Ash as a phosphorus fertilizer to reed canary grass: effects of nutrient and heavy metal composition on plant and soil

Abstract

Fertilization effects and risks of heavy metal enrichment were studied in a field experiment, in which plots of reed canary grass (RCG) were treated annually with three different fertilizers: Ash from co-combustion of RCG and municipal wastes (mixed ash), pure RCG ash, and commercial fertilizer (control). RCG ash is a waste product that is currently expensive to dispose of. The amounts of nutrients applied annually were 100 kg ha À1 N, 15 kg ha À1 P, and 80 kg ha À1 K in all treatments. In the ash treatments, all P derived from ash, whereas N and part of the K were supplemented by fertilizers. The amount of heavy metals exceeded the limits set by the Swedish Environmental Protection Agency for all elements analyzed in the mixed ash and for Ni and Cr in the RCG ash. There were no significant differences between treatments in terms of RCG dry matter yield obtained at harvest in spring, or in heavy metal concentrations in the biomass. Soil samples from 0-5 cm, 5-10 cm, and 10-20 cm below the surface showed significant differences between treatments for the concentration of Cd, Cr, Cu, Pb, and Zn, with higher concentrations in plots fertilized with mixed ash than in the control. Neither spring yield nor soil available P was reduced by using ash instead of mineral P fertilizer, suggesting that pure RCG ash can be used to complement commercial fertilizer, albeit less frequently than here. However, ash derived from co-combusting RCG with different waste materials (mixed ash treatment) should not be used in RCG production due to the high heavy metal content.

Environmental Application of Ash from Incinerated Biomass

“…The increased nutrient supply of the soil through the treatments was not reflected in the nutrient content of the plants during the first year [12]. In other studies [23], ash from reed canary grass could be used as a substitute of phosphorus fertilisers in the cultivation of this plant for energy purposes. The yield-stimulating effect of reed canary grass ash is comparable to that produced by commercial phosphorus fertilisers, although the biomass of crops contained more crude ash after the application of ash.…”

Reed Canary Grass for Energy in Sweden: Yields, Land-Use Patterns, and Climatic Profile

“…A database of existing trials was constructed, including records from RCG, willow, and poplar/hybrid aspen (given the limited area planted, in this paper, will be referred together). For RCG, trial records were retrieved from Landström et al [18], Lindvall et al [23], Nilsson et al [14], Lindvall et al [25], and Lindvall [21] during the period 1991-2015 (N = 201). For willow, a trial database was used based on Mola-Yudego et al [31] (N = 290) and for poplar, from Dimitriou and Mola-Yudego [32] (N = 58).…”

“…In recent decades, this has been changed to 40, 15, and 50 kg in the year of sowing; 100, 15, and 80 kg the following year; and 50, 5, and 20 kg in spring [22]. To reduce fertilisation costs, the application of mixtures of sewage sludge, wood, and grass ash have also been practiced [19,23]. Harvest takes place in the second year after sowing, preferably in early spring because the grass presents the lowest moisture content (ca.…”

Assessment and Characterization of Reed Canary Grass Plantations for Energy

“…A database of existing trials was constructed, including records from reed canary grass, willow, and poplar/hybrid aspen (given the limited area planted, in this paper will be referred together). For reed canary grass, trial records were retrieved from Landström et al [10], Lindvall et al [22], Nilsson et al [8], Lindvall et al [12] and Lindvall [19], during the period 1991-2015 (N=201). For willow, a trial database was used based on Mola-Yudego et al, 2014 [26] (N=290) and for poplar, from Dimitriou and Mola-Yudego, 2017 [27] (N=58).…”