Biodiesel production in New Zealand: Opportunities and considerations

Biodiesel is frequently promoted as an alternative ‘green’ energy source that could lead to fuel security for the transport and farming industries. However, the growing of such crops has been criticised for taking valuable arable land out of food production and thus, in fact, reducing food security. To mitigate these effects, it has been proposed that marginal soils be used for biodiesel crop production.
In this New Zealand study a diverse range of oilseed species were evaluated for biodiesel production on both high quality arable soils and on marginal land. On the marginal soils grain yield and oil production were low and variable, with Camelina (Camelina sativa) and canola (Brassica napus) out-yielding all other species tested. On the higher quality arable soils much higher yields were achieved, with canola out performing all other species tested.
In New Zealand, dryland marginal soils are primarily used for intensive sheep meat production or where irrigation is available, may have been converted to dairying; therefore the notion that these soils are not used for food production is simplistic. Changing farming systems on these marginal soils to biodiesel production would lead to increased farm risk. Alternatively, producing biodiesel from high producing canola crops on quality arable soils would likely provide benefits such as improved crop rotations and regional fuel security.