What are the advantages of using urea versus nitrate nitrogen?
Passchier: From industry watercooler conversations, I hear people saying a nitrate-based fertilizer grows a more compact plant and achieves very nice leaf expansion when using some controlled-release urea in the formula. There are places for ammonium nitrate, nitrate nitrogen and urea-based CRF fertilizers. In many instances, it comes down to an individual grower’s personal preference based on past experiences and cost. Pilon: In a greenhouse, is ammonium toxicity a concern? Passchier: The word toxicity means there is a concern, but when you manage your crop to grow in a healthy environment, the chances of ammonia toxicity is minimal. If there is a healthy growing environment with a healthy micro-organism population for converting nitrogen, the likelihood of ammonium toxicity is greatly minimized. Poorly drained, heavily watered, anaerobic soils are not good environments for growing plants. Avoid these conditions and ammonium toxicity is usually not an issue.