Physical change hope this helps
Ploughing and turning over the soil aerates the soil so the roots of plants are able to thrive well. Ploughing the roots of leguminous plants back to the soil returns nutritents and organic matter to the soil organically rather than using synthetic fertilisers which are potentially hazardous to the environment.
Answer:
to avoid mutations and other issues that may occur
This is true, for it is called redshift
