Organic Farming :: Organic Inputs and Techniques

Green Manure

Neem Use and Potential in Organic Agriculture new

Green Manure

Green undecomposed material used as manure is called green manure. It is obtained in two ways: by growing green manure crops or by collecting green leaf (along with twigs) from plants grown in wastelands, field bunds and forest. Green manuring is growing in the field plants usually belonging to leguminous family and incorporating into the soil after sufficient growth. The plants that are grown for green manure known as green manure crops. The most important green manure crops are sunnhemp, dhaincha, pillipesara,clusterbeans and Sesbania rostrata.

Biomass production and N accumulation of green manure crops

Crop Age (Days) Dry matter (t/ha) N accumulated
Sesbania aculeata 60 23.2 133
Sunnhemp 60 30.6 134
Cow  pea 60 23.2 74
Pillipesara 60 25.0 102
Cluster bean 50 3.2 91
Sesbania rostrata 50 5.0 96

Nutrient content of green manure crops

Plant Scientific name Nutrient content (%) on air dry basis
N P2O5 K
Sunhemp Crotalaria juncea 2.30 0.50 1.80
Dhaincha Sesbania aculeata 3.50 0.60 1.20
Sesbania Sesbania speciosa 2.71 0.53 2.21

Sesbania rostrata is a stem nodulating green manure crop which is a native of West Africa. As it is a short-day plant and sensitive to photoperiod, the length of vegetative period is short when sown in August or September. A mutant (TSR-l) developed by Bhabha Atomic Research Centre, Bombay is insensitive to photoperiod, tolerant to salinity and waterlogged condition. Growth and nitrogen fixation is higher with TSR-l compared to the existing strains.

Advantages

  1. Improves soil structure
  2. Increases water holding capacity and
  3. Decreases soil loss by erosion

GREEN LEAF MANURE

Application of green leaves and twigs of trees, shrubs and herbs collected from elsewhere is known as green leaf manuring. Forest tree leaves are the main sources for green leaf manure. Plants growing in wastelands, field bunds etc., are another source of green leaf manure. The important plant species useful for green leaf manure are neem, mahua, wild indigo, Glyricidia, Karanji (Pongamia glabra) calotropis, avise(Sesbania grandiflora), subabul and other shrubs.

Green Leaf Manure

Nutrient content of green leaf manure

Plant Scientific name Nutrient content (%) on air dry basis
N P2O5 K
Gliricidia Gliricidia sepium 2.76 0.28 4.60
Pongania Pongamia glabra 3.31 0.44 2.39
Neem Azadirachta indica 2.83 0.28 0.35
Gulmohur Delonix regia 2.76 0.46 0.50
Peltophorum Peltophorum ferrugenum 2.63 0.37 0.50
Weeds
Parthenium Parthenium hysterophorus 2.68 0.68 1.45
Water hyacinth Eichhornia crassipes 3.01 0.90 0.15
Trianthema Trianthema portulacastrum 2.64 0.43 1.30
Ipomoea Ipomoea 2.01 0.33 0.40
Calotrophis Calotropis gigantea 2.06 0.54 0.31
Cassia Cassia fistula 1.60 0.24 1.20

Advantages

  1. Green manuring improves soil structure, increases water holding capacity and decreases soil loss by erosion.
  2. Growing of green manure crops in the off season reduces weed proliferation and weed growth.
  3. Green manuring helps in reclamation of alkaline soils. Root knot nematodes can be controlled by green manuring.

 

Source

  1. http://pics.davesgarden.com/pics/Farmerdill_1153916472_551.jpg
  2. http://www.tropicalfruitandveg.co.uk/images/guar.jpg
  3. http://img.photobucket.com/albums/v686/Chimanlal/ClusterBean02Guar.jpg
  4. http://www.rostrata.co.uk/images/photos/rostrata_plant.jpg
  5. http://florabase.calm.wa.gov.au/science/timage/14737ic1.jpg
  6. http://www.mytho-fleurs.com/images/Fleurs_du_Vietnam/Calotropis_gigantea.jpg
  7. http://www.agric.wa.gov.au/ikmp/images/parthenium.gif
  8. http://www.metafro.be/prelude/prelude_pic/Peltophorum_africanum2.jpg
  9. http://gardendigger.com/images/toptropicals/3/3972.jpg
 

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