Rahul Somvanshi
A Wisconsin farmer’s video argues that synthetic nitrogen is mostly lost from cornfields while “organic nitrogen” stays in soil until plants need it. The underlying concern—nitrogen losses can pollute water and warm the climate—is valid. But the chemistry in the video is too simple to serve as a fertilizer guide.
Corn does not use every kilogram of applied nitrogen. Fertilizer-use efficiency depends on weather, soil texture, timing, placement, crop demand and management. Nitrogen can leave fields through nitrate leaching, runoff, ammonia loss to the air and microbial processes that produce nitrous oxide. A 40% recovery figure can occur in some situations, but it is not a fixed rule for every Wisconsin field or every fertilizer programme.
Organic and synthetic nitrogen are not opposites in the soil
Compost, manure, crop residues and cover crops contain organic nitrogen. Much of that nitrogen is initially bound in organic matter and must be converted by soil microbes into plant-available forms. That conversion is called mineralisation.
Once organic nitrogen becomes ammonium and then nitrate, it can be lost in many of the same ways as nitrogen from synthetic fertilizer. Nitrate is water-soluble regardless of whether it originally came from compost, manure, cover-crop residue or a bag of fertilizer. Organic sources can improve soil structure and release nutrients over time, but they do not guarantee that nitrogen will remain in place until a crop “calls for it.”
Is synthetic nitrogen always worse than organic nitrogen? No. Both sources need careful management. Excess nitrogen from either source can threaten water quality and contribute to air pollution. The practical goal is to match the source, rate, timing and placement to crop demand.
Can farms reduce nitrogen losses? Yes. Split applications, soil testing, realistic yield goals, cover crops, buffers and avoiding application before heavy rain can all help. The U.S. Department of Agriculture describes nutrient management as a way to protect water while maintaining crop productivity.
The video is right that building soil organic matter can support resilient farming. It is not right to say that the oceans can no longer absorb carbon, or that a carbon bond makes all organic nitrogen permanently non-water-soluble. Soils, oceans and vegetation continue to exchange carbon, although their capacity and consequences are central climate concerns.
The useful takeaway is not to replace one slogan with another. It is to reduce avoidable nitrogen losses through measured, field-specific management—whether a farm uses synthetic fertilizer, compost, manure or a combination.
