Which of the following statements is/are correct with regard to...

Nitrolim is a mixture of calcium cyanamide (CaCN_2$) and carbon (C$).

It is prepared by heating calcium carbide with nitrogen gas at a high temperature.
$CaC_2 + N_2 \rightarrow CaCN_2 + C$
Thus, statement I is correct.

In the soil, nitrolim reacts with moisture to release ammonia gas, which provides nitrogen to the plants.
$CaCN_2 + 3H_2O \rightarrow CaCO_3 + 2NH_3$
Thus, statement II is correct.

Nitrolim provides only nitrogen to the soil, making it a nitrogenous fertilizer, not an NPK fertilizer. Thus, statement III is incorrect.

Nitrolim is an inorganic fertilizer, not an organic fertilizer. Thus, statement IV is incorrect.

Therefore, only statements I and II are correct.

Answer: I and II only