Introduction
Good crop yields depend not only on quality seeds and good management but also on the right fertilizers. Fertilizers can serve different purposes: some improve the soil, some feed plants directly, and others help plants grow stronger and healthier. Knowing the different types helps farmers use them wisely for both short-term productivity and long-term soil health.
🌱 1. Fertilizers to Improve the Soil (Organic Fertilizers)
- Build soil fertility, structure, and water holding capacity. This fertilizer is mainly used as basal application.
- Examples: Compost, animal manure, green manure, rice straw, biochar.
🌾 2. Fertilizers to Feed Plants through Roots (Soil Application)
- Supply nutrients that root absorb for plant growth. These fertilizers used as basal and at different stages of crop growth.
- Examples: Urea, DAP, NPK, potassium chloride, lime.
- Applied before planting or during crop growth.
🍃 3. Fertilizers to Feed Plants through Leaves (Foliar Application)
- Provide quick nutrients directly through leaf absorption.
- Examples: Zinc, boron, iron sprays, liquid NPK, fish amino acid.
- Useful for deficiency correction or rapid growth boos
🌿 4. Fertilizers as Biostimulants (Support Growth & Resistance)
- Stimulate root development, photosynthesis, and stress resistance.
- Examples: Seaweed extract, humic acid, amino acids, banana peel extract, rice whisky extracts.
- Often used in small doses, sometimes with foliar sprays.
🦠 5. Biofertilizers (Beneficial Microbes for Plants & Soil)
- Introduce living organisms that help crops absorb nutrients and fight disease.
- Examples: Rhizobium, Azospirillum, Mycorrhiza, Trichoderma
- Applied to soil, seeds, or roots; best when soils are not overloaded with chemicals.
Conclusion
Each type of fertilizer plays a different but complementary role. Farmers should not rely on only one kind. By combining organic fertilizers (for soil health), soil and foliar fertilizers (for direct nutrition), biostimulants (for growth), and biofertilizers (for living soil biology), farmers can achieve healthy soils, strong crops, higher yields, and sustainable farming.
Guide for Commune Agriculture Officers (CAO)
By Yang Saing Koma,(MAFF, Cambodia)
September 2025