Question: When and how can we simultaneously deliver increased yields and reduce the environmental impact of agriculture?

Oli Wilson answered on 8 Nov 2017:

Person-with-potentially-my-favourite-ever-name, this is an absolutely amazing question. In recent history we’ve done really really well at increasing the agricultural yields – Earth has never, ever had as many human inhabitants as it does today (tomorrow will probably be another record too) and the fact that huge portions of them aren’t literally starving to death is a bit of a miracle. Both the population increase and the fact farming can support them is due largely to the Green Revolution that happened less than 100 years ago, introducing technologies like specially-bred crop varieties, chemical fertilisers, irrigation and mechanical help for farmers. But, as you seem to know, that probably won’t be enough for the future.
One thing we’ll have to do is to address a looming crisis in soil fertility – we’re running out of artificial fertilisers and it’s possible soils around the world will get less productive over time. That would be a nightmare, but legume crops (which can fix nitrogen into fertiliser) and smart use of soil microbes might increase fertility again, and there are simple things we could do to stop soil loss too. I suspect GM crops will be a big part of agriculture in the future – quickly increasing yield, environmental hardiness and health benefits of the crops that are being grown would be a great help.
Something that might help with both yield and environmental impact is encouraging local alternatives to global crops. Maize, for instance, is grown around the world even in places that aren’t particularly suitable; there might be local crops that are a better fit for conditions and which offer a more healthy rounded diet too. (This guy seems to be doing something right: http://www.huffingtonpost.co.uk/dan-griffin/there-is-an-alternative-t_1_b_1732002.html) That said, increasing agricultural output seems to be almost always bad for the environment – if you spread the effects out you could affect a huge area, but if you intensify it in a smaller space that place suffers enormously…
I really don’t know how and whether we can balance these two hugely important priorities. I’m glad that people smarter than me are working on it though – you might be interested to look at this report from the UN that looks (briefly) at the subject: http://www.fao.org/3/a-i6644e.pdf
Sorry for the massive answer, but it’s a pretty massive question! Do you have any ideas??