Article 23 · Soil & Compost
Cover Crops and Green Manures: Choosing Them for Your Growing Conditions
Understand when cover crops and green manures can protect soil or add biomass, and how to choose and terminate them responsibly.
A cover crop is grown mainly to protect or improve the soil rather than provide the main harvest. A green manure is a crop grown to return plant material to the soil; the terms can overlap.
At Bholi, limited fresh water makes the choice important. Living cover can be useful, but it also needs water, time and management.
Choose the purpose first
- Soil protection: Cover exposed ground during an otherwise bare period.
- Biomass: Produce material for surface cover or incorporation where appropriate.
- Nutrient capture: Take up nutrients that might otherwise be lost.
- Nitrogen contribution: Suitable legumes can fix nitrogen with compatible bacteria; the benefit depends on successful growth and nodulation.
- Root activity: Improve biological activity and, in suitable conditions, soil structure over time.
Cowpea, sunn hemp, horse gram, millet or other locally suitable species may be options. They do not perform identically, and a deep-rooted crop cannot be relied upon to break every compacted layer.
Plan how the crop will end
Before sowing, decide how you will cut or terminate it and prepare for the next crop.
- Match timing to the species, growth stage and next planting.
- Prevent unwanted seed production or regrowth.
- Account for water used by the cover crop.
- Allow for residue breakdown where necessary.
- Check suitability before allowing livestock to graze it.
There is no single flowering percentage or waiting period that suits every crop and climate. Begin with a manageable trial and record the outcome.