I got these numbers from the USDA 2014 Agricultural Overview. I aggregated them willy-nilly and even rounded to make the addition easier. This is rough; it won’t even add up to 10 million acres. But the next time someone says ‘California grows HALF! the countries fresh vegetables and fruit’, you can say, ‘yes, and they grow that on about one-third of their irrigated acreage. So we could stop irrigating the other parts with no loss to American salads.’
The 2014 California and Nevada Vegetable Crop Summary tells me:
The top 24 fresh market vegetables: 1.58 million acres
The top 8 processed vegetables: 1.09 million acres
The rest of these values are from the USDA 2014 Agricultural Overview:
Citrus: 271,000 acres (oranges: 170,000, lemons: 46,000, grapefruit: 10,000, tangerines: 45,000)
Fruit: 217,000 acres (peaches: 44,000, prunes: 48,000, melons: 56,000, cherries: 33,000, nectarines: 21,000, apples: 15,000)
Rice: 434,000 acres
Grapes: 880,000 acres (wine: 570,000, raisin: 200,000, table: 110,000)
Corn: 520,000 acres (420,000 acres silage = fed to cows)
Hay: 1,380,000 acres (alfalfa: 875,000 acres, other hay: 500,000 acres)
Nuts: 1,365,000 acres (almonds: 860,000 acres, pistachios: 215,000 acres, walnuts: 290,000 acres)
Last year’s drought resulted in fallowing about 500,000 acres.
You can add those up in different ways, but the fresh produce that humans eat directly (both veggies, citrus, fruit, table grapes) comes to 3,300,000 acres. That is one third of our irrigated acreage. We can round up to 4 million acres to get the small specialty crops. Sixty percent of California’s acres could drop out of production, 6 million acres, with no loss of fruits and vegetables. The rice is directly consumed by humans. Then about 2 million acres of corn, alfalfa and other hay is fed to animals. Then we grow nuts for the world.
I list these numbers to refute the implicit argument that goes: California grows half the country’s fruits and veggies and therefore must get enough water to irrigate all the land in production now. If the important thing is having fresh produce, we do that on about forty percent of currently irrigated land. After that, I believe there are policy choices to be made about whether we want to use water to make wine, keep the price of meat and dairy low, or grow nuts for the world.