Cultivo hidropônico de cultivares de alface em soluções nutritivas organominerais otimizadas com a ferramenta SOLVER

Abstract

R E S U M OObjetivou-se, com este trabalho, avaliar o cultivo de cultivares de alface em sistema hidropônico tipo floating com soluções nutritivas otimizadas pela ferramenta SOLVER, do Microsoft Office Excel. O experimento foi conduzido no Centro de Ciências Agrárias e Ambientais da Universidade Estadual da Paraíba adotando-se o delineamento experimental inteiramente casualizado disposto em esquema fatorial 4 x 3, com três repetições. Os fatores foram 4 soluções nutritivas (S1 = 100% de solução mineral; S2 = 90% de solução mineral + 10% de solução orgânica; S3 = 84% de solução mineral + 16% de solução orgânica e S4 = 78% de solução mineral + 22% de solução orgânica) e 3 cultivares de alface (C1 -Crespa; C2 -Manteiga e C3 -Rubi). Avaliaram-se a altura da planta, o diâmetro caulinar, o número de folhas, o comprimento da raiz, a massa da matéria fresca e a massa da matéria seca da alface. As soluções organominerais promoveram uma resistência maior à variação do pH e substituíram parcialmente a solução mineral. As melhores médias biométricas e de produção ocorreram para as cultivares Crespa e Manteiga e para as soluções mineral, mineral + 10% de solução orgânica e mineral + 22% de solução orgânica. Hydroponic cultivation of lettuce varieties under optimized organominerals nutrient solution with the SOLVER A B S T R A C TThe study aimed to evaluate the cultivation of lettuce varieties in floating type hydroponic system with nutrient solutions optimized by the SOLVER tool of the Microsoft Office Excel. The experiment was conducted at the Center of Environmental and Agricultural Sciences Center of the Paraíba State University, adopting an entirely randomized experimental design arranged in factorial scheme 4 x 3, with three repetitions. The factors were 4 nutritient solutions (S1 = 100% mineral solution; S2 = 90% mineral solution + 10% organic solution; S3 = 84% mineral solution + 16% organic solution and S4 = 78% mineral solution + 22% organic solution) and 3 lettuce varieties (C1 -Crespa; C2 -Monteiga and C3 -Ruby). The plant height, stem diameter, number of leaves, the length of the root, fresh matter weight and the dry matter weight of the lettuce were evaluated. The organominerals solutions promoted a greater resistance to variation of the pH and replaced partially the mineral solution. The best biometric and production means were observed for the Crespa and Monteiga varieties and for the mineral solution, mineral solution + 10% of organic solution and mineral solution + 22% of organic solution. Palavras-chave:Lactuca sativa L. fertilizante otimização

Growth of hydroponic lettuce with optimized mineral and organomineral nutrient solutions

“…Except for root length, the lower means of growth variables obtained with the use of modified solutions can be associated with the adsorption of nutrients by organic compounds, reducing the supply of the respective ions to the plants, at a level not equivalent to that of mineral solutions, which corroborates with Monteiro Filho et al (2014). Additionally, the possible presence of microorganisms in the modified solutions, from the biofertilizer used, can also influence lettuce growth (Jemba & Alexander, 1999).…”

“…Except for UO, the modified solutions (organomineral) promoted CD results similar to those found by Blat et al (2011) According to Figure 2A, the solutions BO, FM, FO and UO exhibited the highest values of root length (RL), statistically differing from the other nutrient solutions. The values found for RL with the use of these solutions are superior to 16.5 cm, reported by Monteiro Filho et al (2014) for lettuce cultivation using organomineral solutions in floating hydroponic system. Still according to Figure 2A, it is supposed that non-mineral substances, such as humic acid, from modified solutions, contributed to the higher root length in lettuce plants.…”

“…Chemical composition of the biofertilizers according to the methodology proposed by Fernandes et al (2011). The crisp lettuce seedlings were produced in phenolic foam according to the methodology described by Monteiro Filho et al (2014). The plants were evaluated at 25 days after transplanting for the following growth variables: stem diameter (SD) and crown diameter (shoots, CD), obtained through the direct measurement using a digital caliper; root length (RL), using a graduated ruler; leaf area (LA), through the leaf disc method (Benincasa, 2003); number of leaves (NL), through the count of the number of commercial leaves from the basal leaves to the last open leaf.…”

“…However, all refer to the use of mineral nutrient solutions, particularly the solution of Furlani (1995). Although scarce, in the last years a few studies on the use of biofertilizer in the production of hydroponic lettuce have been conducted, such as Costa et al (2006), Dias et al (2009) andMonteiro Filho et al (2014).…”

Mineral Composition of Lettuce Grown in Hydroponic System With Wastewater

“…They were sent for physical-chemical analysis in the Laboratory of Irrigation and Salinity (LIS/DEAg/UFCG), the physical-chemical characterization of the waters used in this work is shown in Table 2. Optimized nutrient solutions S 3 , S 5 and S 7 were prepared according to methodology proposed by Monteiro Filho et al (2014), in order to present chemical composition similar to the nutritional mineral solution of Furlani (1995). The amount of ingredients necessary for the preparation of such solutions is described in The management of the nutritive solutions were performed daily through the replenishment of the water consumed, along with the monitoring of the electrical conductivity (EC) and pH keeping it close to neutrality, with the use of a solution of NaOH ou HCL (1 mol L -1…”