Optimizing Nitrogen Fertilizer Applications
Corn crop prices are low and fertilizer prices are high. Farmers are looking for ways to lower their nitrogen (N) fertilizer bill. University N recommendations have changed over the years. University N research in the 1950’s advocated heavy N fertilizer because yield increased as N application increased?? Extra N fertilizer was a cheap fertilizer insurance policy. About 10–15 years ago, universities re-examined that original data and found little direct relationship between higher corn yields and higher N rates. The relationship was quite variable! Five major factors like temperature, moisture (weather), soil pH, soil oxygen levels, and soil organic matter (SOM) affects plant N uptake. The N relationship to yield is so variable that universities went to a N application rate based on the price of N relative to crop prices. As N prices increase and crop prices decrease, economically it’s better to cut back while if N is cheap and corn prices high, the N rate is increased to increas...