Green manuring practices

Green manuring practices

    1. Green manure crop can be grown in any type of soil provided there is sufficient rainfall or alternatively availability of irrigation water.
    2. For leguminous green manure crop, the seeds should be inoculated with the proper strain of bacteria.Molybdenum seed treatment could also enhance N fixation.
    3. The green manure crop should be sown with a higher seed rate than usual so that there will be a good canopy produced very quickly.

    Table: Seed rate and biomass production of green manure crops.

    Sl. No.

    Green manure crop

    Seed rate (kg/ha)

    Biomass yield (t/ha)


    Sunnhemp

    25-40

    21


    Daincha

    20-25

    26


    Cow pea

    25-30

    15


    Indigo

    25-30

    12


    Wild Indigo

    25-40

    16


    Green gram

    15

    10


    Black gram

    15

    10


    Cluster bean

    12-15

    10


      4. The production of green manures is limited by the deficiency of essential nutrients in the soil.
      5. The application of phosphatic fertilizers improves the growth of leguminous crop markedly and promotes the fixation of nitrogen by profuse nodulation.
      6. The best stage at which the crop should be incorporated into soil is when it reaches the flowering stage. For example sunhemp is ready for turning in at the age of 7-8 weeks whereas, daincha is ready for incorporation when it is 5-6 weeks old.
      7. Incorporation of green manure crops should be done at least 3-4 weeks before sowing or planting of main crop.
      8. Incorporation of green manure crop is done in the different ways. In some cases, the plants are cut close to the ground and the green material is put in the furrows opened by a mould board plough and is later buried. One of the methods is to plank the material down with a heavy plank or log and then plough the field. The other method is to mix the uprooted or cut plant material (green leaf manure) by means of disc harrow.
      9. Immediately after ploughing the material, care should be taken to cover it with soil by using suitable implements to ensure proper decomposition. Proper covering of material with the soil is especially necessary if the soil moisture supply is deficient.
      10. Under certain favorable circumstances, green manure crop such as dainchacan be sown in between the rows of main crops.When daincha is sufficiently grown, it can be uprooted and mixed with the soil by inter cultivation.
      11. Under limited moisture supply conditions, it is advisable to go for green leaf manuring by growing the green manure crops in one field and add the green material to another field.By adding this, the moisture required for growing the green manure crop is saved.

Table: Nutrient content of green manures.

      Sl.No.

      Name

      Nutrient content (%)

      Nitrogen

      Phosphorus

      Potassium


      Sunhemp

      0.89

      0.12

      0.51


      Daincha

      0.68

      0.13

      0.40


      Cowpea

      0.71

      0.15

      0.58


      Green gram

      0.82

      0.18

      0.52


      Black gram

      0.82

      0.18

      0.52


      Horse gram

      0.91

      0.18

      0.65


      Glyricidia

      0.68

      0.16

      0.30


      Pongamia

      0.16

      0.14

      0.49


Last modified: Friday, 6 January 2012, 7:03 AM