Green Manures

Green manures are excellent source of nitrogen, even more micro nutrients. It is low cost manuring so it called as poor farmer's manure. It enhances the soil structure and organic matter in the soil. Excellent remedy for the alkaline and saline soils. It improves the soil fertility. It also prevents the nitrogen from soil erosion. It improves the soil aeration and organic matter content. It improves the soil structure. It stimulates the growth of beneficial microbes and other soil organisms. Green manures are playing effective tool in controlling weeds.

Other objectives of green manures:
It can be used as a catch crops, shade crops, forage, cover crops. So it has the multipurpose uses.

Types of green manuring:
1.Green leaf manuring crops
2.Green manuring in situ crops

Green leaf manuring crops:
It is raised in other location and collected the green biomass and added in to the soil. They have to be incorporated in the soil by fine ploughing. The crops should be cutted during the flowering stage. Some of the green leaf manure crops are ,

  1. Pongamia glabra (Pungam)
  2. Tephrosia perpuria
  3. Calotropis gigantia (Erukku)
  4. Gliricidia maculata
  5. Ipomea carnea
  6. Azadirachta indica (Neem)
  7. Leucaena leucocephala (Subabul)
  8. Cassia pistula
  9. Indigofera teysmannii

Calotropis gigantia (Erukku)

Tephrosia perpuria(Wild indigo)

2.Green manuring in situ crops
Crops are grown in situ and incorporated in the same field.The green manures are raised in the same field where going to cultivate the crop.It is mulched during the flowering stage. Some of the crops are,

1.Crotalaria juncea (Sun hemp)
2.Sesbania aculeata (Dhaincha)
3.Melilotus indica
4.Tephrosia perpuria(Wild indigo)
5. Sesbania rostrata(Manila agathi)
6. Vigna unguiculata(Cow pea)

Green manures incorporated in the soil

Another classifications are also there in green manures. They are,
    
1.Tree green manures:
Normally they are trees and cut their branches with their flowers and even fruits and put it in to fields and incorporated in to the soils. Some of the crops,  


Azadiracta indica,
Pungamia pinnata,
Glyricidia sps,
Thespesia populina,
Cassia seamia
   

Tree green manures(Azadiracta indica)

2.   Leguminous green manures:
Legumes have the ability to drive the nitrogen from air by their root nodules and fix it in to a form than can be used by plant . It can be used by crops after ploughed in to the soil.

Sunhemp (Crotalaira juncea)
Cowpea (Vigna unguiculata )
Dhaincha ( Seshania aculata)

Dhaincha ( Seshania aculata)

3. Non leguminous green manures:
It do not fix the nitrogen ,but it is fast growing crops and also increases the soil organic matter. Non legumes retain the nutrients in the soil from soil leaching. Some of the crops are,

Sunflower (Hellanthus annus)
Maize (Zea mays)
Jowar (Sorghum Vulgare)
Wheat (Triticum Sp)
   
Selection of green manures:
The crop should be fast growing and produce more green biomass. It can fix the nitrogen in the soil and suited for local climatic conditions. It should be tolerant to drought and flood conditions also.