What are the impacts of leguminous plants in rehabilitation of gypsum mined area?

Question

What are the impacts of leguminous plants in rehabilitation of gypsum mined area?

Answer 1

During mining processes you usually remove the topsoil of the land... the topsoil contains vital nutrients for plant growth.

One of these nutrients is Ammonium (a nitrogen containing molecule)

Not all plants can tranfer nitrogen into the soil, they need to have  certain bacteria growing in their roots. The plants that can do this are called legumes.

A first step in recovering topsoil is to grow legumes in the area, and then allow the natural plants to then invade the soil over the top of the legumes.

This process can take between 1 year and 50 years depending on the climate and the plants involved in the process.

Answer 2

There are nodes on the roots of leguminous plants. These nodes containn bacteria that fix Nitrogen from the atmosphere. the Nitrogen compounds so produced get into the plant for its metabolism. Also when the plant dies, acting like manure they enrich the soil with Organo-Nitrogenous compounds.

It is practice (in India) in heavily cropped lands (where 2crops are normally grown in a year) to sow seeds certain species of leguminous plants. After the crop matures it is tilled back into the soil, for fertilising it.