How to grow soybeans
- Second most planted crop in the U.S.
- Plants fix nitrogen, so they are often planted in rotation with corn
- 427.15 Million metric tons harvested worldwide last year
- Processed for enviro-friendly oil, livestock feed, biodiesel and many other uses
- Only 6% is consumed by humans, mainly as cooking oil
Growing soybeans
- Soybeans are planted from purchased GMO-modified hybrid seed
- Over 10,000 cultivars are available for better yields & herbicide/pest resistance
- In the Midwest plant as soon as soil temps reach 50F, ideally in April
- Typical effective root zone is 24”
- In some parts of the country soybeans have been planted successfully for 20+years without rotation
- Growing season for soybeans depends on the cultivar, typically between 90-150 days
- Growers harvest when the seed pods are not quite brown, or they may turn brittle and shatter on harvest, reducing yield
- Expeller pressing can extract 12-14% of soybeans as oil. Solvent extraction of the cake can bring total yield up to 18-20%
The market for soybeans
Since year 2000 the global soybean supply has more than doubled from 200 million tonnes to over 500 million tonnes, a 4-5% growth rate over the period. Demand has grown at 3-5%, although since 2015 demand has not kept up with supply. Brazil is the top world producer of soybeans at 171.5 Million tonnes for 2024/2025, followed by United States at 119.05 Million tonnes and Argentina at 51.11 Million tonnes. While China produced over 20 million tonnes, China is the world’s largest importer of soybeans. Between January and October of 2025, Brazil exported a record 79 million tonnes of soybeans to China, nearly 80% of its total soybean exports during the period. In November of 2025, the U.S. and China concluded a trade deal for soybeans, with China agreeing to buy 12 million tonnes in November-December 2025, and at least 25 million metric tons annually through 2028.
In the U.S. soybean futures were 25-30% lower in November 2025 than at the same point in 2022. Growers were also beset with higher input costs on fertilizer, pesticides, seeds etc., leading to a third year of losses for growers. Some growers shifted production to corn, which in 2025 experienced a record production year, leading to highly depressed prices.
Agricultural challenges with growing soybeans
Overwatering soybeans can lead to tall leafy plant susceptible to disease and lodging, where the plant stem bends at the soil level. Straight corn-soybean rotation can lead to deterioration of nutrients, as microbes in the soil used to soybeans eat older nutrients when corn is planted. Soybeans do not grow quickly after emergence, and can be out-competed by herbicide-resistant waterhemp and other weeds. Waterhemp infestation can cause crop yield losses of over 40%. Soybeans can mature rapidly as the fall days get shorter, so the timing between final watering and harvest is critical.
Nitrogen Use Efficiency for Soybeans
Soybeans are legumes that have a symbiotic relationship with arbuscular mycorrhizal fungi (AMF), forming root arbuscules where the AMF can fix nitrogen. Because soybeans have a high protein content, the production of which uses a lot of nitrogen, the contribution of AMF by itself can be insufficient for good yields.
How can the nitrogen use efficiency be improved?
- Nitrogen application timing is critical, as excess N can limit yield
- Avoid tillage as it can disrupt mycorrhizal hyphal networks.
- Early application of fertilizers can make soybeans “lazy”, so that they do not form nodules (arbuscules) for hosting nitrogen fixing bacteria.
Contact AquaSpy
AquaSpy for Soybeans
With a Crophesy LS-N annual subscription, you receive a free simple, three-sensor or six-sensor, wireless, soil moisture probe. Place these rugged, water-tight probes throughout your soybean field and connect them easily to the Cloud for hands-free data uploads throughout the day.
Then you can instantly monitor soil and crop health for all of your soybeans. And if you want to test the soil in other areas, you can quickly and easily move the moisture probe, which is battery-powered and provides season-long insight.
While you can look at the visual analysis of leaves, spending hours in your field, Crophesy enables you to open your app from anywhere and show you what kind of nourishment is available in your soil at your soybean crop root depth. With this data, you can determine when the active root zone needs vital nutrients.
In addition to nitrate (NO3-N ppm) data, the Crophesy LS-N app can show you:
- Nitrification and Denitrification (ORP mv)
- Moisture consumption at the root level
- Salinity level in the active root zone
- Root depth
- Soil temperature near the sensors
- Irrigation depth
And it tells you all this without you having to step foot in your soybean field.
