GCB Bioenergy

Cover image for Vol. 7 Issue 3

Edited By: Steve Long

Impact Factor: 4.248

ISI Journal Citation Reports © Ranking: 2013: 2/79 (Agronomy); 12/83 (Energy & Fuels)

Online ISSN: 1757-1707

Associated Title(s): Global Change Biology

Nitrogen increases prairie diversity and productivity

Jarchow - Nitrogen increases prairie diversity and productivityTraditional sources of feedstock for ethanol production such as corn are not considered to be environmentally sustainable. Production of monocultures homogenizes the landscape and results in environmental damage by degrading soil carbon stocks, fertility, and long-term productivity. In contrast, the use of perennial prairie as a bioenergy feedstock is touted for its numerous ecosystem services and potentially high biomass production. Previous studies have shown that diverse prairies would provide numerous ecosystem services including more habitats for wildlife and beneficial insects, and decreased nitrogen, phosphorus, and sediment movement into water bodies.

To date, assessments of the feasibility of using prairies for bioenergy production have focused on marginal areas with low yield potential. Growing prairies on more fertile soil or with moderate levels of fertilization may be an effective means of increasing yields. However, increased fertility often reduces plant community diversity.

Jarchow and Liebman explored how nitrogen fertilization affected the diversity and productivity of a prairie community used for bioenergy production. Over a 3 year period, they measured aboveground biomass production and characterized plant community composition in prairie systems that were harvested annually. The experimental plots received either no fertilizer or 84 kg of nitrogen per hectare per year.

The authors found that aboveground biomass production was 24% to 44% higher in fertilized compared to unfertilized prairies. This finding was in contrast with most previous research, which found that nitrogen fertilization reduces prairie diversity, nitrogen fertilization did not reduce prairie diversity in this study.

The authors caution that the timing of the application of nitrogen fertilizer and biomass harvest are likely to influence their effects on diversity. They conclude that proper management of prairies for bioenergy production may be an effective means of increasing production while maintaining environmental sustainability.
Jarchow, M. E. and Liebman, M. (2012), Nitrogen fertilization increases diversity and productivity of prairie communities used for bioenergy. GCB Bioenergy. doi: 10.1111/j.1757-1707.2012.01186.x Read this paper.

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