Potassium adsorption on substrates formulated with vermiculite and peat

The substrates composition can take place from different raw materials, being an influencer of the water and nutrient retention capacity, an important dynamic in the management of the cultivation in containers due to the possibility of nutrient leaching. It was aimed to quantify the Potassium adsorption to substrates with different proportions of vermiculite and peat, in addition to determining adsorption isotherms which would best fit the observed adsorption data, for contact periods of one and seven days. We carried out batch adsorption essays, using as an adsorbent media substrate prepared with different proportion of vermiculate and peat, and as adsorbate, solutions with concentrations of 0, 25, 50, 75 and 100 mg/L of K. The substrate that showed the highest adsorption capacity, then less leaching potential, was the one constituted with the largest amount of peat. The Freündlich’s isotherm best represents the K adsorption phenomenon in all the studied treatments.