Get to Know 5 Types of Fertilizer and Their Functions for Plants!
Soil fertility is one of the key factors in successful agricultural cultivation. Plants require a variety of essential nutrients to grow and develop optimally. However, not all soils can provide these nutrients in sufficient quantities. This is where fertilizers play a crucial role, as an additional source of nutrients needed by plants.
Proper fertilization can increase productivity, improve crop quality, and enhance plant resistance to pests and diseases. This article outlines the common types of fertilizers used in agriculture and their specific functions for plants. Here are the types of fertilizers:
- Inorganic (Mineral) Fertilizers
- Organic Fertilizers
- Compound Fertilizers
- Slow-Release Fertilizers
- Liquid and Foliar Fertilizers
1. Inorganic (Mineral) Fertilizers
Inorganic fertilizers contain nutrients in the form of inorganic chemical compounds, usually produced industrially from natural raw materials such as natural gas, air, or mineral ores. Their advantages include high nutrient content, high solubility, and fast availability to plants. Common types of inorganic fertilizers include:
a. Nitrogen (N) Fertilizers
Nitrogen fertilizers are single-nutrient fertilizers that provide only nitrogen to plants. This element is essential for vegetative growth, especially leaves and stems. Some examples of commonly used nitrogen fertilizers:
- Urea (46% N) → fertilizer with the highest nitrogen content, dissolves quickly, and is very effective in stimulating green leaf formation.
- Ammonium Nitrate (AN) → contains nitrogen in the form of ammonium and nitrate, making it more readily absorbed by plants.
- Calcium Ammonium Nitrate (CAN) → in addition to nitrogen, also carries calcium, which helps improve soil structure and neutralize acidity.
Functions of Nitrogen Fertilizer:
- Stimulates vegetative growth (stems and leaves).
- Produces vibrant green leaves by increasing chlorophyll levels.
- Accelerates plant development in the early stages of growth.
b. Phosphorus (P) Fertilizers
Phosphorus fertilizer is a single fertilizer that is the primary source of phosphorus (P). This element is essential for root growth, flowering, and seed formation. Examples of commonly used phosphorus fertilizers:
- Triple Superphosphate (TSP) → contains approximately 46% P₂O₅, which is readily available to plants.
- Diammonium Phosphate (DAP) → contains both phosphorus and nitrogen, making it effective in supporting early plant growth.
The functions of phosphorus fertilizer include:
- Stimulating root growth in the early stages of growth.
- Accelerating flowering and fruit ripening.
- Supporting seed formation and crop quality.
c. Potassium (K) Fertilizers
Potassium fertilizer is a single source of potassium (K). This element plays a significant role in fruit quality and plant resilience. Examples of commonly used potassium fertilizers:
- Muriate of Potash (KCl) → the most widely used form of potassium fertilizer, containing approximately 60% K₂O.
- Potassium Sulfate (SOP) → contains both potassium and sulfur, suitable for plants sensitive to chloride (e.g., tobacco, potatoes, or fruits).
The functions of potassium fertilizer include:
- Improving fruit quality, size, and flavor.
- Strengthening plant resistance to drought and disease.
- Strengthening stems to prevent them from falling over.
2. Organic Fertilizers
Organic fertilizers are derived from the remains of living organisms, both animals and plants. They can be compost, manure, green manure, or other organic materials. The advantage of organic fertilizers lies in their ability to improve soil structure and increase the soil's water retention capacity.
Furthermore, these fertilizers can increase soil microbial activity, which plays a vital role in maintaining fertility. The nutrients they contain are generally released slowly, providing a more lasting effect on plant growth. The main functions of organic fertilizers include:
- Providing macro and micro nutrients naturally.
- Increasing soil organic matter content.
- Reducing dependence on chemical fertilizers.
3. Compound Fertilizers
Compound fertilizers contain two or more primary nutrients nitrogen (N), phosphorus (P), kalium (K) in one product. Examples of commonly used compound fertilizer formulas:
- 15-15-15 → 15% N, 15% P₂O₅, 15% K₂O (balanced composition).
- 20-10-10 → 20% N, 10% P₂O₅, 10% K₂O (rich in nitrogen, suitable for the early growth phase).
- 12-12-17-2 → 12% N, 12% P₂O₅, 17% K₂O, and 2% additional elements (usually sulfur or magnesium) for crop quality.
The functions of compound fertilizers include:
- Easier application because all the main nutrients are provided simultaneously.
- Ensures a balanced nutrient balance according to plant needs.
- However, in some cases, the compound fertilizer dose still needs to be supplemented with single fertilizer to meet the specific needs of the plant, especially nitrogen.
4. Slow-Release Fertilizers
These fertilizers are designed to release nutrients gradually, matching the plant’s nutrient needs over time. The functions of slow-release fertilizers include:
- Reduce nutrient loss through leaching or volatilization.
- Ensure nutrient availability for a longer period.
- Suitable for ornamental plants, plantations, and turfgrass.
5. Liquid and Foliar Fertilizers
Liquid fertilizers can be applied directly to the soil or sprayed onto leaves (foliar application).
The functions of liquid fertilizer include:
- Quickly correct micronutrient deficiencies.
- Supply nutrients when roots are unable to absorb them effectively, such as under poor soil conditions.
Why is Fertilizer Lab Testing Necessary?
Each type of fertilizer has different characteristics, advantages, and functions. Selecting the right fertilizer must consider the specific needs of the plant, soil conditions, growth phase, and environmental factors. Effective fertilization not only increases productivity but also maintains soil health and supports sustainable agriculture.
However, all these benefits can only be achieved if the fertilizer used truly matches its nutritional content. Without laboratory testing, there is no guarantee that the fertilizer contains the nutrients as labeled. This risks nutrient deficiencies, soil degradation, and decreased yields.
It is important to understand that fertilizer laboratory testing is conducted at the research and formulation stage, not at the distribution permit stage. The goal is to ensure the fertilizer composition is correct from the start, so that the nutrients are balanced, effectively absorbed by plants, and do not damage the soil.
Untested formulations risk producing less effective fertilizers that can even harm farmers and the environment. Ensure the fertilizer you develop has undergone formulation and nutrient content testing. Conduct laboratory testing from the initial stage to guarantee the quality, effectiveness, and sustainability of the product before proceeding to the distribution permit stage.
Author: Fachry
Editor: Sabilla Reza
References:
Gowariker, V., Krishnamurthy, V. N., Gowariker, S., Dhanorkar, M., & Paranjape, K. (2009). The fertilizer encyclopedia. John Wiley & Sons.
Homenauth, O. (2013). Fertilizer Manual: Concepts, Application, Storage and Handling. National Agricultural Research & Extension Institute.
