Dry beans give about 0.9-1.8 million kcal per acre and sunflower seed 1.3-2.6 million, so neither feeds many people per acre, but they supply protein and fat that grains and roots lack. Because a healthy diet needs 20-35% of its calories from fat, a community of 100 would need roughly 20-36 million kcal of fat a year, far more than the 3-5 acres of oil crops in the caloric guide’s sample plan can provide on their own.
Part of Caloric Budget for a Community
Legumes and oil crops are the dry beans, peas, lentils and oilseeds, such as sunflower, that supply a community’s protein and fat and restore nitrogen to the soil.
Low Calories Per Acre, High Value Per Calorie
The caloric guide’s sample plan for 100 people has 8-10 acres of legumes (dry beans, peas, lentils) and 3-5 acres of oil crops (sunflower, rapeseed). Its figures:
| Crop | Yield (lb/acre) | kcal per lb | kcal per acre (million) |
|---|---|---|---|
| Dry beans | 600-1,200 | 1,520 | 0.9-1.8 |
| Sunflower (seed) | 500-1,000 | 2,620 | 1.3-2.6 |
Working: beans 600 × 1,520 = 0.91 million and 1,200 × 1,520 = 1.82 million; sunflower 500 × 2,620 = 1.31 million and 1,000 × 2,620 = 2.62 million. The sunflower figure is for the whole seed; the oil that reaches the table is less. The corpus guide on Oil Extraction says hand-pressing recovers 50 to 70 percent of what a seed contains.
Legumes also fix nitrogen. The crop-rotation guide gives 50-200 kg of nitrogen per hectare through root nodules (Crop Rotation, Legumes), which is why they sit in the rotation and not only on the plate.
Worked Example: How Much Fat?
The oil-pressing guide states a healthy diet needs 20 to 35% of calories from fat (Oil Pressing at Scale).
- Per person per day at the 2,800 kcal community average: 0.20 × 2,800 = 560 kcal and 0.35 × 2,800 = 980 kcal. At 9 kcal per gram of fat (the corpus figure for plant oil), that is 62 g to 109 g a day.
- For 100 people for a year: 560 × 100 × 365 = 20.4 million kcal and 980 × 100 × 365 = 35.8 million kcal, about 36 million.
- If all of it came from whole sunflower seed energy at 1.3-2.6 million per acre, it would need 20.4 ÷ 2.6 = 7.9 acres to 35.8 ÷ 1.3 = 27.5 acres.
- The plan’s 3-5 acres of oil crops give 3 × 1.3 = 3.9 million to 5 × 2.6 = 13 million kcal of seed energy, before the 50-70% press recovery.
So the oil acreage covers only part of the fat target. The rest is meant to come from animal fat, dairy, eggs and the natural fat in the other crops. The 20-35% fat share comes from the oil-pressing guide, not from the caloric guide, so treat the gap as a reason to check the fat sources, not as a precise shortfall.
What You Need
- Legume seed suited to your climate, and inoculated or rotated soil (Bean Seeds)
- Threshing and drying space for dry beans
- A press for oilseed (Oil Extraction)
- Storage that keeps beans dry and oil cool and sealed
Method: Plan Legumes And Oil
Step 1: Allot legume acres in the rotation, 8-10 in the sample plan, and put them before grain. Step 2: Allot oil acres, then work out the actual oil recovery from your press and use that, not the seed energy. Step 3: Add the animal fat and dairy you expect, and compare the total with the 20-35% target. Step 4: Plan the cooking: beans need a long, hard boil.
Common Mistakes
- Planning oil calories from seed weight. The press leaves much of the oil in the cake.
- Dropping legumes when calories look low. They supply the protein and the nitrogen.
- Cooking beans like grain. See below.
Safety
Undercooked dried beans are poisonous
Soaked dried beans need a 15-minute hard boil in fresh water, then a long simmer, to destroy their lectin toxin (Grains & Legumes). Slow, low cooking can leave the toxin intact. Write this into every big-pot bean recipe.
What’s Next
- Learn next: Vegetables and Fruits as Supplements — the micronutrient crops
- Combine with: Dairy and Egg Calorie Efficiency — the animal fat side