Because of the food and industrial importance of tomato, it holds great significance, and is one of the most produced species using the hydroponic cultivation systems. The objective of this study was to evaluate the effects of different concentrations of nutrient solution on the production and quality of cherry tomatoes (Lycopersicon esculentum 'Samambaia') grown in a hydroponic system in protected conditions. The experiment was conducted in pots filled with coconut fiber substrate using a randomized complete block design with four replications and six plants per plot. Five concentrations of nutrients were evaluated (50, 75, 100, 125, and 150% of the standard nutrient solution); the solutions produced the following electrical conductivities: 1.8, 2.0, 2.6, 3.4, and 3.9 dS m -1 , respectively. At 90 days after transplanting, the tomato fruits were harvested, at which time the production variables and post-harvest quality of mature fruits were determined. The best production and post-harvest quality indexes of cherry tomatoes ('Samambaia') were found when using 111% of the standard nutrient solution, corresponding to the concentrations of 9. 44, 2.44, 2.22, 6.44, 4.11, 2.44, and 2.78 mmolc L -1 , of NO3 -, NH4 + , P, K, Ca, Mg, and S, respectively; and 66.6, 55.5, 14.4, 1.89, 0.56, and 0.44 mmolc L -1 , of Fe, B, Mn, Zn, Cu, and Mo, respectively. Nutrient solutions with electrical conductivity above 2.89 dS m -1 severely reduced the fruit yield of cherry tomatoes.

Resumo: Na fase de produção de mudas de tomate, a utilização do extrato de alga Ascophyllum nodosum pode se tornar uma alternativa orgânica viável na agricultura, como uma alternativa de biofertilizante, estimulando através de seus compostos o crescimento vegetativo das culturas que recebem efeito de sua aplicação. Dessa maneira, objetivou-se com esta verificar o crescimento e desenvolvimento de mudas de tomate IPA 6 sob o efeito do extrato de Ascophyllum nodosum. O experimento foi conduzido em casa de vegetação na Horta didática do Centro de Ciências Agrárias da Universidade Federal Rural do SemiÁrido, campus Mossoró, Rio Grande do Norte, no período de junho a julho de 2015. O delineamento experimental utilizado foi o inteiramente casualizado com 4 tratamentos (0; 0,3; 0,6 e 0,9 mL L -1 ) de doses do fertilizante foliar a base de algas marinhas Ascophyllum nodosum, com quatro repetições e cada parcela foi representada por 12 plantas da variedade de tomate IPA 6. Foram avaliadas as seguintes características: número de folhas (NF), altura de plântula (AP), comprimento da raiz (CR), diâmetro de caule (DC), matéria seca total (MS) e relação AP/DC. Exceto para a relação AP/DC, todas as características avaliadas obtiveram os maiores resultados na dose de 0,9 mL L -1 aplicada a cada 7 dias. Assim podemos concluir que essa dose proporciona uma melhor qualidade da muda do tomateiro e pode ser recomendada para utilização. Palavras-chave:Solanum lycopersicum L.; Doses; Algas; Solanaceae. Abstract:In the production phase of tomato seedlings, the use of Ascophyllum nodosum seaweed extract can become an organic viable alternative in agriculture, as an alternative biofertilizer, stimulating through its compounds the vegetative growth of the cultures that receive effect of its application. Thus, the present research aimed to verify the growth and development of IPA 6 tomato seedlings under the effect of Ascophyllum nodosum extract. The experiment was carried out in a greenhouse at the Agricultural Science Center of the Federal Rural Semi-Arid University, Mossoró campus, Rio Grande do Norte, from June to July 2015. The experimental design was a completely randomized design with four treatments (0, 0.3, 0.6 and 0.9 mL L -1 ) of doses of foliar fertilizer based on seaweed Ascophyllum nodosum, with four replications and each plot represented by 12 plants of the IPA 6 tomato variety. The research evaluated the following characteristics: leaf number, seedling height, root length, stem diameter, total dry matter and seedling height/stem diameter ratio. Except for seedling height/stem diameter ratio, all evaluated characteristics obtained the highest results at the dose of 0.9 mL L -1 applied every 7 days. Thus, we can conclude that this dose provides a better quality of tomato seedlings, being the dose recommended for utilization.

The scarcity of good water quality in semiarid region, combined with the high cost of pumping, has been the main limiting factor for increasing the irrigated area. The use of saline water for irrigation is a very common in semiarid zones, which can result in the soil salinization if irrigation management is not appropriated. To evaluate the biomass production, biochemical components and water consumption of Tanzania grass (Panicum maximum) irrigated with water salinity (1.5, 3.0, 4.5 and 6.0 dS m-1) an experiment in greenhouse was carried out in the Universidade Federal Rural do Semi-Árido, Mossoró, Rio Grande do Norte State, Brazil. The variables dry matter, crude protein, ashes, cellular damage on leaves and consume water in the first and second cut of the grass were analyzed under completely randomized design with five treatments and six replications. Salinity water up to 6.0 dS m-1 can be used for irrigation of Tanzania grass plants, with small yield losses. Increased salinity reduces water consumption and increases the water use efficiency of Tanzania grass. Tanzania grass plants have increased protein content when subjected to saline stress, which is a mechanism of action to osmotic adjustment and allows the reduction of plant leaf damage in the second cycle.

The volume of biodegradable solid waste and its inadequate disposal have led to serious environmental problems, requiring efficient measures that prioritize the recycling of these wastes, promoting sustainability. The objective of this research was to monitor the behavior of physical parameters during the organic waste composting process. For this, 5 piles of organic waste were built through the composting technique developed according to the windrow method. The piles were composed of 70% of plant material, and 30% varied between manure and food remains. The piles were composed of 70% of plant material, and 30% varied between manure and food remains. The proportions were: I pile, 1:1 (15% manure and 15% rest of food); Pile II, 2:1 (20% manure and 10% rest of food); Cell III, 1:2 (10% manure and 20% rest of food); (30% manure and 0% rest of food) and the V pile in the ratio of 0:3 (0% manure and 30% rest of food). The evaluated parameters were temperature, moisture, pH, TOC, TN and C/N ratio. During the process of compost maturation, the parameters evaluated were kept within the established standards for the composting process.

Soil water logging reduces the availability of oxygen to the roots of the plants, which makes necessary an efficient drainage system for correction. Thus, the objective of this study was to evaluate the tolerance of sugarcane in flooded crop with different velocities of lowering the groundwater in three stages of ratoon sugarcane development. The experiment was carried out in a randomized complete block design (3 x 5 + 1), with three developmental stages (44, 210 and 305 days after planting) and five groundwater falling velocities (30 cm in 3, 6, 9, 12 and 15 days) and the control (irrigation without flooding the soil). There was a significant effect for groundwater retraction velocities and evaluation periods for leaf area (LA) and leaf area index. The treatments P1V4 and P2V3 presented the highest LAs (0.91 m²). The first sugarcane ratoon was tolerant to soil waterlogging at different stages of development and to different groundwater falling velocities, with no major losses in plant development and productivity, however, for total recoverable sugar cane ratoon was more sensitive when the flood occurred in the regrowth stage.