Why Cover Crops Belong in Tropical Seed Rotations
Why I Started Using Cover Crops
When I first advised growers to slot a cover crop between seed-corn cycles, the usual reaction was that it was one more cost with no cheque at the end. After six seasons of side-by-side strips, I’ve stopped having that argument — the soil does the talking.
The plots with a legume-grass mix over the fallow window held moisture longer into the dry spell and needed noticeably less starter nitrogen the following season.
What to Plant, and When to Cut It
There is no single recipe, but a mix beats a monoculture almost every time. Pair a fast legume for nitrogen with a fibrous grass for structure, and terminate before the cover sets seed so it never becomes next season’s weed.
- Sun hemp or cowpea for quick nitrogen
- A millet or sorghum-sudan for root mass and biomass
- Terminate at early flowering, never at seed set
- Leave residue on the surface — don’t bury it
The Payback
Cover crops are not a miracle, and the first season rarely pays for itself outright. But by the third cycle the compounding gains in infiltration, weed suppression and organic matter make the fallow window an asset instead of dead time.