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Green Manuring

Submitted by admin on Mon, 08/10/2009 - 20:37

Green manuring

It is the practice of growing crops (mostly leguminous) that contribute important nutrients in a particular soil and incorporating the biomass in the same soil so that nutrient needs of the future crop are met. Crops grown for green manuring purpose are called green manure crops. These crops are allowed to grow till they reach flowering stage and then plough back in the soil because before reaching flowering stage maximum quantity of biomass would have already been produced and if the crop is allowed to complete its life cycle beyond that point, it would consume the nutrients that it has already generated.

Some legume crops suitable for green manuring are Horsegram, Dhaincha (Sesbania aculeata), Sunhemp (Crotalaria juncea), Cowpea (Vigna mungo), Pea (Pisum sativum), Berseem, Blackgram, Beans, Pillipesara (Phaseolus trilobus), Kalonji or Wild indigo (Tephrosia purpurea) etc.

Some non-legume crops suitable for green manuring are Mustard, Wheat, Jowar, Maize, Sunflower etc

Important characteristics of green manure crop:

  • It should provide large quantities of biomass
  • It should quickly disintegrate in the soil after incorporation
  • It should be having the ability to acquire nutrients that are otherwise not in available forms
Crop Sowing time Seed rate (kg/acre) Biomass produced
(ton/acre)		 nitrogen contributed
(kg/acre)

 

 Remarks
Berseem Oct-Dec 32-40 8-9 27-28  
Blackgram Jun-Jul 8-9 3-4 15-19  
Beans Apr-Jul 8-9 4-5 16-19  
Cowpea Apr-Jul 18-22 6-7 30-35  
Daincha Apr-Jul 32-40 6-7 33-42 High biomass, wide adaptability. good in
saline soils also
Greengram Jun-Jul 12-16 8-10 27-34  
Horsegram Jun-Jul 10-12 10-12 48-54  
Peas Oct-Dec 4-5 3-4 10-13  
Sunhemp Apr-Jul 32-40 6-10 24-40 Quick growing, easy seed production
Sesbania rostrata     10 87 Stem nodulating, tolerant to water
logging
Kalonji / Wild indigo     6-7 46 Drought tolerant, self seeding
Pillipesara     7 50 Green manure crop cum fodder crop