 50 days after sowing, obtaining data of length, width, total leaf area, number of leaves, and individual leaf areas up to 24 leaves per plant. The results indicated that a partial correlation between the total plant leaf area (AF) and the number of leaves (NF) exists, with r² = 0.95**, and the regression equation AF = 108NF - 516, with r² = 0.95. The comparison of the models showed that at least one relation between leaf width (L) and leaf area (AF) differentiated from the others, even though the relation that assumes the whole data set (AF=0,826L1,89; r² = 0.97) has a high determination coefficient.