Nitrogen is vital to your lawn and is one of the most popular fertilizers. You need nitrogen because chlorophyll depends on it as do other proteins and amino acids. These in turn are what makes your lawn green and causes it to grow well.
Some things to look for to see if your grass has a nitrogen deficiency are; if it turns yellow despite watering, the grass doesn't grow quickly, diseases are present in your lawn, or if the grass turf starts getting thinner.
Depending on the time of year, your budget, and the climate there are three basic types of nitrogen used in fertilizers that are popular to apply.
1. You will find isobutyledenedinurea (IBDU) which decomposes slowly and will feed your grass over a longer period of time. It will often take a couple of weeks to decompose enough for you to see it's effects on your lawn.
This is the most expensive form of nitrogen fertilizer because of the way it is manufactures and it's uniformity. It's uniformity also makes it very easy to apply.
2. There is also sulfur-coated urea. It depends on how thick the sulfur coating is to determine how quickly it will dissolve and feed your plants.
S.C.U. will release quicker when the temperature is hotter, the lawn is wetter, or if the grass is healthier.
3. The last one I am going to mention is urea, a fairly inexpensive nitrogen. It is the cheapest nitrogen to produce as well as the fastest acting.
You can often see results over night, it is that fast. But it gets depleted quickly and if you over apply it you can easily burn your yard up and kill your grass.
So the next time you go shopping for fertilizers with nitrogen check the labels and ask lots of questions.