Molybdenum

Nobody soil tests for molybdenum, and in the Southeast you don't need to. Your pH number is doing that job. We dig into how Mo behaves in our soils, when soybeans actually respond, and whether there's anything to the idea that Mo can protect wheat falling number. pH is your Mo test — Molybdenum works backwards from most micronutrients. Acid soil locks it onto iron and aluminum oxides, and lime releases it. No Southeast lab offers a calibrated Mo soil test. Clay vs. sand — Piedmont red clays hold a Mo reserve that liming frees up. Coastal Plain sands have less to release, and pushing pH above about 6.2 there invites manganese deficiency. Why soybeans care — Nodule bacteria need Mo to fix nitrogen, so a Mo-short soybean looks N-deficient with poor nodulation. When seed treatment pays — On fields limed to target pH, expect no response. On acid, un-limed ground below about 5.8, a low-cost Mo seed treatment is cheap insurance, though it's no substitute for lime. The falling number question — Mo helps the plant make ABA, the hormone behind seed dormancy, and Mo-starved wheat sprouts more easily in lab studies. But no study has ever measured Mo's effect on falling number, and none has tested soft red winter wheat. What actually protects falling number — Variety choice and prompt harvest. Don't spend money on foliar Mo for wheat quality.