With recent projections of crop and input prices, the profit margins are looking to be tight again in 2016. Soil testing may be a beneficial tool to help target your nutrient applications and get the best return for your investment.
At our final workshop of 2015 last night near Iowa City, nutrient management was the topic of discussion. The workshop was held in partnership with the Rapid Creek Watershed Project, Johnson County Soil and Water Conservation District and Iowa State University Extension and Outreach (ISUEO).
Meaghan Anderson, ISUEO field agronomist explained the importance of soil sampling techniques and understanding the field’s management history when interpreting soil sampling results for phosphorus and potassium. She showed an example of a field that from an aerial photo looked to be fairly even, but the phosphorus soil sample results showed a very different picture. Looking back through aerial photographs, she tracked the field back to the 1950s to see that the now one field had been broken into many smaller fields and managed differently over the decades resulting in wide differences in soil nutrient values.
Now that the history and results are paired, a more economic nutrient plan can be developed to apply the phosphorus in the areas where it will generate a return through improved soil productivity. The same can be done for nitrogen and other soil nutrients.
For more information about soil sampling techniques and interpreting soil samples results, check out this ISUEO 2-page publication “The Dollars and Sense of Soil Sampling”.