In my last post I wrote about how many more calories you could get if you grew beans and corn out and harvested the dried seeds. If you really wanted to grow a lot of calories in a small space, however, you would take a look at potatoes. The low Biointensive yield shown in the Master Charts of How To Grow More Vegetables (HTGMV) by John Jeavons is 100 pounds per 100 ft². There is an average of 349 calories per pound in potatoes—a little more in russets and less in white potatoes, with red-skinned spuds in the middle. If you were really hard-core in growing your calories, I suppose you would grow the russets at 358 calories per pound rather than the whites at 318, but I don’t care for the russet varieties as much as the others. A yield of 100 pounds, which is the best yield I’ve had, would give you 34,900 calories per 100 ft² bed. Comparing it to the corn that I talked about in that last post, with flour corn at 18,216, potatoes would give you 1.9 times the calories. Looking at the beans, with dried beans at 6,152 calories per 100 ft², growing potatoes would give you 5.7 times the calories in the same space.
In order to get all your calories from potatoes, however, you would have to eat many more pounds of potatoes than either beans or corn. To reach 2,000 calories per day, you would need to eat 5.7 pounds of potatoes, 1.2 pounds of flour corn, or 1.3 pounds of dried beans. Your calorie requirements might even be more than that, depending upon your age, sex, and lifestyle. The weight of the corn and beans is the dried weight. When considering the eating, multiply by 3 for the cooked weight, unless it is made into bread and tortillas, then multiply by 2. Hopefully your diet will be more diverse that just potatoes, corn, or beans, but this is how they would compare.
A man once told me that in survival training in the military, he was told that you could get everything you need from a diet of potatoes and milk. According to nutrition charts, a diet of too many potatoes could be toxic in potassium. On the other hand, if you need potassium, eat more potatoes. Having fermented foods, such as sauerkraut, in your diet would help rid your body of toxins. I think it was in the book Nutrition and Physical Degeneration by Weston A. Price that I read that the people he met in the mountains of Peru ate mostly potatoes dipped in a “gravy” of kaolin clay. The clay would have helped rid the body of toxins. It depends on the soil, climate conditions, and how it is grown, whether a food has certain nutrients or toxins in it. Studying indigenous diets is important if you want to grow all your own food. Our culture has lost some of the practices that were important in bringing food to the table. Sometimes they are the key we need to be successful in our endeavors.
Sweet potatoes are another good calorie crop. They might yield a little less per bed, but have a little more calories per pound. At the low biointensive yield that would mean 30,750 calories per 100 ft². In HTGMV Jeavons designates crops as area-efficient if they produce significant calories per area and weight-efficient if the amount that needs to be eaten for all one’s calories is 9 pounds/day or less. Of course, potatoes head the list of crops that are both area-efficient and weight-efficient. Other crops on the list besides sweet potatoes are Jerusalem artichokes, garlic, leeks, parsnips, and salsify. The information about area and weight efficiency for these crops is in HTGMV and is available online at http://www.growbiointensive.org/grow_main.html.
You might not be growing all your food, but putting a hearty meal on the table occasionally that consists of only food you have grown is pretty satisfying. Check out my Homegrown Friday posts to see some of my experiences on that in 2011 and 2012. If you have done something similar, by all means, add a comment and tell us about it.
It is good to know what to grow and prepare that will fill you up. There are so many factors to consider when planning your diet around what you grow. You want to make sure it is a sustainable diet, so while you are growing crops for high yields in some things, you are also growing crops that will feed back the soil. That’s where the grains come in. They are weight-efficient, but not area-efficient when it comes to calories, but they produce a lot of necessary carbon for your compost making. The beans, also, are weight-efficient and not area-efficient. You could, however, grow pole beans up the corn stalks and that would up your yield of calories per 100 ft². Beans and grains pair well together to provide the necessary amino acids that make up protein. I’ll talk about growing protein in the next post. See you then!
More about Growing Calories at http://www.motherearthnews.com/permaculture/growing-calories.aspx.