Yield per hectare (measured in Grain Equivalant):
* Africa 1,5 tons
* World 3,5 tons
* Europe 6,5 tons
* Netherlands 9 tons
These differences are largely due to the use of fertilizers (crop -genetical- modification must have an effect). Without the use of chemical fertilizers the average yield would be 2 tons GE.
A typical vegetarian consumes 1.5 kg of Grain Equivalents (GE) per day.
A typical European diet consists of 4,5 kg of GE.
There is not enough available land to consume a European diet without using chemical fertilizers.
On biofuels:
"The fundamental point is that plants fix only 2.5 percent of the solar energy they capture, which makes the conversion of solar energy through biology highly inefficient. Biofuels put a very large claim on productive land and water resources that will ultimately compete with food production. Because of additional claims on land, loss of biodiversity is inevitable and emissions of greenhouse gases may exceed those of fossil fuels."
We can reduce fossil fuel use, but we need chemical fertilizer
