Possible species for the production of biodiesel on marginal land

A series of field experiments was conducted in 2009-10 and 2010-11 in the North and South Islands of New Zealand to examine the potential of brown mustard (Brassica juncea); camelina or false flax (Camelina sativa); meadowfoam (Limnanthes alba) and field penny-cress (Thlaspi arvense) with oilseed rape (Brassica napus) as the current NZ biodiesel crop. Crops were grown at three sites in both years; Ashley Dene (dryland sheep farm, Lincoln), Oxford (wet, low fertility land in the foothills of the Southern Alps) and Taupo (central North Island light pumice soil). There were both autumn and spring sowings at all sites in 200910, but in 2010-11, Taupo and Oxford had spring sown trials only. In 2009-10 all species established well after sowing with the exception of field penny-cress. At Taupo and Oxford oilseed rape yielded up to 2.3 and 3.8 t seed ha(-1) respectively, but at Ashley Dene it yielded less than 1 t seed ha(-1). Brown mustard and camelina performed nearly as well at some sites, producing up to 2.9 t seed ha(-1) at Taupo, yet at Ashley Dene, camelina produced just 0.9 t seed ha(-1). Meadowfoam had the highest seed yield of nearly 1.6 t ha(-1) at Ashley Dene, and, at Taupo and Oxford, it yielded up to 1.0 and 0.6 t seed ha-1 respectively. Seed oil contents within species were similar across all sites. Oilseed rape had the highest oil content, averaging 40% followed by brown mustard (35%) and camelina (33%). Field penny-cress and meadowfoam were lower, averaging 24% and 15% respectively. Oil yields followed a very similar trend to seed yield. Maximum oil yields of 1.5 and 1.0 t ha(-1) were attained by oilseed rape at Oxford and Taupo respectively. Most other sites, sowings and species combinations produced less than 600 kg oil ha'. In 2010-11 the crops were much less productive than in the previous year. This was mostly due to weather events- significant late rainfall at Taupo causing disease problems and destruction of bird netting by high winds in Canterbury allowing birds to eat the seeds. As a consequence, oil yields were less than half of the previous year in those sites. The maximum oil yield was 967 kg ha(-1) from oilseed rape sown in September at Oxford. This study has shown the adaptability of oilseed rape to marginal environments and the potential of camelina as an alternative biodiesel crop.