I understand the solar ammonia power station will be built at Whyalla Australia near where a 120 ML/day (31m US gall) desal plant will be built for Olympic Dam mine. It's supposed to be a joint project between two unis I've hung around. Even if they crack 20 MW that's peanuts compared to what's going on in the area so it really needs to impress.

I think for 2000 acres large compost bins the size of swimming pools need to be set up. Throw in everything ... macerated garbage, dead animals, worms, waste, weeds. When it is ripe stir in $20 of synthetic urea. Enjoy, plants that is. Or maybe inject the N-rich 'tea' into irrigation water then keep the leftovers for a smaller acreage.

Note that the demand for plug and play replacements in a given agricultural system are medium term rather than long term ... if replacement of grain monoculture with the mixed culture with nitrogen fixing plants grown side by side with nitrogen hungry plants cannot be managed with one farmer per 2,000 acres (800ha), then smaller farms may be required. That kind of transition cannot occur in a couple of years, but it clearly can occur in a couple of decades, given the changes in farm size we have seen in our history.

The thing about longer time scales, of course, is that it becomes far harder to project ahead with any confidence, which increases the importance of investing in multiple solutions to long term problems.