What are the methods for identifying controlled-release fertilizers?
What methods are used to identify controlled-release fertilizers? Please explain the identification methods. To identify genuine versus fake controlled-release fertilizer, you can refer to the following methods: The rub test: genuine fertilizer is not afraid of rubbing; its coating has good strength and high strength, and when you rub the granules with both hands, the coating does not lose color or come off; fake fertilizer is afraid of rubbing. Poor-quality or fake controlled-release fertilizer, because its strength does not reach...
What methods are used to identify controlled-release fertilizers? Please explain the identification methods.To identify genuine versus fake controlled-release fertilizer, you can refer to the following methods:
The rub test: genuine fertilizer is not afraid of rubbing. Its coating has good strength and high strength, and when you rub the granules with both hands, the coating does not lose color or come off; fake fertilizer is afraid of rubbing. Poor-quality or fake controlled-release fertilizer, because its strength cannot meet the requirements for controlled release, loses color when rubbed with both hands, and the coating comes off easily.
The knife test: genuine fertilizer is not afraid of being cut. Its coating wraps the fertilizer very firmly, and after cutting with a knife, you can clearly see that the coating thickness is very uniform and the boundary between the coating and the fertilizer is clear, just like an eggshell; fake fertilizer is afraid of being cut. After ordinary inferior or fake controlled-release fertilizer is cut open with a knife, the coating thickness is uneven and non-uniform, and the coating production process cannot meet the requirements for controlled-release fertilizer.
The count test: genuine fertilizer is not afraid of being counted. The proportion of coated granules reaches more than 20%, and the total nitrogen content is greater than 8%, with a total nitrogen release rate of no more than 80% over 28 days, effectively ensuring the controlled-release effect; fake fertilizer is afraid of being counted. To reduce production costs, inferior controlled-release fertilizer has a granule proportion below 15%, so it cannot meet national standard requirements and cannot achieve the controlled-release effect.
The soaking test: genuine fertilizer is not afraid of soaking. When soaked in clean water, genuine controlled-release fertilizer granules do not dissolve within a short time, and the water remains clear with no impurities, while bubbles emerge around the granules. After soaking for a long time, you need to use a sharp object and apply force to peel off the outer coating.
It is precisely because of the slow release effect, which is consistent with the fertilizer demand pattern of crop growth, that there is no excessive vegetative growth in the early stage and no fertilizer shortage in the later stage, giving a very good controlled-release effect; fake fertilizer is afraid of soaking. When ordinary or inferior controlled-release fertilizer is placed in clean water, the granules dissolve within a short time, the water becomes turbid, and impurities settle in the water, and after soaking, the coating comes off easily. Because of the extremely strong dissolution and release or the coating coming off, when fertilizing crops, it easily burns the seedlings in the early stage and easily causes fertilizer shortage in the later growth stage, so it cannot achieve the controlled-release effect.
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