Precision farming—adjusting nitrogen fertilizer applications to fit the precise needs of crops—sounds like a good solution. Is it enough to fix the pollution problem?
Synthetic nitrogen fertilizer is often applied just once during the year, supplying a large amount of nitrogen that cannot be entirely assimilated by crop roots before much escapes to the wider environment. Precision farming aims to apply fertilizer in amounts that are adequate to attain desired yield without exceeding the amount that the crop can utilize. Spring application usually results in less loss than fall application, and some farmers split fertilizer applications between the beginning of the growing season and later in the year. But these simple practices are inadequate to fine-tune fertilizer application to the specific nitrogen needs of each crop. To be more precise requires technology such as GPS systems and remote crop sensors that may be out of reach of many farmers. And even with the use of precision agriculture methods, weather and other unpredictable events that occur after fertilizer applications may slow crop growth unexpectedly, leading to substantial nitrogen loss.
