Why is salt sometimes used to kil weeds?

Answer 1

Salt can be used to kill weeds in the context that if you water a strong solution of salt water on a row of seedling beetroot in strong sunlight the sun will kill everything else apart from the beetroot because the beetroot family are classed as 'maritime' plants i.e. they originated from the coastline and are resistant to salt water whereas other plants are not and the salt will kill them, using salt in this way is known as a 'selective herbicide'