Analyzing the statements below:

1. The application of certain organic compounds can cause nitrogen deficiency due to immobilization.

2. Nitrogen fertilizers are very acidifying due to nitrification.

3. In reducing environments, such as flooded soil, we should avoid applying nitrogen fertilizers based on nitrate to prevent leaching.

4. Ammonium nitrate is a nitrogen fertilizer that undergoes the greatest losses due to volatilization, so it is recommended to incorporate it after application.