Q. Which of the following are nitrogen-fixing plants?

  1. Alfalfa
  2. Amaranth
  3. Chickpea
  4. Clover
  5. Purslane (Kulfa)
  6. Spinach

Select the correct answer using the code given below:

  • 1, 3 and 4 only
  • 1, 3, 5 and 6 only
  • 2, 4, 5 and 6 only
  • 1, 2, 4, 5 and 6

Answer: (a) 1, 3 and 4 only

Notes:

  • Nitrogen fixation is a process that implies the transformation of the relatively non-reactive atmospheric N2 into its more reactive compounds (nitrates, nitrites, or ammonia).
  • Nitrogen fixation is the essential biological process and the initial stage of the nitrogen cycle.
  • In this process, nitrogen in the atmosphere is converted into ammonia (another form of nitrogen) by certain bacterial species like Rhizobium, Azotobacter, etc., and by other natural phenomena.
  • Nitrogen-fixing plants are those that have roots colonized by specific kinds of bacteria with the ability to extract nitrogen from the air and convert it to a usable form of nitrogen that can be used to help them grow.
  • Nitrogen-fixing plants contribute an essential plant nutrient that’s necessary for healthy fruit and foliage production.
  • Alfalfa should also be dubbed the “King of Nitrogen Fixation” because it makes more residual nitrogen available to subsequent crops than any other legume you can grow.
  • Chickpea plays a significant role in improving soil fertility by fixing atmospheric nitrogen.
  • Red Clover ( Trifolium Pratense) is a nitrogen-fixing perennial plant that produces showy red, purple, or pink flowers in late spring or summer.
  • Amaranth species are cultivated as leaf vegetables, pseudocereals, and ornamental plants. Most of the Amaranthus species are summer annual weeds and are commonly referred to as pigweeds.
  • Purslane is an annual succulent that has been considered both a useless weed and a powerful medicinal plant at different times throughout history.
  • Spinach, also known as Spinacia oleracea, is a member of the Amaranthaceae family. 

Nitrogen-fixing cover crops bring multiple benefits to farmers:

  • participate in N fixation;
  • protect soil from erosion by covering it or holding in place with strong root systems;
  • improve soil fertility when used as green manure;
  • retain soil moisture;
  • help in weed management with crop residues;
  • serve as forage and grazing material for poultry and cattle;
  • attract pollinators at the crop flowering time.