Low pH and subsequent Magnesium Deficiency and Aluminum Toxicity

scouted June 12, 2023

Soybeans were scouted at the V5-6 growth stage and widespread yellow discoloration and poor nodulation was observed.
This issue was confirmed by an NC State Extension Specialist as a Magnesium (Mg) Deficiency and Aluminum (Al) Toxicity caused by low soil pH. Magnesium deficiency is often associated with low soil pH, and the major symptomology includes interveinal chlorosis of lower leaves. Symptoms associated with Aluminum toxicity are severely stunted plant growth, deformed root tips, overall lack of root development, and poor nodulation. In this environment, it was suggested to incorporate dolomitic lime with a fine particle size for a faster reaction.