Question

Why do farmers plant leguminous crops in crop rotations/mixed cropping?

Answer 1

Leguminous crops, also known as legumes are a type of plant that belongs to the family of Fabaceae or Leguminosae. These crops are produced agriculturally for their grain seed known as a pulse which is used as livestock forage and silage.

Complete answer:
Crop rotation is a consecutive process of farming a series of different types of crops in the same area across a sequence of production seasons. It causes a reduction dependency on nutrients, pest, and weed pressure. There is also a probability of developing resistant pests and weeds.
Harvesting the same type of crops in the same place for several years repeatedly in a row causes a gradual reduction of certain nutrients in the soil and selects for a highly competitive pest and weed community. The productivity of monocultures is depended on external inputs such as use of nutrients and it also affects diversity of pest and weed communities
Well-maintained crop rotation can decrease the need for synthetic fertilizers and herbicides rather it can use the ecosystem services from a diverse set of crops. The process of crop rotations can cause improvement in the nature of soil structure and organic matter.
Leguminous crops or legumes are a group of flowering plants which are grown for their grain fruit and seed. All pulses belong to leguminous crops. These crops are used as livestock forage and silage, and as soil-enhancing green manure. Leguminous crops are known for their nitrogen-fixing ability. Most of these crops bear symbiotic nitrogen-fixing bacteria in structures which are known as root nodules. Due to this reason, leguminous crops play a vital role in crop rotation and the farmers plant this in crop rotations/mixed cropping.
The symbiotic bacteria present in leguminous crops are known as Rhizobia and are found within root nodules of their root systems. These bacteria have the special ability to fix nitrogen from atmospheric, molecular nitrogen into ammonia.

Note: Crop rotation is a process of successive cultivation of a series of different types of crops in the same area. It is done for the purpose of improvement in soil quality. In leguminous crops, it contains symbiotic bacteria which is called Rhizobia, present within root nodules of their root systems. They are able to nitrogen-fixing in the soil, fix the atmospheric nitrogen into ammonia, and help in balancing the nitrogen amount of soil naturally.