Question

In urea production, biuret is an undesirable product. As it causes leaf burning. Why does it cause burning of leaves?

Answer 1

Solution:

Biuret is the result of condensation of two molecules of urea and is a problematic impurity in urea based fertilizers. Reaction involved in biuret is

2NH₂CONH₂ → NH₂-CO-NH-CO-NH₂    +    NH₃

                                                                Urea                    Biuret                   Ammonia

Biuret is the impurity in the urea fertilizer which is very harmful to crops like pineapple, citrus, tobacco, and coffee. Biuret more than 1.5% in urea damage the roots of the plant and also useful bacteria which is essential to the growth of plants. Biuret also chock the capillary of the root cell. Biuret reduces the nitrogen carrying capacity of the plants. That's why leaf burning causes in plants also it leads to leaf chlorosis.