Few people realize that, if any disaster collapses our current agricultural production system, we will need to rebuild our supply of seeds for planting crops — the main commercial supply and also the seeds for gardens and small local farms. There are lots of small seed companies, catering to backyard gardeners. But the vast majority of the seed supplied for most of our agricultural land comes from just a few large agribusinesses. If some type of natural or man-made disaster collapses the commercial agricultural system, those few companies might not be able to provide seed. So this post looks at ways to rebuild the seed supply, starting with limited resources.
In 2013, the U.S. produced 1.85 million metric tonnes (MT) of wheat for seed. That’s not wheat for human consumption, but only the wheat used to plant the next year’s crop. Suppose we start with a certain modest amount of wheat seed. How do we produce 1.85 million MT of seed to plant a crop of wheat to feed the nation?
The seeding rate is determined by the number of seeds needed per area of land, and the weight of each seed. A large heavy wheat seed, like Kamut, has a high seeding rate, because each seed is larger and heavier. A variety of wheat with smaller seeds has a lower seeding rate, at the same number of seeds/plants per hectare, because each seed is small and light. A typical mid-range seeding rate for wheat would be 100 kg of seed per hectare of land. A hectare (ha) is 2.47 acres of land.
A grow-out is the planting of a crop solely to produce seed for a subsequent planting. How many grow-outs would it take to produce 1.85 million MT of wheat seed? If we start with 1 MT (1000 kg) of wheat seed, we can plant wheat at a seeding rate of 100 kg/ha. This will result in 10 hectares of planting, and a yield of about 3 MT/ha (a modest attainable yield), for a total first crop of only 30 MT. We need 1.85 million MT. The next grow-out gives us another 30 times increase in wheat for 900 MT. Several successive grow-outs are needed:
1: 1 MT plants 10 ha and produces 30 MT of wheat
2: 30 MT plants 300 ha and produces 900 MT of wheat
3: 900 MT plants 9,000 ha and produces 27,000 MT of wheat
4: 27,000 MT plants 270,000 ha and produces 810,000 MT of wheat
5: 810,000 MT plants 8.1 million ha and produces 24.3 million MT of wheat
Then in the sixth planting, only a portion of the seed needs to be used:
6: plant 1.85 million MT of seed to reach usual U.S. wheat production quantity: ~58 million MT of wheat for food
Part of the 5th harvest can be used for food, and the rest for seed. If we grow two crops of wheat per year, not necessarily on the same land, we don’t have food or enough seed for a full harvest until the sixth crop, which is in the third year.
Rebuilding the wheat seed supply takes three years, assuming we have the resources to plant and harvest each crop, and the will power not to use any of the harvest from the first four crops for food. Yikes! Not good news. But is there any crop that we can grow-out quicker? Yes.
A conservative seeding rate for amaranth is only 1 kg per ha, and a conservative estimate of yield is 1 MT (1000 kg) per ha. The increase is 1000-fold per planting, compared to an increase of only 30-fold for wheat. How does amaranth achieve this feat? By having many small seeds in a single kilogram, and by producing many seeds (grains) on each plant.
If we start with one MT (1000 kg) of amaranth for the first planting, we can plant 1000 ha instead of 10 ha for wheat. And with a yield of 1 MT/ha times 1000 ha, we achieve one thousand MT of amaranth (1 million kg) from the first crop.
1: 1 MT plants 1000 ha and produces 1000 MT of amaranth
2: 1000 MT plants 1 million ha and produces 1 million MT of amaranth
3: Then in the third planting, we can’t even use all the amaranth from the second planting for seed — 1 million MT would plant 1 billion ha, but the U.S. only has 400 million ha of agricultural land. So in the third crop, we can plant as much land with amaranth as we like, and produce as much grain amaranth for food as we like, with plenty left over to use as seed for the next year, or to sell to other nations.
Instead of 6 plantings to grow enough wheat, we need only three plantings of amaranth. This cuts the time to rebuild the seed supply from three years to 1.5 years, and we would have some amaranth leftover for use as food when the second harvest in the first year is completed.
The math for quinoa works out nearly as well, although quinoa seeds are larger, and so the seeding rate is higher. A typical seeding rate is 4 kg/ha, and a conservative value for yield is similar to that of amaranth, about 1,000 kg/ha (1 MT/ha). So a grow-out of quinoa would multiply the amount of seed by 250-fold with each crop — not as good as amaranth, but far better than wheat.
1: 1 MT plants 250 ha and produces 250 MT of quinoa
2: 250 MT plants 62,500 ha and produces 62,500 MT of quinoa
3: 62,500 MT plants 15.6 million ha and produces 15.6 million MT of quinoa
4: And then that 15.6 million MT of quinoa is more than you could ever plant for a subsequent grow-out. So part of that harvest would be for food, and the rest for seed. By the fourth crop, you have all the quinoa you can use.
So if we ever have to rebuild the seed supply for growing crops, we should focus our initial efforts on amaranth and quinoa. Of course, we need a wide variety of foods for a healthy diet. So at the same time, we have to apply some resources to rebuild the seed supply for wheat, corn, rice, barley, and many other crops. But for survival purposes, in order to produce as much food as possible in the shortest amount of time, amaranth and quinoa are the king and queen of survival crops.