Despite strong advocacy of smart organic farming practices, it must be recognized that industrial farming is not going away immediately. Given that, we should at least make fertilizer-based farming as environmentally-friendly as possible. The "N-Checker" (N for nitrogen) system, therefore, looks to be a step in the right direction.
Rapid pulses of polarized light can reveal nitrogen content in the leaves of crops, indicating how much fertilizer to apply, reducing the amount of waste. Less overuse of fertilizer, in turn, would "dramatically cut the nitrogen-laden runoff responsible for algal blooms and other damage to wetlands and waterways." The system can analyze around one plant per second, making it possible to cover tens of acres in a day.