The Best Soybeans to Plant in Alkaline Soils

Soybean pH

• Soybeans are highly adaptable to a wide range of soil profiles and will grow in any soil that is not either too alkaline or too acid. According to the University of Nebraska-Lincoln website, growing soybeans in alkaline soils causes unsightly chlorosis, or leaf yellowing, particularly in soils with a pH value of 7.5 or higher. Soil alkalinity can also cause iron, zinc, manganese and molybdenum deficiencies, which can lead to diminished new growth and poor bean yields.

Adjusting Alkaline Soils

• What to do when trying to grow soybeans in alkaline soils depends in large part on how alkaline the soil is. If the soil is only slight alkaline (7.0 to 7.5 pH), you may be able to make the soil more acidic through the addition of ammonium sulfate or a similar fertilizer that lowers pH values. Test your soil pH again to determine whether incorporating the fertilizer adjusted your soil into the ideal pH range of 5.8 to 7.0. If the soil is still too alkaline, some extra measures need to be taken to properly grow soy in this soil.

Variety Selection

• Some varieties of soy adapt better to alkaline soils than others. Dekalb-pfizer,

  golden harvest, jacques, McCubbin and NC+ varieties of soy have shown a high resistance to chlorosis onset from highly alkaline soils, so if your soil pH is 7.5 or higher, seek one of these varieties for planting in your garden. Asgrow, fontanelle, hoegemeyer, horizon and northrup king varieties are also resistant to chlorosis from alkaline soil, though not as tolerant as the aforementioned varieties. Therefore, these latter varieties would be a better choice for slightly alkaline soils that are outside of the ideal pH range -- perhaps between 7.0 to 7.5.

Other Tips

• In its extensive guide to cultivating soybeans in alkaline soils, the University of Nebraska-Lincoln also recommends several cultural practices that will enhance your chance of success when growing soybeans in alkaline soils. These suggested practices include planting soybean seeds at a rate of 12 per foot of row, because chlorosis is more severe when plant density is low. It also recommends adding iron chelate with seeds and spraying soybean foliage with an iron sulfate solution. By adhering to these guidelines, you can grow healthy and long-lasting soybeans even in alkaline soils.