The common production technologies of compound fertilizer include tower, ammonification, shotcrete and roller. The advantages and disadvantages of these technologies are briefly introduced as follows:

1. Roller granulation process is simple, but smooth granulation, but the water dissolution rate and utilization rate is low, easy to lose, but in drought years for crops with short growth period topdressing effect, is better than the drum spray granulation fertilizer effect faster.

2. The grain size of rotary drum spray granulation is hard, and the fertilizer effect is longer than that of high tower granulation, so it is unfavorable to be lost, and easy to be used as base fertilizer for crops in the long growing period.

3. Ammoniated granulation is pipe spraying granulation, fertilizer effect period between the drum and drum spraying, using law is better than spraying, and lower than high tower granulation, water solubility is good, particles into irregular shape, high nitrogen and high potassium content can be freely adjusted, suitable for formula fertilization.

4. High tower granulation particles smooth, hollow anti-counterfeiting, balanced content, NPK is more free to mix, fertilizer effect in compound fertilizer fast, easy to dissolve, suitable for topdressing. Disadvantage is in granulation spray, urine melt, if the process time flow control is not good, easy to produce a large number of biuret, there is also the production of water is easy to exceed the standard.