Macro-, mesoelement and sodium content of plant parts of energy willows irrigated with effluent water of agricultural origin

Abstract

Irrigation of recycled water can be considered as an element of integrated water management, in which the nutrients in the water are used and decomposed by natural processes, while water retention is realized at the local level. In our study, we used the effluent of an intensive African catfish farm for irrigation. The farm uses thermal water for fish farming, which is characterized by a high sodium content. At the same time, the effluent is rich in organic matter and minerals. The planting of the willow plants in the study area, which is close to 3 ha, took place in the spring of 2014 with a variety candidate 'Naperti'. During the experiment, seven treatments were set up, of which one was non-irrigated, three were irrigated with the water of the Körös oxbow lake and three were irrigated with the effluent water. Three doses of irrigation water (15, 30, 60 mm) were applied to the one-week irrigation intervals with a microspray irrigation system. At the end of the growing season, samples of the plant parts (leaf, stem, root) were collected, during which mineral element analysis was performed with special regard to nitrogen, phosphorus, potassium, calcium, magnesium and sodium levels. The results of the study showed a significant difference in macroelements only for nitrogen for all plant parts. However, there was no significant difference in case of the mesoelements. In the case of sodium, compared to the leaf and stem plant samples, the root part accumulated a significant amount of salt, especially in the samples irrigated with 30 mm effluent water, where the Na content reached 521 mg/kg-1.