Sustainable Urban Living: Green Solar Energy for Food and Biofuels Production - Design with the Desert: Conservation and Sustainable Development - page 413

Fertilizers
· Nitrogen
· Phosphorus
· Potassium
· Limestone
· Micronutrients

Equipment
· Tractors
· Trucks
· Harvesters
· Loaders
· Buildings
· Elevators
· Storage
· Work shop
· Electricity

Agricultural chemicals
· Herbicides
· Pesticides
· Fungicides
· Specialty chemicals

Fuel
· Oil
· Diesel
· Gasoline

· Labor
· Seeds
· Irrigation
· Transportation

FIGURE 24.1
Fossil inputs necessary for modern agriculture.

· 1 ac of fertile cropland

· 1 million gal of fresh water

2.5 tons of CO 2
pus NO x and smog

· 10 gal of diesel fuel

· 130 lb of nitrogen

Nutrients lost
to harvest and
erosion

· 60 lb of phosphorus

· 65 lb of potassium

· 450 lb of lime

· Herbicides and pesticides

6 tons soil
erosion

Fossil resource consumption

Unsaturated soil

Water table

with stored water

Polluted water

Freshwater aquifer
1 million gal of fresh water

FIGURE 24.2
Environmental impacts from modern agricultural practices.

These agricultural chemicals erode into the groundwater and enter human foods and
municipal water. The City of Des Moines, Iowa, ground zero for ethanol production, will
spend $455 million on water treatment to reduce agricultural pollutants from city water. 8
Urban centers throughout the West will have to follow suit because EPA studies show that
37% of U.S. lakes are unfit for swimming due to runoff pollutants. 9