Instructions for improving orchard land in coffee rotation

Rotating crops before replanting coffee helps reduce nematodes, mycorrhizal fungi and restores soil organicity. Instructions for uprooting old orchards, treating roots, applying lime, planting legumes and evaluating soil before replanting.

Summary: Land reclamation is the most annoying part of coffee replanting because it takes time and there is no immediate coffee income. But this is also the part that decides whether the new tree will live or die. Old coffee orchard soil often accumulates nematodes, mycorrhizal fungi, rotten roots and organic loss. This article guides the 12-36 month process of cleaning and restoring the soil before replanting.

Applies to: Old coffee orchards with low productivity, with yellow leaves, root rot, nematodes or scattered dead trees.
Duration: 1-3 years depending on soil disease level.
Difficulty level: Advanced. It takes patience, taking notes and testing the soil.
Estimated additional costs: 30-80 million VND per hectare per year, part of which can be compensated by short-term rotation crops.

Why do we have to rotate crops

After 20-30 years of growing coffee, orchard land often has problems:

Old coffee roots remain in the soil, carrying fungal diseases.
Root nematodes accumulate around old roots.
The soil is compacted due to many years of walking, watering, and fertilizing.
Organic content is reduced, beneficial microorganisms are weak.
Soil pH decreases, nutrients are unbalanced.

If the old orchard is uprooted and then replanted immediately, the young tree must live in the same land that caused the old tree to decline. Therefore, crop rotation is not a general "resting of the soil" but a process of proactively reducing disease sources and restoring soil structure.

Evaluate land before renovation

Before uprooting the old orchard, it is necessary to record:

orchard age and productivity in the last 3 years.
Proportion of plants with yellow leaves, root rot, and dry death.
Low land, dry areas, areas with local bad trees.
Previous fertilizer, lime, and organic fertilization schedule.
Soil analysis results, if any: pH, organic matter, nematodes.

If the orchard has yellow leaves and root rot above 20 percent, crop rotation should be at least 2 years. If the disease is mild and the soil is still good, you can rotate crops for 1 year but still need to check again before sowing.

Properly uproot the old orchard

Pull out all the roots

Use a machine or tool to pull both the base and main roots.
Collect large roots, diseased roots, and remaining branches and leaves.
Do not plow diseased roots back into the soil.

Old coffee roots are where nematodes and fungi exist. The more you miss, the riskier replanting becomes.

Plow deeply and expose the soil

Plow or till 30-40 centimeters deep.
Dry the soil during the dry season for 1-2 months if conditions allow.
Turn the soil 1-2 times to expose remaining roots and decompose faster.

Sunshine and drought help reduce some pathogens and loosen the soil.

Apply lime

Apply 1-2 tons of lime per hectare depending on soil pH.
Spread evenly and mix into the topsoil.
Pre-fertilize organic and rotate crops at least 15-20 days.

Do not consider lime as a treatment. Lime is just one part of the soil improvement package.

Choose crop rotation

Legume family

Highest priority:

Soybeans.
Peanuts.
Green beans.
Yellow flower bed, green manure plant.

Benefits: covers soil, increases organic matter, supports nitrogen fixation, helps soil loosen.

Corn or other short-term crops

Can be used to earn income while waiting:

Corn is easy to sell, easy to grow.
Vegetables should only be grown if treatment and water are managed well.
Do not choose plants that also have severe nematodes if the orchard needs to reduce nematodes.

Trees should not be planted during the renovation period

Pepper, cocoa, perennial plants with deep roots are difficult to remove.
Trees have high water needs, causing more soil depletion.
The tree causes orcharders to delay replanting without properly renovating on target.

Organic and Microbiological Management

Each year of renovation, additional additions should be made:

Manure or compost: 15-30 tons per hectare depending on conditions.
Coffee peels have been composted, do not use fresh peels and pour thickly close to the roots.
*Trichoderma* product mixed with decomposed organic matter to support resistance to soil fungi.
Legume residue plowed when still green.

Organic must be spoiled. Introducing unrotted material into the soil can heat the soil, trap fungi and cause temporary nitrogen loss.

Suggested renovation schedule

Year 1

Uproot the old orchard, collect the roots.
Plow deeply, expose the soil.
Lime.
Plant legumes at the beginning of the rainy season.
After harvesting, plow the stems and leaves or add compost.

Year 2

Continue to grow crops in rotation.
Organic supplements.
Take samples of soil and roots of rotation crops to check for nematodes if the orchard has had serious diseases.
Improving ditches, water lines, lot banks.

Year 3 if needed

Additional crop rotation with severely diseased orchards.
Check the soil one last time before digging the coffee hole.
Only sow seeds when the soil has clearly reduced risks.

Signs the land is ready

The land can be prepared for replanting when:

The soil is loose, there are not many old coffee roots left.
pH improved to suitable level.
Increased organic content, soil retains moisture better.
No more dead/unusual yellow areas of rotation crops.
The nematode population decreased to a level acceptable to local technicians.

If in doubt, try growing a small batch first. Test plants will expand after 3-6 months of good response.

Common mistakes

Pluck the tree but leave the roots behind: the source of the disease is still in the soil.

Rotate crops with just one crop for good measure: seriously diseased soil requires a longer period of time.

Unrefined organic fertilizer: heats the soil and increases the risk of fungus.

No soil analysis: decide to sow according to feeling.

Grow other perennials in the meantime: lose the renovation goal to return to coffee.

Take notes

[ ] Date of uprooting old orchard, amount of roots collected.
[ ] Amount of lime, organic matter, and phosphorus applied.
[ ] Crops are rotated each season, yield and biomass are returned to the soil.
[ ] Results of soil analysis before and after renovation.
[ ] The land is still bad or the rotation crops grow poorly.

The more carefully you record, the less risky the replanting decision will be. This is an investment for 20 years of a new orchard.