Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Abstract Only
Publication Acceptance Date: 7/22/2003
Publication Date: 10/12/2003
Citation: Chaney, R.L., Li, Y., Angle, J.S., Roseberg, R.J., Brewer, E.P. 2003. Development of a new crop, alyssum murale, for phytomining ni from contaminated or mineralized soils. p. 17 in Proceedings of the Association for the Advancement of Industrial Crops. (October 12-15, 2003, Portland, Oregon). Interpretive Summary: Based on the experience to date, Viridian LLC initiated commercial contracts for production of Alyssum murale on serpentine soils in several locations in OR and CA, and on smelter-contaminated soils near Port Colborne, Ontario. Especially cold tolerant germplasm was used in the Canadian production location, and tillage adapted to the poorly drained soils by ridge-tilling the field and providing adequate drainage. A recurrent-selection breeding program has been conducted for about 5 years with clear improvement in the plant for this use.
Technical Abstract: Certain rare plant species called Ni-hyperaccumulators contain over 1% Ni in dry shoots when grown on Ni mineralized or contaminated soils. Because Ni metal sells for about $8.75/kg, and plants could phytomine about 400 kg Ni/ha-yr, it seemed possible to develop a new commercial crop for northwestern US serpentine soils naturally rich in Ni. Co in the soils could be phytomined after Ni has been largely removed. This talk will summarize the development of the crop and management practices, obtaining patents, and commercialization of the technology in OR and Canada. After examining all species reported to be Ni hyperaccumulators, the team selected several species for development. Seed were collected for some germplasm and initial work completed which justified an Utility Patent for Ni phytomining. Then diverse germplasm was collected to breed improved cultivars for production on serpentine soils in OR and CA, and separately in Ontario, Canada. All nutrient requirements were established by experiments. The species Alyssum murale was developed most. This species occurs naturally across southern Europe wherever serpentine soils occur. By collecting seed from different eco-niches, and testing their growth potential and Ni accumulation potential in replicated field plots in Josephine Co., Oregon, we were able to demonstrate the probability that a commercial crop could be introduced. The plant is highly adapted (endemic) to serpentine soils that are very low in Ca and P fertility, and contain high Mg and Ni levels. The plants accumulate Ni to defend against plant diseases and chewing insects. Because the plants were adapted to serpentine soils, they were able to obtain adequate phosphate for full yield with only small P fertilizer applications. One of the most surprising outcomes in our research was that acidification of the soil (which increased soil Ni solubility) decreased Ni uptake to shoots; and for some soils lower in Fe, liming increased Ni uptake even though solution Ni dropped. Normal hay making equipment could be used to harvest the crop. Baled biomass can be burned to produce a Ni-rich ash that can be sold as a high grade Ni ore, and the biomass energy. A test of Ni recovery from the biomass ash was conducted at the Inco Ltd. smelter in Sudbury, Ontario, Canada, with easy recovery of the Ni for sale.