Researchers are studying the improvement of acidic soils with beet lime at the University of North Dakota, USA.

The Northern Central Research Center (NCREC) of the State University of North Dakota, USA, has been studying the improvement of acidic soils using beet lime for many years, starting in 2019 and continuing into the 2020s, according to AgroXXI.ru.

The pH level of acidic soils is less than 7, while alkaline soils have a pH exceeding 7.

Troubles with soil acidity arise only when the pH level reaches 5.5 or below. However, according to Chris Augustin, a soil health expert from NDSU Extension, if the pH drops below 6, then using lime makes sense. Moreover, beet lime, obtained from sugar beet processing, costs about three times less than imported lime required for the state of North Dakota.

According to Augustin, in North Dakota, soil acidity is caused by the constant application of nitrogen fertilizers.

High acidity is observed in untreated soils in the central and western parts of the state, mainly in the upper soil layer at a depth of 3-5 cm, especially in fields where year after year the urine surface application method of urea has been used.

"Since nitrogen is the cause of acidity, we find that it is precisely where this nitrogen is used year after year that the most pronounced acidic spot is observed," the expert says.

Acidic soil can lead to phosphorus deficiency in plants and slow root growth. In extreme cases, the number of seedlings may be very low.

To conduct an experiment on beet lime application, NCREC purchased beet lime from Sidney Sugars company in the state of Montana, which delivered it at a price of $41 per ton.

Regular lime costs between $120 and $130 per ton. The calcium carbonate content in beet lime is approximately 20% higher than in regular lime. Therefore, to achieve the same calcium content, it is necessary to use beet lime by 20% more, but even this increase will not raise the cost.

In the first year of the experiment, the soils had a pH level of 5.3 at a depth of 0 to 5 cm. After applying 2 tons of beet lime per acre, the pH level increased to 6.5. With the application of 4 tons of beet lime, the pH reached 6.7. The lime was surface-applied in the spring. Soil analysis was conducted before lime application in May and early October.

This year, researchers continued lime application with beets to develop recommendations on lime application rates and methods.

Likely, beet lime may not need to be applied every year. The frequency of application can be once every 5, 10, or even 20 years, depending on the specific pH level in the fields. Moreover, there is no need to cover the entire field area. Acidic zones can be identified and treated using precision farming technologies.