Boron in irrigation water and its interactions with soil and plants: an example of municpal landfill leachate reuse

Abstract

In several countries, leachate is successfully treated by recirculation to the vegetated landfill cover, as it contains several micro and macronutrients for plant growth. However, the proportion and concentration of some parameters can negatively affect the plant growth and soil quality in the case of high leachate input. The presented research discusses B in leachate and its interactions with soil and plants. A ten-month field research was performed on 1.1 ha of the closed and covered municipal solid waste landfill site irrigated with landfill leachate. B concentration was analysed in leachate, landfill soil cover and in plant leaves. Total B concentration in leachate ranged from 0.8 to 3.83 mg/L. Monthly B mass load on the covered landfill site ranged between 0.2 – 1.5 kg/ha. The concentration of bioavailable B in soil cover gradually increased and ranged between <0.5 – 2.75 mg/kg dry weight soil. The average total B concentration in clover leaves was 23.9 mg/kg, in grass leaves 4.5 mg/kg, in the leaves of younger willows in the new part of the landfill cover 41.3 mg/kg and in the leaves of the older willows in the old part of the landfill cover 81.8 mg/kg. Leachate application increased plant growth during the observation period and there were no toxic effects on plant leaves, although B concentrations were higher compared to usual concentrations found in natural environment.