GCTV18: AGFACE Pt2 - The Trial

Horsham, Victoria, site of Australia's Ag Face project. It's 1 of 7 free air carbon dioxide enrichment projects taking place around the globe. In part one of agface, we saw how this Australian experiment is the only Face project where agricultural crops are grown under dry land farming conditions. What's common to all the projects is the level of CO2 being applied to the crops. 50 parts per million, the equivalent of levels forecast for 35 years from now. The methodology is to apply CO2 through octagonal rings in the field and that's released upwind and it mixes across the crop. In a small area, a mother tank of carbon dioxide supplies the crop rings. How much CO2 and how often it's released from the upwind sections of pipe is controlled from the centre of each plot to plants. CO2 is food. Give them more and it's like adding fertiliser. What we've seen to date is that consistent increase in biomass and yield around 25%. It varies between cultivars and we're still working out which ones are better. And there's a whole suite of cultivars being tested and breeders lines also being tested here. Agface is a joint venture project between the Victorian Government and the UNI of Melbourne, with funding support from grdc. For about a decade, the research team has been collecting data from this paddock. And while the fertiliser effect of enriched CO2 levels is a positive, there are challenges as well. The plant's greater biomass will effectively dilute plant nutrients, including nitrogen, resulting in a loss of protein. That was a very big surprise in this experiment. The view was that we could fix that with fertiliser, but we're unable to do that. And so we're trying new ideas of fertilisers with inhibitors as well. The challenge is to figure out how this may be modelled and extrapolated elsewhere. And what might the mechanisms be that we could select parents that have higher quality grain. It's one of many lines of investigation in the Ag Face project. However, not many face projects have given crop modelling the importance it's received. In Horsham, homegrown and international modelling programs have been put through their paces. It really surprised us how good the models are. We've tested four Australian models here, they line up pretty well. And two overseas models, they're also pretty good. And so basically from all those models you come up with the same conclusions if applied here in Horsham. But there are still some issues with the models. They're all not the same and some models give different responses to temperature and that high temperature issues are the current focus going on around the world with the CO2 modelling is allowing the AgFace team to look even further into the future. And the final part of our story has a very surprising forecast for cropping country.