Mainstreaming Biodiversity for Improved Food Security and Better Nutrition.
As someone who began addressing this same challenge in 1976, I have mostly seen over the decades an increase in the simplification of agricultural landscapes. The reasons for simplification are due to a complex web of factors but the challenge remains at farm level: how to encourage households who at one time had resilient, climate-smart, nutritionally rich, biodiverse farming systems to once again rebuild their biodiverse structure to meet their daily food and income needs. It may be doable if the will is there at all levels in the decision making process.
On a practical note, FAO's 1990 publication, "Improving nutrition through home gardening - A training package for preparing field workers" remains one of the top field guides on how to close dietary gaps, improve nutrition and food security through biodiversity, especially in the home lot.