When we think of protein foods we normally think of meat, dairy and eggs. However, we can also get protein from plants. Beans and grains contain the most, but there is some protein in all vegetables. Of course, if you depended on a plant-based diet for your protein, you would be wise to look to the concentrated plant sources for your needs, unless you are eating a really large amount of food.
Protein is used by the body for building and maintaining. It stands to reason if you are pregnant or nursing, or have been injured and need to repair tissue, your protein requirements would be higher than the recommended daily allowance of 46 grams/day for women and 56 grams/day for men. In my last post I talked about growing potatoes for needed calories. Potatoes have 7.7 grams of protein per pound, so if you ate a considerable amount of potatoes, you would also be racking up the protein. Carol Deppe spent a winter eating a lot of potatoes and wrote about it at http://caroldeppe.com/ThePotatoBin.html. On the other hand, if you ate corn and beans for protein, you would get about 40 grams of protein for each pound of corn you ate and over 100 grams per pound of dry beans. In addition to potatoes, Deppe grows her own beans and corn. If you are interested in growing a significant part of your diet, her book The Resilient Gardener needs to be on your reading list.
Protein is made up of amino acids, many of which can be synthesized by the body, if enough nitrogen (protein) is available. However, there are eight amino acids, referred to as essential amino acids, that need to come from the food we eat. Animal sources have all the essential amino acids and plant sources do not. Interestingly enough, the ones the legumes (peas and beans) are lacking are the ones that the grains have plenty of, and vice versa. There are reasons for the traditional meals such as cornbread and beans, tortillas with beans, and beans and rice. Even peanut butter on whole wheat bread serves to give you the right combination. Beans and grains don’t need to be eaten at the same meal to get the benefit, but they both need to be in your diet somewhere.
Besides protein and calories, including grains in your garden plan provides carbon in the form of stalks and straw for compost making, necessary for feeding the soil without bringing compost materials in. In my garden I have straw from wheat and rye in June and from cornstalks in the fall for compost. Besides the straw from wheat and rye, much organic matter is left in the soil from their decomposing roots. The legumes are soil enriching crops, leaving behind nitrogen for the next crop. The most nitrogen is left in the soil if the legume crop is harvested at flowering, as you would if you were growing it only as a compost crop. After that, nitrogen is put toward producing the beans or peas. Nevertheless, some nitrogen stays behind and it is good to have legumes in your rotation.
Other protein sources from your garden are peanuts and sunflowers seeds. I harvest peanuts before the frost kills the vines, hanging them in the barn for the peanuts to dry on the vines. I pick off the peanuts when they are ready. You can see that in my DVD Cover Crops and Compost Crops IN Your Garden. The vines become compost material, but that peanut hay could also feed small livestock. Peanuts and sunflower seeds contain 117.9 and 108.9 grams of protein per pound respectively. These crops also supply needed fat in your diet. In addition, they can be used for cooking oil. More information about that is at my post http://homeplaceearth.wordpress.com/2012/07/10/using-a-piteba-oil-press/. Sunflower stalks, like the cornstalks, are used in the compost.
In a permaculture garden you might have hazelnut (filbert) trees. Hazelnuts have 57.2 grams of protein per pound. My hazelnuts form a border on the north side of my garden. I wrote about hazelnuts at http://homeplaceearth.wordpress.com/2012/03/20/hazelnuts-filberts-in-my-garden/. Hazelnuts trees can be pruned, with the trimmings feeding your rocket stove. These nuts also provide fat in your diet and can be pressed for oil.
Okay, I know you aren’t going to be eating a pound of beans or corn at a meal. In terms more easy to understand, a cup of boiled cowpeas (the beans I grow) has 13.3 grams of protein. I use ½ cup cornmeal, cooked with milk or water for a good-sized serving of cereal. That cornmeal has 5 grams of protein. A thick slice of homemade whole wheat bread has 3.9 grams of protein. A one ounce serving of peanuts has 7.4 grams. By comparison, a cup of milk contains 8 grams of protein and one large egg contains 6.3 grams.
If you have enough calories in a varied homegrown diet, most likely you are getting enough protein. As you can see, growing grains for compost naturally gives you protein foods. If you were growing a significant part of your diet, you would also be concerned with having enough calcium. That’s the topic for next time.
More about Growing Protein at http://www.motherearthnews.com/permaculture/growing-protein.aspx.