Fall Limestone Application: Makes Sense, Saves Dollars!

The best time to apply limestone to your fields is in the fall. There are two main reasons for this. First, from an agronomic point of view it makes the most sense. 

What happens when limestone is applied to soil? In our Fraser Valley soils there is an abundance of aluminum, which naturally reacts with water to produce hydrogen ions (H+). The presence of a concentration of H+ creates acidity. When limestone (calcium carbonate) is added to the soil, some of the calcium replaces aluminum at the cation exchange sites. Meanwhile, some of the carbonate combines with hydrogen to produce water and carbon dioxide. This reaction is not instant, especially if the limestone is not incorporated. Typically, several months pass before the biggest change in pH takes place. 

If limestone is applied in the fall the pH should be increased just in time for fertilizing time in the spring. The second reason for applying limestone in the fall is time. The fall is typically drier than spring so fields are better able to handle the weight of spreading equipment without damaging the soil. Application can be timed right after the last cut of grass or directly following corn harvest. Also, bad weather in the spring with wet soils often means we can’t get to all the orders in time prior to planting. Inevitably, some are cancelled and yield and quality are compromised. It makes far more sense to do some of the spreading in the fall when we can quickly drive across dry fields.