Closing the Loop: Turning Cover Crops into Compost and Soil Fertility
Introduction — Why Cover Crops Matter for Market Gardeners
Cover cropping is one of the most powerful tools a market gardener can use to protect and enrich soil, increase fertility, and reduce labour. At Roebuck Farm in Taranaki, we’ve been experimenting with different cover cropping methods this season — from simple hand tools to advanced seeders — to see how we can get the best results with the least work. In this post, I’ll share the tools we use, the techniques we’ve developed, and the lessons we’ve learned, so you can adapt them for your own farm or garden.
Tools for Efficient Cover Cropping: From Rakes to Jang Seeders
When we first began farming, all we had was a rake and a domestic fork. Our process was straightforward: prepare the soil surface, broadcast seeds by hand, and rake them in. It worked, but it was physically demanding.
Today, we use a range of seeders — including a six-row, single-row Jang, and five-row Jang — to plant most of our cover crops. This year, most of our outdoor beds have gone into mixed cover crops with very little preparation, thanks to these tools.
With the economy in New Zealand in a deep recession, we’re always looking for ways to skip steps without compromising principles. This year, we did no traditional bed preparation — just a light cultivation of the top 4–5 cm using a Tilther before seeding.
Step-by-Step: Establishing Diverse Cover Crops with Minimal Prep
Here’s how we approached this season’s cover crops:
- Mixed grains: planted with the five-row Jang seeder using four grain types with an R24 roller.
- Lupins: manual broadcasting first (since lupin seeds don’t run well in the hopper), lightly covered, then overseeded with the five-row Jang.
- Small seeds (e.g., phacelia, agricultural mustard): sown afterwards with the six-row seeder to keep seed sizes separate and ensure even coverage.
We’ve found that using different seeders for different seed types and sizes creates a healthier, denser crop stand.
Handling Different Seeds: Practical Techniques for Better Coverage
Not every grower will have access to multi-row seeders. But you can still get great results with minimal equipment. A push hoe or wheel hoe can scuff the soil surface before broadcasting seed by hand. Follow up by raking in the seed, watering, and covering with 70% shade net to protect the soil, retain moisture in summer, and shield young seedlings from heavy winter rain.
We also trialled different beans this year: broad beans manually seeded and tic beans — a smaller, highly productive variety — direct seeded with a Jang using an A12 roller. These approaches show that knowing your tools and seed types is key to efficient cover cropping.
Closing the Loop: Turning Cover Crops into Compost and Soil Fertility
The big question now is: what do we do with these cover crops? Options include crimping and tarping, transplanting through the cover crop, or letting them mature to build soil carbon.
At Roebuck Farm, we’re leaving most cover crops to mature. Once pulled, they’ll be composted and cycled back into the soil. Right now, our greenhouses are freshly composted and ready for summer crops — compost made from last season’s cover crops, garden waste, horse manure, and organic silage and hay sourced locally.
This closed-loop system is what makes cover cropping so powerful: it not only protects the soil but builds fertility year after year.
Final Thoughts
Cover cropping isn’t just a soil management technique — it’s a strategy that can transform your farm or garden. Whether you’re working with nothing but a rake or investing in specialised seeders, matching your approach to your tools, labour, and timing will make all the difference.
With planning and the right techniques, cover crops can be simple, effective, and regenerative.
