January 2026
By Hans Schmitz, Technical Assistance Specialist, Indiana Ag Nutrient Alliance
There’s an old saying that wheat greens up after a good snow. The saying derives from the theory that there’s enough nitrogen in snow to recharge a little growth. Snow does contain some nitrogen, in both plant available forms of nitrate and ammonium. The nitrate is derived from nitrous oxides emitted in burning of fossil fuels, while the ammonium is mostly a result of fertilizer volatilization and natural microbial processes. The deposition rate is variable, with us in the east receiving about double the amount that those in the western US can expect. In an analysis of articles on the topic, the range of benefit is reported between 0.3-0.8 lbs/acre/inch of snow. The lower amounts are measured in places like South Dakota, while higher amounts would be recorded in Indiana, generally 0.7 lbs/acre/inch.
In this case, a foot of snowfall will contribute 8-10 pounds of plant available nitrogen to any living cover or cash crops in the landscape. Snow nitrogen over bare soil likely loses this benefit to soil microbes or runoff over the winter. This nitrogen source should not be counted towards any planned rates of applied nitrogen in the case of winter wheat, and nitrogen fertilizers should never be applied to snow-covered ground. A study from South Dakota State University found negative effects on winter wheat yields when urea was applied to snow-covered ground as compared to urea applied to bare soil.
The green up factor cannot be fully contributed to nitrogen deposition during snow melt. The cool season plants that survive our winters have photosynthetic capability anytime the temperature is above freezing, and temperatures generally have to be above freezing to melt snow. The greening observed is likely a mix of a little N boost and the warmer temperatures observed leading to a restart of photosynthesis in the plant.