Sorption Ability of Soil Improvers Based on Sapropel and Biochar to Mineral Fertilizer Nutrients

Abstract

Abstract The aim of this study was to determine the ability of soil improvers based on sapropel and biochar to adsorb macronutrients of mineral fertilizer. The composition of soil improvers varied in the volume ratio of sapropel and biochar. Sequential three-stage irrigation of various mixtures of sand and soil improvers after the application of mineral fertilizer was carried out using the column system. The content of mineral nitrogen, phosphorus and potassium in the filtrate and the initial mixtures was analyzed. The data on the dynamics of leaching out of ammonium and nitrate nitrogen from different mixtures (sand + soil amendment + mineral fertilizer) indicated that the most intensive leaching of NO3–N and NH4 – N occurred after the first irrigation. Increasing of sapropel content in the composition of soil improvers was correlated with the resistance to leaching out of mineral nitrogen from mixtures after irrigation. The ability of soil improvers to fix phosphorus increased in mixtures with the highest input of sapropel. Intensive leaching of potassium from soil improvers under irrigation was observed. Soil improvers with content of 90% of sapropel and 10% of biochar in case of its application into the sand in ratio 4:1 had the best sorption characteristic.