Identify the correct statement:

1. Good drainage facilitates the ready diffusion of oxygen to the root zone and escape of carbon dioxide from the root zone into the atmosphere.
2. Toxicity in acid soils due to excess iron and manganese is increased by drainage
3. Drainage permits roots to grow deeper and spread wider thereby decreasing the volume of soil from which nutrients can be extracted.
4. The provision of a good drainage system doesn’t permit the removal of excess salts in the soil