Question 24

The Government of India promotes the use of 'Neem-coated Urea' in agriculture primarily for the following reason:

Neem coating acts as a nitrification inhibitor. When urea is applied to the soil, it quickly gets converted into ammonia and then nitrates (a process called nitrification) by soil bacteria. Nitrates are prone to leaching (washing away) and denitrification (conversion into nitrogen gas, including nitrous oxide, which is a greenhouse gas), leading to significant loss of applied nitrogen. Neem coating slows down this nitrification process, thus slowing the release of nitrogen from urea. This makes nitrogen available to the crops for a longer period, improving 'nitrogen use efficiency' and reducing the loss of nitrogen to the environment. This means less urea is needed for the same yield, or higher yields can be achieved with the same amount of urea, and environmental pollution is reduced.

• Option A is incorrect: Neem oil does not directly increase nitrogen fixation by soil microorganisms; its primary role here is to inhibit nitrification.
• Option C is incorrect: While neem coating reduces the release of nitrous oxide by slowing nitrification, it does not mean 'not at all released'. It significantly reduces, but not completely eliminates, the release.
• Option D is incorrect: Neem-coated urea is a fertilizer with modified release properties, not a combination of weedicide and fertilizer.