On the one hand, because the soluble fertilizer is directly applied to the densely rooted area of the crop with the water, there is no waste of fertilizer on the open space between the crops.
On the other hand, drip irrigation in the drip line irrigation system penetrates into the root zone in the form of a small flow of drips, which is very easy to control. Neither water nor fertilizer will be wasted by deep washing. Nitrogen application in drip irrigation system can achieve 74% fertilizer efficiency, while traditional application method does not exceed 30%.
Nitrogen fertilizer is the most applied fertilizer by drip irrigation system. Nitrogen fertilizers generally have good water solubility and are very easy to be applied to the root zone of crops as water drips into the soil. However, if it is not properly controlled, it is easy to cause leaching loss.
Due to the small drip irrigation flow (single drip head: 4~8 liters/hour), it is very easy to control the leaching damage. If irrigation and fertilization are automatically controlled, leaching damage can be completely avoided.
Among all nitrogen fertilizers, urea and ammonium nitrate are the most suitable for drip irrigation. Because the application of these two fertilizers has the least risk of clogging, the application of ammonia in drip irrigation systems is generally not recommended, because ammonia will increase the pH of the water. An increase in pH will cause calcium, magnesium, and phosphorus to precipitate in the irrigation water, clogging the dripper. Ammonium sulfate and calcium nitrate are water-soluble, but there is a risk of clogging.
If nitrogen is applied continuously. After the drip irrigation system stops pumping. There will still be nitrogen in the water in the drip irrigation system for a long time. At this time, the presence of nitrogen will nourish the growth of microorganisms in the system, and finally block the dripper.