Question

which of the following help preserve soil fertility​

Answer 1

Answer:

Soil fertility can be further improved by incorporating cover crops that add organic matter to the soil which leads to improved soil structure and promotes a healthy, fertile soil; by using green manure or growing legumes to fix nitrogen from the air through the process of biological nitrogen fixation.

Answer 2

Answer:

U haven't given any options. So I have to give a guessed answer.

U can preserve soil fertility by  Multiple Cropping, Crop rotation and also by living that land uncultivated for a long time.