now everything is grown on nutrient devoid soils
It doesn't matter all that much, since the plants, you know, synthesize stuff. If there isn't enough nitrogen in the soil, the yields will be poor, but it's not like you'll get nitrogen-deficient plants. They'll be plant-matter-deficient in general. So talking about "nutrient devoid soils" is quite pointless: it only affects the yields, not the nutritional value of the end product. There'll be less stuff, smaller bulbs or fruit, etc. At least that's my high-school understanding, plant biologists please correct me.