Conductivity Of Nutrient Solution Research Articles

Growth characteristics of sowthistle (Ixeris dentata Nakai) under different levels of light intensity, electrical conductivity of nutrient solution, and planting density in a plant factory

The objective of this study was to investigate the growth characteristics of sowthistle (Ixeris dentata Nakai) under different levels of light intensity (photosynthetic photon flux, PPF), electrical conductivity (EC) of nutrient solution, and planting density for efficient production in a closed-type plant factory system. Growth and yield of the plants were analyzed at EC 1.5 and 2.0 dS·m−1 with PPF 100 and 200 μmol·m−2·s−1. Further, growth and yield were measured under four different planting densities: a 15-cm between-row distance with within-row distances of 10, 15, 20, and 25 cm. Shoot dry weight and leaf photosynthetic rate all increased with increasing EC and light intensity. Shoot fresh and dry weights, chlorophyll content, and leaf photosynthetic rate were maximal at EC 2.0 dS·m−1 with PPF 200 μmol·m−2·s−1. For all planting densities, number of leaves and leaf width were not significantly different. Shoot fresh and dry weights per plant were not significantly different, however, shoot fresh and dry weights per area decreased with increasing plating densities. A linear relationship was observed between the number of leaves and days after transplantation. Based on the results, we suggest a nutrient solution of EC 2.0 dS·m−1, PPF 200 μmol·m−2 · s−1, and planting density of 15×10 cm for maximal growth and yield of sowthistle in a closed-type plant factory.

Retenção de soluções de sulfatos por hidrogel de policrilamida

The hydrogel use in the brazilian agriculture, mainly in the forestation, fruits field, and growth media, is being consolidated by its capacity of holding and release water (nutrient solution) to plants. This work aimed to study the holding capacity of nutrient solutions by hydrogel when submitted into differents solutions from sulphates. This study was conducted out the Irrigation Technical Center of Universidade Estadual de Maringá, Maringá, Paraná State. It was conducted in a 5 x 5 factorial way (with 26 treatments and 04 replications) and the randomized design. It was used as treatments 05 fertilizers sulphates base (ferrous sulphate, ammonium sulphate, zinc sulphate, copper sulphate, and magnesium sulphate) and 05 doses (0.4; 0.8; 1.2; 1.6, and 2.0 g to each 500 g of distilled water). The distilled water treatment and hydrogel were used as control treatment. The hydrogel was hydrated for 24 hours for a later measure of holding capacity of nutrient solution. We noticed that besides the electric conductivity of nutrient solution the different fertilizer interfered with the holding capacity of nutrient solution.