soluble fertilizers 20-20-20- for landscaping and their rate of use for 1000 square meters?

the use will be in irrigation system in the middle east area

Answers:
If you're using a drip irrigation system, which I recommend, then you want about 200 parts per million of soluble nitrogen in the water. Even though fertilizer manufacters say to fertilize every time you irrigate, you will more than likely just waste fertilizer this way. You can fertilize once or twice a week and get the same results. You will want to use one gram per liter of water to have 200ppm concentration (one gram of 20-20-20 fertilizer = 200 milligrams of N).

There are a lot of assumptions here to be careful of. One is that that the soil is not abnormally well drained, and has enough CEC to hold the nutrients until the plant can absorb it. The other is that the plants are not adapted to either abnormally high or abnormally low nitrogen concentrations. Many desert plants thrive in a fairly nutrient poor environment. Also getting the irrigation rate right is more important than getting the fertilization rate right. In the middle east lack of water is going to kill the plants quicker.

Use a powder formulation instead of a liquid formulation. It will be easier to figure out how much fertilizer to add.

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