SOIL PRODUCTIVITY INDEX

One of the key factors in determining the value of Illinois farmland is based upon the productivity of the soil. On the Sterling Land Company website, properties for sale will usually be accompanied by a soil productivity index rating. While it’s sufficient to say the higher the number, the better the soil, gaining an understanding of the basis behind these ratings can help justify land prices.

The soil productivity index ratings for Illinois farmland run from a low of 100 to a high of 147. Lands with soil productivity index ratings below 100 are not considered to be prime farm ground.

Often times, a farm will be described as an A, B or C class farm. This determination is based on the soil productivity index number. Class A soils will have soil productivity index numbers between 133-147. Class B soils will have soil productivity index numbers between 117-132. Soil ratings below 116 are considered class C soils.

Soil productivity index numbers are based upon the productivity of the soil. They are derived from the mean annual yield that these soil types produce over a 10 year period with moderately managed crops.

The University of Illinois at Champaign-Urbana published an update to their 1975 soil productivity index ratings in 2000. Although the actual yields have improved since the time of publication, the disparities between the differing types of soils have changed little. Therefore, it is still an effective method to gauge the value of the land using the soil productivity index numbers.

Understanding the soil productivity index is a helpful tool in determining land value. However, there is still a significant price disparity between lands that carry the same soil designation. Class A soils are the best, but they still vary greatly in price based on many factors.

Sterling Land Company agents can help you gain a better understanding of the land market. On our website, you can sign up for our free land report. Included in the report is a breakdown of recent land sales with their soil productivity index numbers.