Growing Green Manure

Latest Update 27th August 2017.

Green Manure Mix
  • Every year one of my Ecobeds grows a crop of green manure.  Its part of my 4 year crop rotation and the field peas, oats and vetch it contains follow the brassicas
  • Brassicas are heavy feeders and strip soluble nutrients from the soil, so its important to build up the soil's fertility before planting the next crop of potatoes.
  • The seeds are supplied with a nitrogen fixing bacterial inoculant to help the legumes in the mix to start fixing nitrogen.
  • Its also very useful to give the soil in my Ecobeds this extra fertility boost every 4 years. 
  • The green manure is planted in autumn and harvested in mid winter.  Its chopped down to the ground and shredded before being returning to the bed as mulch.
  • Its covered immediately with a generous layer of compost topped with sugar cane straw to keep it moist, and is left for 6 weeks to break down.
  • This green manure mix provides all the nitrogen fixing benefits conferred by legumes and bulk foliage to raise the soil's organic content when it rots down.  
  • The nitrogen fixed by legumes is in a plant available form and is an excellent soil amendment.  Surpluses are stored in the plant's root nodules and I leave them in the ground to be used by following crops.  
Details.
  • Varieties                                                     Pisumsativum, Vicia villosa, Avena sativa. 
  • Garden bed type:                                         Garden Ecobed.
  • Recommended soil pH                                 6.0 - 8.0.
  • Minimum Sun per Day:                                 6 hours.
  • Plant Spacings (centres)                              Broadcast.
  • Weeks to Harvest                                        14 weeks.
  • Climate:                                                      Warm Temperate.
  • Geographic Hemisphere:                               Southern.
Growing Conditions.
  • Green manures like this one need full sun and are planted in early autumn.
  • Properly managed Ecobeds provide ideal growing conditions for green manures including constant moisture and high worm and microbial population in the soil.
Soil Preparation.
  • Clear a space for the green manure in autumn by removing old mulch, dead leaves and unwanted organic material.
  • Apply a 60mm top dressing of homemade compost and cover with straw mulch.
  • Leave the bed for at least 4 weeks to build up worm and microbial activity.
Growing Instructions.
  • Remove the straw mulch.
  • Sow (broadcast) green manure seeds directly onto the Ecobed's soil in April.  Apply it at the rate recommended by your seed supplier.
  • Lightly rake the seeds into the surface and water them in with the bacterial inoculant supplied to ensure nitrogen fixing occurs.
Harvesting.
  • Cut the green manure down to ground level with garden shears.
  • Shred the foliage and return it to the bed as mulch.  Leave the roots in the soil.
  • Cover it with a 60mm layer of compost with straw mulch on top.
  • The green manure is usually ready by mid July, about 6 weeks before I sow my potatoes. 
Organic Pest Control.
  • Because its a cool season crop, I have never had disease in my green manure.
  • High levels of organic material are maintained in the soil using homemade compost, which keeps the worms and beneficial microorganisms very active and protects the plants against soil-borne pests.
  • Regular monthly foliar sprays of aerated compost tea boosts beneficial microbial activity on the plants' above ground tissue.  This activity helps protect the green manure against airborne pests.
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