Markets typically do not like uncertainty and commodity markets are no exception.
The chart below depicts the effect on grain prices during times of uncertainty in world events over the past seventeen years.
Grain prices normally rise during these times due to various reasons including reduced production or trade interruptions as seen recently from the Ukrainian war. Keep in mind that one additional major change happened around 2007 which was the beginning of the huge growth in ethanol production which created competition for planted acres.
If you plot the trajectory of land values during this time, we would see the upward trend starting to accelerate in the 2005 to 2007 time frame continuing through 2013-14 with a several-year decline and plateauing till 2020.
A slight upward trend resumed in 2020 and early 2021 after which land prices experienced a sharp increase in the last part of 2021 and the first months of 2022. Of course, there were other major factors boosting land values over time including the more recent span of low-interest rates and low supply of good farmland for sale, but world events that boost commodity prices and therefore farm income do have an effect on land values.