Calcium cyanamide (lime nitrogen)

The pure product is a colorless hexagonal crystal. Industrial products are dark gray powder due to impurities such as carbon (graphite). Has the smell of calcium carbide or ammonia. Insoluble in water. It is a strong alkaline slow-acting nitrogen fertilizer.

When used as a fertilizer, because calcium cyanamide has strong alkalinity, it is suitable for acidic soil, and it is generally used as a base fertilizer, which has a certain soil improvement effect. When in contact with water it initially forms cyanamide, which is toxic to plants, but is quickly converted to ammonia. This poisonous effect causes plant leaves to fall off, so it can be used as a herbicide, fungicide, insecticide and cotton defoliant. In pesticides, it is mainly used to produce carbendazim, benomyl and intermediate cyanamide.