Storage and preservation basics for small farms

Post-harvest losses in India are estimated at 10 to 15 percent for grains and 25 to 40 percent for fruits and vegetables. Most of that loss happens between harvest and sale, in farms that lack basic storage infrastructure. Better storage is one of the highest-return investments a small farmer can make — every percent of crop you save is profit you keep.

Why store at all

Prices at the local mandi peak about 60 to 90 days after the major harvest, then again before the next planting season. If you can store for two to three months, you typically capture a 15 to 30 percent price premium over the post-harvest dump price. The storage cost is usually under 5 percent of the goods' value. The maths is obvious, but only if you have a place that keeps the crop in good condition.

For grains (wheat, rice, pulses, maize)

Drying first

Grains stored above 14 percent moisture content develop mould within weeks. Below 12 percent, they keep for 6 to 12 months without trouble. The single most important task before storage is drying — spread grain on a clean tarpaulin or pucca floor in direct sunlight, turn every two hours, and check moisture with a meter or a simple jar test (clean dry grain rattles; moist grain sounds dull and clumps).

Container choices

• Metal bin or kothi: durable, rodent-proof, holds 5 quintals to several tonnes. Lasts decades. ₹3,000 to ₹15,000 depending on capacity
• PICS bags (Purdue Improved Crop Storage): triple-layer airtight bags, kill insects naturally by depriving them of oxygen. ₹150 to ₹250 per 50 kg bag, reusable several times
• Hermetic Cocoons by GrainPro: large airtight tarp bags for tonnes of grain, 5 to 10 years of life
• Traditional clay or mud bins (kothla): work well in dry regions, free if you make them yourself, but vulnerable to rodents and moisture

Pest control without chemicals

Avoid heavy spraying of stored grain with pesticides — buyers may reject contaminated stock and chemicals on grain meant for human food are a serious safety risk. Better options:

• Neem leaves layered between bags repel weevils naturally
• Diatomaceous earth dusted lightly on grain works against many pests
• PICS bags or airtight containers starve insects of oxygen within 14 days
• Regular inspection: open one bag every 2 weeks and check for live insects, mould, or temperature increase

For potatoes and onions

These root vegetables can be stored for 3 to 8 months in cool, dark, dry, well-ventilated rooms. Most rural homes can spare one such room. Critical requirements:

• Temperature between 4 and 10 degrees Celsius for potatoes; 0 to 4 for onions (cool rooms in winter; small cold-store rental in summer)
• Humidity below 70 percent
• No direct sunlight
• Stack in plastic crates or jute bags, never in airtight plastic which traps moisture
• Remove sprouted or rotting bulbs immediately — one rotten onion can spoil a whole crate

For fruits

Most fruits have very short shelf life and are best sold within days of harvest. Some exceptions you can store:

• Apples — up to 6 months in cold storage (0 to 4°C). Several private cold storages in Himachal and J&K rent space monthly
• Pomegranates — 2 to 3 months in cool rooms
• Citrus (orange, sweet lime) — 4 to 6 weeks in cool conditions
• Bananas — only days; can be ripened in controlled chambers for staggered sales
• Mangoes — 2 to 3 weeks at 12 to 14°C; quality drops fast below this

Shared and rented cold storage

If you do not have your own cool room, every district in India has at least one private cold storage unit accepting small consignments. Rates are typically ₹1 to ₹3 per kg per month for fruits and vegetables, lower for grains. Insurance against power-cut damage is usually offered for an extra fee — take it.

Government cold storages (under NABARD-supported schemes) sometimes rent at subsidised rates. Ask your block agricultural officer for the nearest one.

Drying for longer shelf life

Drying is the simplest preservation method and works for many products:

• Solar drying of vegetables (cabbage, beans, tomatoes) extends shelf life from days to 6+ months
• Sun-dried chillies, turmeric, ginger, garlic — bedrock dried products in Indian agriculture
• Dried mango slices and amla — premium products that sell year-round at high margins

Simple solar dryers can be built for ₹3,000 to ₹10,000. Mahindra, KVKs, and several agri-tech start-ups sell improved versions that retain colour and nutrients better than open sun drying.

Decision rule

Store if you can hold the produce in good condition for at least 8 weeks, the expected price rise is more than 15 percent, and you do not have an urgent cash need. Sell immediately if storage conditions are poor, prices are stable or falling, or you need the money to buy seeds, pay labour, or service a loan.

There is no perfect answer — only the right answer for your particular crop, season, and circumstances.