I read a great piece in agprofessional.com titled “Nutrient management related to dry soil conditions" and wanted to share it. A few key points I'm quoting from the piece:
- Unfortunately if dry soil conditions continue, soil samples taken this fall (if the ground is soft enough to get a sample) may provide misleading results for K. Soil test K has been shown to vary substantially with dry conditions.
- Soil pH measurements are also affected by dry soil conditions. With a dry season and poor plant growth much of the fertilizer added this spring and last fall remains in the 8-inch sampling zone. Higher than normal salt (fertilizer) levels affect the way the pH electrode functions and will produce a pH reading about 0.5-1.0 pH units lower than the actual pH. In addition, soil moisture has been insufficient for normal amounts of limestone reaction in soils limed this spring or last fall. Therefore, soil pH measured this fall will be lower than expected. The lime remains in the soil, however, and when moisture returns it will increase soil pH as expected. Re-testing this fall and adding more lime based on a low soil pH measurement may result in excessively high pH in future years.
My response: while lime needs moisture to react, the reaction speed of limestone is based on lime source and particle size more than anything. Finely ground calcitic limestone will react much faster than coarse ground calcitic, and much faster than dolomitic, even when ground ultrafine. Finely ground lime like SuperCal 98G should be left on the surface and worked in by moisture only; do not work it in, especially in a dry year. This will make sure proper dissolution of the lime.
Yield Starts Here is a blog for farmers, focusing on increasing yield and profitability by focusing on the soil. It is managed by Craig Dick, the blogronomist and VP of sales and marketing at Calcium Products. Find other articles by Craig and guest writers at blog.calciumproducts.com.