The contribution of mineralization to grassland N uptake on peatland soils with anthropogenic A horizons

Abstract

Peatland soils contain large amounts of nitrogen (N) in the soil and mineralization can contribute substantially to the annual mineral N supply of grasslands. We investigated the contribution of N mineralization from peat with respect to the total annual N uptake on grasslands with anthropogenic A horizons and submerged tile drains. The study included i) a pot experiment to determine potential N mineralization from the topsoil and the subsoil, ii) a 1-year field experiment to study herbage yields and N uptake under fertilized and non-fertilized conditions and iii) a 3-year field study where herbage yield and N uptake from the top 30 cm and the entire soil profile were monitored. The 3-year field study yielded an average N uptake of 342 kgha −1 under non-fertilized conditions but the contribution of subsoil peat N mineralization to the total N uptake was found to be negligible. Our calculations demonstrate that peat N mineralization contributed only 10% to 30% to the total N-uptake, mainly coming from the top 30 cm. Most of the N uptake under unfertilized conditions appears to be largely the result of mineralization from long-term inputs of dung, ditch sludge, farmyard manure, cow slurry and non-harvested herbage.

Mineralization and herbage recovery of animal manure nitrogen after application to various soil types

“…These observations concur with those of Magdoff (1978) who concluded that soils with high soil N mineralization rates do mineralize N from added manure more rapidly compared to soils with lower inherit N availability rates. It should be noted that in our experiment the TNR values and net N mineralization potential of the peat soil could have been stimulated by the long-term (>50 years) high input rates of crop residues, ditch sludge and animal manures on the dairy farm where this soil was collected (Sonneveld and Lantinga 2010). This farming practice has led to a build-up of young soil OM including young organic N Fig.…”

Can the presence of plantain (Plantago lanceolataL.) improve nitrogen cycling of dairy grassland systems on peat soils?

“…The observed quadratic increase of plantain N yields at higher plantain DM yields partly confirmed our hypothesis that the presence of plantain can increase the N use efficiency of grassland on peat soil since on the other hand no effects of the presence and yield of plantain on ryegrass N yields were observed (Figure 2). In our experiment plant N contents were low (1.94 ± 0.32 g kg −1 DM) compared to field conditions (typically summer and autumn N contents without fertilisation are ≥2.40 g kg −1 DM) (Vellinga and Andre 1999;Sonneveld and Lantinga 2011;Deru et al 2019). Soil mineral N, P AL , K and pH conditions were not likely to have limited plant N uptake (CBGV 2017).…”

Short-term effects of biogas digestate and cattle slurry application on greenhouse gas emissions affected by N availability from grasslands on drained fen peatlands and associated organic soils

“…It is well known that drainage enhances the degradation of soil organic matter (SOM) and thus stimulates net nitrogen mineralization and N transformation processes (Kasimir Klemedtsson et al, 1997;Freibauer et al, 2004;Klemedtsson et al, 2005;Goldberg et al, 2010). Various studies reported an annual N supply through peat mineralization of 70 to 292 kg N ha −1 yr −1 (Schothorst, 1977;Flessa et al, 1998;Sonneveld and Lantinga, 2011). It can be assumed that at a comparable aeration status and temperature, mineralization processes are more intensive at peatlands that were recently drained (Hacin et al, 2001;Renger et al, 2002;Sonneveld and Lantinga, 2011) or contain higher amounts of SOM.…”

“…Various studies reported an annual N supply through peat mineralization of 70 to 292 kg N ha −1 yr −1 (Schothorst, 1977;Flessa et al, 1998;Sonneveld and Lantinga, 2011). It can be assumed that at a comparable aeration status and temperature, mineralization processes are more intensive at peatlands that were recently drained (Hacin et al, 2001;Renger et al, 2002;Sonneveld and Lantinga, 2011) or contain higher amounts of SOM. As expected from the literature, the biogas digestates differed in their physical and chemical properties from the cattle slurries.…”