Short-term effects of liming and vitality fertilization on forest soil and nutrient leaching in a Scots pine ecosystem in Norway

Abstract

The effects of liming and vitality fertilization on soil acidity, base cations and nutrient leaching were examined after four growing seasons in a Scots pine ecosystem in southern Norway. A randomized block field experiment was established in 1992 on a sandy, well drained, fluvial plain with a weakly podzolized soil (Cambic Arenosol). The Scots pine ( Pinus sylvestris L.) stand was by then 33 years old at breast height and had a medium site index class. The treatments consisted of a single application of 3000 kg lime or dolomite per hectare, or 6000 kg dolomite ha −1, and some of the plots were also fertilized with a combination of various amounts of KCl, superphosphate, kieserite, NH 4NO 3 or borax. In 1992 before the liming, the forest soil examined was highly acidic and nutrient-poor with fairly low reserves of exchangeable Mg and with a high pool of exchangeable Al. The most distinct liming effects such as an increase in soil pH and base saturation took place in the humus layer, where the highest portion of applied Ca and Mg was recovered. The treatment effects of lime were most evident, and these have spread more deeply into the soil than the effects of dolomite. The fast-release fertilizers increased the pools of exchangeable K and Mg down to at least 22 cm soil depth for the optimal treatment (no. 6), while the soil pH dropped 0.2 units in the upper part of the mineral soil. The pool of easily soluble P increased in the humus and eluvial horizon for this treatment too. A relatively small part of the added K and nearly half of the P addition could be recovered in the soil, while the B retention was very low. A great part of the applied N had been incorporated in the soil organic matter. There were clear treatment effects on the soil solution concentrations below the main root depth (80 cm) for all measured elements, except Al. About one-fourth to one-third of the highest added amounts of N, K, Mg, S and B were leached and slightly more than 10% of the added Ca was leached. The leaching was driven by the leaching of the anions of N and S.