Nitrogen Fertilizer for Lawns

Types

• When animals or plants die and begin to decay, it results in organic nitrogen being absorbed into the soil. The creation of this organic nitrogen is a benefit of compost piles. When the compost is mixed into the soil, the nitrogen is transferred to the soil as well. The drawback of organic nitrogen is that it can take a long time to be broken down in the soil and be used by the plants.

  An alternate to organic forms of nitrogen are inorganic forms such as nitrates or ammonium that can be used by plants more quickly. However, inorganic forms of nitrogen can also be moved away from the desired area of fertilization by underground water movement.

Danger of Too Little Nitrogen

• Nitrogen is an important requirement for plant growth. Serious damage can occur if a plant can't get enough nitrogen. The University of Minnesota states, "Too little available nitrogen leads to slow growth, increased chance of some diseases, yellowing of plants and thin turf, resulting in increased weed pressure."

  To ensure that a plant benefits from nitrogen fertilizer, it is important to apply the fertilizer when the plant is the most active. The best time of the year to apply a nitrogen-based fertilizer is during the warm months of the growing season when plants are productive. But fertilizer should be applied only as often as specific types of grass and growing conditions require.

Danger of Too Much Nitrogen

• Too much nitrogen fertilizer in your soil can be a bad thing as well. Over-applied nitrogen will not remain in the soil until it is used. Instead, it will seep into the groundwater and be moved away from the plants it was meant to fertilize.

  Excess nitrogen will also cause a plant to grow too many leaves and shoots and not enough roots. This can affect your grass in a similar manner.

Common Nitrogen Fertilizers

• Rapid-release nitrogen fertilizers are often used on turf grass and result in a brightening of color and grass growth. Quick-release fertilizers are made up of ammonium nitrate, ammonium sulfate and urea. The benefit of the rapid-release fertilizer goes beyond fast response from the plants. They are also significantly less expensive.

  Slow-release fertilizers breakdown more slowly in the soil and only small portions become available to the plants at a time. This type of nitrogen fertilizer depends greatly on the type of soil conditions that the nitrogen is applied to. The soil may make the breakdown and absorption of the nitrogen even slower. The benefits of slow-release fertilizer are that it can be applied more often and will last longer. It is also a good choice for grasses in sandy soil.

Considerations

• Since too much nitrogen can damage plants, it is important to maintain a healthy balance in the soil. The easiest way to accomplish this is to apply an inorganic fertilizer that is mixed with phosphorus and potassium. A fertilizer that is mixed 10-10-10 will contain equal parts of phosphorus, potassium and nitrogen. This allows the lawn to receive all the natural nutrients needed and keeps the nitrogen level balanced. If a mixed fertilizer is not used, it will be necessary to conduct pH balance checks of the soil occasionally to ensure that the nitrogen level isn't becoming too great.