Growing green manures is an age-old gardening technique that draws on a large range of fast growing crops to build, regenerate and maintain soil health. I like to think of it as growing soil instead of food – which is all the same thing really. Among the many benefits is this impressive list adapted from Green Harvest’s website: www.greenharvest.com.au/SeedOrganic/CoverCrops/GreenManureIntroduction.html
Green Manures:
- help prevent and treat soil disease
- increase organic matter, earthworms and beneficial microorganisms
- increase the soil’s available nitrogen and moisture retention
- stabilise the soil to prevent erosion – we’ve used them extensively on our steep banks directly after fresh earthworks, which has worked brilliantly
- bring deep minerals to the surface and break up hardpans – when you choose plants with deep taproots, such as lupins
- provide habitat for beneficial insects and reduce populations of pests
- improve water, root and air penetration in the soil
- can smother persistent weeds – good choices for weed suppression include lablab, cowpea, lucerne and buckwheat.