News > Agronomy Blog > Agronomy Blog > September 2020 > Nutrient availability in low pH soils

Nutrient availability in low pH soils

September 21, 2020

Combines are just getting started and this is the time of year to think about liming your soils. Ground in our trade area is subject to lower pH because of the use of nitrogen fertilizer and the parent material. It is important to know what the soil pH is in order to maximize crop nutrient availability. As the soil pH reduces, the availability of macronutrients like nitrogen, potassium and phosphorus is reduced. Once a soil starts to dip below 6 pH nutrients, especially phosphorus, become more unavailable.

Below is a diagram that will show the availability of nutrients based on soil pH. As you can see phosphorus drops off very quickly once soil becomes more acid. The ideal pH range for corn and soybeans is 6.5 because that is the point where nutrients are most available. We fix this problem by liming soil or using products that make phosphorus more available. Avail T5 is a product that can increases available phosphorus from 30% to 70% of applied P. Avail achieves this by using polymer technology that will bind the nutrients that ties up phosphorus in the soil. For example, Zinc ties up phosphorus and makes a compound that is unavailable. Avail T5 will tie up the zinc and allow phosphorus to be used in the plant. We see very good results from Avail in areas of low pH or low soil fertility. Using these type of nutrient availability products allows us to avoid relying solely on our soil banks and maximizing our fertilizer applications. Ask us at SFG about nutrient availability and maximizing soil pH on your farm.