Here you will find a Nature article on field edges, and an experiment. The results may surprise you. I will quote the abstract, which is enough.

Setting aside some farmland as wildlife habitat might not reduce crop yields.

Richard Pywell at the Natural Environment Research Council’s Centre for Ecology and Hydrology in Wallingford, UK, and his team studied 56 fields at a farm growing wheat, oilseed rape and field beans over 6 years. Along field edges, 0%, 3% or 8% of the total cropped area was set aside as habitat for birds, pollinators and other wildlife. None of the crop yields in the three experiments decreased, despite the difference in crop area. In fields without any habitat set aside, yields at the edges were poor, whereas in fields with habitat margins, the wildlife seemed to boost yields by increasing the productivity per unit area.

For beans, the yield was 35% higher in the fields where the most land was set aside.

The article is dated October 2015. I have a Nature subscription and was able to find it. What made me want to look was a more recent article (also in Nature) about crops in marginal land in Africa.

Planting trees (acacia, I think) amongst the crops increased yields in soils that were depleted, often from overgrazing. The trees made leaves in the rainy season, and dropped them, fertilizing the crops with carbon and fixed nitrogen.

Another strategy was to mix in other plants: ones that grew later than the legumes, for example, in the midst of the main crop. These were anti- to boring insects. At the edges, another plant which attracts borers, and later traps their larvae in sap. Both these plant types could be used for animal fodder. On alternate seasons, maize could be grown instead of legumes.

The effect was to greatly increase yield on what was poor soil, from a tenth of the ideal yield in North America, to three times that.

So, what’s my point? My point is that, our huge agribusiness farms are not the most efficient in terms of crop yield per acre. I suspect they are optimized for cash yield per acre, which takes into account human labour costs and the lost time moving from one small field to another.

I also think studies have shown that fields in North America that have margins with ‘wild’ plants growing there, have better pollination and are more robust against insect pests.

Of course, nothing will change. Facts don’t matter, only profit does. This in a world where even our own people often go hungry. Something like 80,000 food bank visits per month in Toronto (central) alone.

So, now for the mandatory dumb questions.

Could we use more food production, if it were affordable to the poor?

Are the African countries facing tough conditions more able to adapt than we are?

Is this because our agribusiness is more or less concentrated, whereas in Africa it is still relatively small farms for most of the cultivated area?

(I must note that, when the African farmer does not own the worked land , he or she is less likely to invest in its replenishment. This is, imho, the problem with slum housing here as well, but that’s an entirely other post for a different day, eh?)

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