Cardamom grown under somebody else's trees

A cardamom garden in Sikkim does not look like a field. It looks like woodland that somebody has been weeding. There are tall trees, a closed canopy, leaf litter on the ground, and under it all, knee-high clumps of a broad-leaved plant whose capsules are dried over woodsmoke until they turn the colour of a bicycle tyre.

That appearance is not neglect. It is the specification. Large cardamom will not grow in full sun, and it will not grow on ground that has been cleared and fenced and ploughed. It needs shade of roughly half to two-thirds, a soil that stays damp but never sits wet, and — this is the part that changes the economics — a supply of nitrogen that nobody has to buy.

Two storeys, one budget

The tree that does the work is the Himalayan alder, Alnus nepalensis. It is a nitrogen fixer: bacteria in nodules on its roots pull nitrogen out of the air and make it available in the soil. Measured in these systems, an alder stand puts down around 52 kilograms of nitrogen per hectare a year at five years old, peaks near 155 at fifteen, and settles back to something under 60 as the stand matures. It also drops its leaves, which are high in nitrogen and break down fast, and it holds the slope together with roots that go deeper than a cardamom clump ever will.

So the plot is not one crop. It is two, in different storeys, on different clocks — and the tree's product is not sold. It is spent on the crop underneath.

Why expanding the crop meant planting trees

This is the reason a century of cardamom in Sikkim did not cost a century of forest. To grow more cardamom, a household does not clear a slope. It plants alder on a slope, waits five or six years for the canopy and the nitrogen to arrive, and puts the suckers in underneath. The crop arrives second, into a system that is already running.

Which means the forest here is not what was left over after farming. It is a working part of the farm, maintained at a density and a species mix chosen by farmers for reasons that are entirely commercial. The mountain looks wooded because the economics require it to be wooded. Where the tree has been cut for timber or for firewood, the cardamom underneath declines within a few seasons, and the farmer learns the same lesson again.

It is worth stating how unusual this is. Across most of the tropics, a cash crop is the reason forest goes down: the crop is planted in the clearing, and the timber sale pays for the clearing. Here the cash crop is the reason the canopy stays up, and the canopy is not a protected area, a sacred grove or a government plantation. It is a production input, owned by the household, with a job.

What broke

Since the early 2000s the system has been failing, and it is failing from the inside rather than from the edge. Two viral diseases — chirkey, which streaks and stunts the leaves, and foorkey, which turns a clump into a dense, barren bush of small shoots — have spread through the gardens, along with a fungal leaf blight and a rhizome rot that kills the clump at the collar. None of them have a cure once a clump is infected. The only response is to rogue it out, dig up the rhizome and burn it.

The epidemic found a crop with very little genetic variation to work with. Large cardamom is propagated from root suckers, which means every plant in a garden is a clone of the one beside it. That gives fast, uniform establishment and it gives a pathogen a single genetic target. Add a run of warmer winters and more erratic rain — the crop wants 3,000 to 3,500 mm spread over about 200 days — and a plant that used to yield for thirty years now yields for five or six and then dies.

The arithmetic of that is brutal for a perennial. A smallholder who replants is waiting four years for the first harvest from a plant that may only give three. The state's area figures record the result: roughly 25,000 hectares down to about 12,500, output from 5,152 tonnes to around 2,500. India's share of world production fell from about 85 per cent to around 22, while Nepal — same crop, same mountains, better planting material — went to 68.

The price is why anybody still plants it

And yet the gardens have not been abandoned, and the reason is a single number. Cured capsules have gone from roughly ₹400 a kilogram in the mid-2000s to around ₹2,300. A farmer whose yield has halved and whose plants die in five years is still, at that price, running a business worth continuing — barely, and with a replanting debt that has to be carried for four years before it pays anything.

That combination explains a pattern you can see across the district: the old gardens are being kept alive by replanting in the gaps, rather than replaced. Nobody is clearing and starting again, because clearing means losing the trees, and the trees take as long as the crop to mature. Instead, suckers go into the spaces where a clump has died, the canopy is left standing, and the garden becomes a patchwork of plants of different ages — which is harder to manage, spreads the harvest, and spreads the risk.

A crop you cannot value by the hectare

This is the practical point, and it applies well beyond cardamom. The standard way to value a crop is area times yield times price. For an understorey perennial, all three terms are downstream of a fourth: the age and density of the trees above it. Two gardens of the same size, on the same slope, can differ by a factor of two in output because one has a fifteen-year alder stand and the other has a stand that was thinned for firewood three winters ago.

Which means the honest unit here is not the hectare. It is the hectare-year, counted from when the trees went in. A cardamom garden is a slow asset with a fast crop planted inside it, and every decision about it — whether to replant, whether to cut, whether to sell the land — is a decision about the tree, dressed up as a decision about the spice.