The impact of activated carbon on NO₃--N, NH₄+-N, P and K leaching in relation to fertilizer use.

摘要

The ability of light-textured soils to retain nutrients and water is small. In agriculture such soils pose a risk of nutrient leaching when amended with fertilizers. This study investigated the effects of the incorporation of activated carbon (AC) into the soil to determine (i) if it would decrease leaching of major nutrient ions and (ii) if its effect on leaching is influenced by fertilizer use. Nitrate nitrogen (NO₃--N), ammonium nitrogen (NH₄+-N), phosphorus (P) and potassium (K) leaching through two substrates (sandy loam soil (S) and a sandy loam soil mixed with activated carbon (S+AC)), which were unfertilized (NF or control) or fertilized with inorganic fertilizer (F), pig slurry (PS), pig slurry digestate (PD) or sewage sludge digestate (SD) was studied using mini-lysimeters. In soil enriched with AC mark K-835, water percolation and NO₃--N and P leaching were significantly reduced, and K leaching was increased. Ammonium nitrogen leaching was not influenced by the AC amendment. The impact of AC on NO₃--N and P leaching and water percolation did not change during the two-year period, from which it is concluded that AC mark K-835 prevents the leaching of NO₃--N and P and increases soil water retention ability, and thus it is beneficial for light-textured soils.