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GCB Bioenergy

Cover image for Vol. 9 Issue 5

Edited By: Steve Long

Impact Factor: 6.151

ISI Journal Citation Reports © Ranking: 2015: 1/83 (Agronomy); 9/88 (Energy & Fuels)

Online ISSN: 1757-1707

Associated Title(s): Global Change Biology

Optimizing nutrient sustainability in energy cropping

Sochacki - Optimizing nutrient sustainability in energy cropping In dry areas such as southern Australia, the replacement of native vegetation with agricultural systems has resulted in rising groundwater resulting in salinization. Phase farming with trees (PFT) provides an opportunity to produce bioenergy and restore landscape hydrology. Species selected for PFT have high water use and are planted at high densities in short rotation (3–5 years). PFT depletes soil water, which in turn reduces groundwater salinization allowing the return of agriculture. Biomass produced from PFT could then be used as a sustainable source of biomass for energy production. Yet, there is concern that soil nutrients may be removed along with the tree biomass during harvest.

Sochacki and coauthors studied the impact of tree species selection on biomass production and nutrient use. They planted three short rotation tree crop species at four densities and harvested them three years after planting.

In this study, the export of nutrients for a 3 year rotation bioenergy system did not detrimentally affect the nutrient status of the dryland farming system. The application of PFT in short rotations on agricultural land was not only sustainable, but potentially enabled the recycling of leached nutrients. Nutrient removal could be alleviated through the employment of different harvesting strategies, or the replacement of lost nutrients either by reapplication of biomass wastes after processing or through rotations of legume crops for nitrogen input.

Sochacki, S. J., Harper, R. J., Smettem, K. R. J., Dell, B. and Wu, H. (2012), Evaluating a sustainability index for nutrients in a short rotation energy cropping system. GCB Bioenergy. doi: 10.1111/j.1757-1707.2012.01202.x Read this paper.

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