Published on Tuesday, January 17, 2017
A few months ago, we took a time out of summer crop scouting to think about why the heck we grow corn. Now is the time to look at that other crop: soybeans. Soybeans are the small, but mighty little brother.
Nitrogen (N) is one of the most limiting nutrients for plants. Without N, plants can’t build proteins into new cells. Every day, you and I swim around in an atmosphere that is 70 percent N. We breathe it in, exhale, and it leaves our bodies unchanged. Nitrogen in the atmosphere is pretty much inert – a fancy scientific term which means really, really stable and therefore really, really hard to use. Think about having a 25 lb. block of rock salt on your counter. You probably wouldn’t put salt in every recipe if you had to use a chisel to hack off a piece, and then a mortar and pestle to break it down in granular form. You’d just live an unsalted life. Plants (and people) don’t have the option of just not using N – it’s essential for every single cell in every single living thing! In the air we breathe, two N atoms float around connected by triple bonds. Triple bonds mean it takes a molecular powerhouse to bust them apart and put them together in a more accessible format.
The pink color inside the soybean nodule is a good indicator that the bacteria are hard at work blasting open molecules of nitrogen gas and feeding that nitrogen to the plant. (Source)
Soybeans have a superpower. They share this superpower with about 19,000 other members of the Fabaceae family. When I taught college agronomy, I told students to remember the fabulous N-fixing Fabaceae.
For millennia, humans have gotten the N required to build our bodies from our food: protein-dense foods like meats and beans in particular. Have you ever stopped to think why beans are on that short list? Why are they so high in protein? It’s because they are members of the fabulous N-fixing Fabaceae. They form an alliance with naturally occurring bacteria in the soil. The bacteria blast open the N gas from the air and then use them as building blocks to make plant food. The bean plant gets food and the bacteria gets a nice safe place to live and carbon from the plant for their trouble. The fact that plants can suck carbon right out of the air is worth another blog post in itself! The plants pack all of that N, now in the form of proteins, into a neat little round seed. The soybean. We can either eat that soybean to get the N, store the soybean and eat that N later, or feed it to a livestock animal and get our N from meat.
China has been in the soybean production game for well over 2,000 years. U.S. production started out with the robust, drought-hardy plants being employed as a pasture crop for grazing, and sometimes the whole plants were co-ensiled with corn for winter feed. The Mid-Atlantic states were first to embrace soybeans as a part of the diverse American farmscape. Widespread commercial production ramped up in response to a wartime demand for domestic sources of protein, fats and oils during World War I. By 1937, the same year that Beck's was founded, soybeans were being traded on the Chicago Board of Trade.
Today, a record 83.7 million acres of our continent have been planted with soybeans. The ‘little brother’ is no longer just a rotation crop and it’s almost never grazed by livestock. Soybeans are about 18 percent oil and 38 percent protein. The vast majority of soybeans are crushed, treated with hexane to remove the oil, then the remaining ‘cake’ is used as high-protein animal feed. The balance of the crop is used in everything from animal feed, cooking oil, biodiesel, lubricants, particle board, candles, tofu, cosmetics – you name it, a soybean can probably be used to make it!
Author: Samantha Miller
Categories: Ag Education
Tags: soybeans, Ag Education, Ag Chat, nitrogen intake, triple bonds, Fabaceae, plant protein soybean production
Clarence A Mason
1/27/2017 9:18 AM
I kinda knew that soybeans did something to the soil to replace N, but now thanks you and your blog post....I understand.....Thanks again.
1/31/2017 7:18 AM
I will be coming to the US sometime in March this Year, I would like to visit Becks Farm. Thank You