Cultivation | Farming Techniques | Soil Type | Temperature | Watering | Fertilization | Mulching | Nitrogen Fixing
Nitrogen-fixing trees (NFTs) are species that form symbiotic relationships with nitrogen-fixing bacteria (mainly Rhizobium, Frankia, or Bradyrhizobium) in their root nodules, allowing them to convert atmospheric nitrogen (N₂) into a form usable by plants (ammonium NH₄⁺). These trees improve soil fertility, support sustainable agroforestry, and reduce dependence on chemical fertilizers.
Why Are Nitrogen-Fixing Trees (NFT) Important?
- Improve Soil Fertility
- They naturally add nitrogen to the soil, which benefits adjacent crops like agarwood, cinnamon, or citrus.
- Support Sustainable Agriculture
- NFTs reduce the need for chemical fertilizers and help maintain long-term soil productivity.
- Enable Agroforestry Systems
- They serve as companion plants in multi-strata farming — boosting both yield and resilience.
- Prevent Erosion & Restore Land
- Their deep root systems stabilize the soil, making them perfect for slope rehabilitation and degraded lands.
- Provide Additional Resources
- Many NFTs offer fuelwood, fodder, green manure, mulch, and even edible flowers or medicinal uses.
| Scientific Name | Common Name | Nitrogen-Fixing Partner | Uses & Notes |
|---|---|---|---|
| Erythrina variegata | Dapdap / Tiger’s Claw | Rhizobium spp. | Soil enrichment, shade tree, medicinal |
| Pterocarpus indicus | Narra | Rhizobium spp. | National tree; timber, medicinal, ornamental |
| Sesbania grandiflora | Katuray / Turi | Rhizobium spp. | Edible flowers/leaves, medicine, fast-growing |
| Acacia confusa | Formosan Acacia | Rhizobium spp. | Soil stabilization, reforestation, fast-growing |
| Calliandra portoricensis | Calliandra (native form) | Rhizobium spp. | Forage, soil enhancement, bee forage |
| Mimosa pudica (shrub) | Makahiya | Rhizobium spp. | Ground cover, medicinal (caution: invasive in some areas) |
| Albizia procera | White Siris | Rhizobium spp. | Reforestation, soil improvement, light timber |
| Leucaena leucocephala¹ | Ipil-ipil | Rhizobium spp. | Forage, firewood, hedgerows (naturalized but widely used) |
| Gliricidia sepium¹ | Madre de cacao | Rhizobium spp. | Green manure, shade tree, fencing (introduced but naturalized) |
Pro Tips for Integration
- Spacing: NFTs should be spaced based on their canopy and root spread. Avoid planting them too close to slow-growing or shade-sensitive crops.
- Pruning Routine: Regular pruning encourages root nodulation and controls shade levels.
- Leaf Mulching: NFT leaves are nutrient-rich—perfect for mulching around Agarwood, Nutmeg, and Citrus.
Inoculation Reminder:
For maximum nitrogen fixation, inoculate NFTs at planting with Rhizobium or Frankia-based biofertilizers (depending on species). This boosts early root symbiosis and long-term productivity.
The Big Picture
NFTs are powerful tools for climate-smart agriculture, reforestation, and regenerative plantation design. They form the backbone of ecologically sound and economically productive landscapes.