Abstract

Combusted reed canary grass (RCG) produces relatively high amounts of ash. Deposition of large amounts of ash is both costly and may cause environmental problem. Alternatively RCG ashes can be seen as a resource of nutrient elements that can be recycled as fertilizer in agriculture. A field trial was established at SLUs field station in Umeå in the spring 2002 to asses the risk of enrichment of heavy metals using annual ash applications. Three different treatments were applied: Ash from combustion of RCG together with municipal wastes (A), ash from RCG (B) and commercial fertilizers (C). The concentrations of plant nutrients and heavy metals are shoved in Table 1. The yearly applied amounts of nutrients were 100 kg ha-1 N, 15 kg ha-1 P and 80 kg ha-1 K. The amount of ash in treatments A and B was calculated to be equal to the required amount of P while the required amounts of N and K were complemented by commercial fertilizers. The trial was harvested each spring 2003-2009. There was large variation in dry matter yield between years but no significant differences between treatments were found. We also found no significant differences in heavy metal content of the grass between treatments. The grass content was lower for most elements in 2009 than in 2004, only Zn showed a significantly higher level (p<0.05). Soil samples from 3 levels; 0-5 cm, 5-10 cm and 10-20 cm showed significant differences between treatments for Cd, Pb and Zn only in the uppermost level (Table 2), with higher contents in treatment A. The differences between levels were mainly small, and compared to samples from 2003, there seems to be no tendency to enrichment during this period of time. In conclusion, the ash we used did not negatively affect the growth of RCG and can be used as a complement to commercial fertilizers, but ashes from mixed combustion need to be analyzed for heavy metals before use. Table 1. Concentration of P, K, Mg, Ca, S and heavy metals in the ashes used in the experiment. A = ash from combustion of RCG together with municipal wastes, B = pure RCG ash. Table 2. Concentrations of trace elements in top soil (0-20 cm) in spring 2003 and the uppermost level (0-5 cm) in spring 2009. The upper limits for soil content, when it is allowed to spread sewage sludge, are issued by Swedish Environmental Protection Agency. Means with different letters differ significantly between treatments, p<0.05

Keywords

Ash fertilization, reed canary grass

Published in

NJF Report
2011, pages: 166-166
Title: Book of Abstracts of the 24th NJF Congress Food, Feed, Fuel and Fun Nordic Light on Future Land Use and Rural Development
Publisher: Nordic Association of Agricultural Scientists

Conference

24th NJF Congress, 2nd Nordic Feed Science Conference- Food, Feed, Fuel and Fun, Nordic Light on Future Land Use and Rural Development

SLU Authors

• Lindvall, Eva

  • Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences
    

• Palmborg, Cecilia

  • Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Renewable Bioenergy Research


Permanent link to this page (URI)

https://res.slu.se/id/publ/41717