Direct Ag Supply Inc. Share: Equipment & Supplies - Ag Direct Ag Supply Inc. Visit Website 2120 40th Ave. SE Mandan, ND 58554 (701) 751-5077 About Map About An agriculture seed, chemical, fertilizer and equipment dealership. We are an authorized dealer of DeKalb/Asgrow and NuTech, along with a complete line of chemical and fertilizer. What's Nearby? Distance: 5 10 15 20 25 50 mi.