Plant fertilizer is often an essential aspect of farming and gardening, especially when farmers want to continually use their soil to grow plants. While plant fertilizer comes in a variety of forms, the plant fertilizer is fundamentally made of many of the same materials. Different types of fertilizers are created in response to different stages of plant growth, different nutrient needs of particular plants and the amount of nutrients found in the soil.
In nature, the natural cycles of plant growth that have evolved over millions of years are disrupted by agriculture and gardening, which attempt to continually grow the same kinds of plants in a given area, thus depleting the soil. According to Penn State, the nutrients that are often recycled through the decomposition of plant material and the return of these materials to the earth also leads to refertilization, but when plants are harvested or disposed of, these nutrients are lost. These lost nutrients are replaced through fertilization.
Soil must be tested to determine what the nutrient balance is in the soil for farmers and gardeners to know how much fertilizer they must incorporate into the soil. Knowing the nutrient composition of the soil can also help farmers know what plants will be the most optimal to grow.
According to Penn State, plant fertilizer is mostly made up of phosphorus, nitrogen and potassium, which are three nutrients that most plants need in order to thrive. Different fertilizers have different amounts of nitrogen, potassium and phosphorus in them. The type of fertilizer bought will be related to the amount of nutrients in the soil and the nutrient needs of the plants that will be grown in a given area. Fertilizer is made up of straight materials, which include anhydrous ammonia, urea, nitrogen solution, triple superphosphate, ammonium phosphates and potassium chloride.
Fertilizer exists in several forms. Granulated fertilizer is produced in a chemical plant and has an even distribution of nitrogen, phosphorus and potassium in each granule, leading to the nutrients being distributed perfectly evenly. This allows plants to absorb an even amount of nutrients. Blended fertilizer, on the other hand, mixes straight materials and sometimes mixes granulated fertilizer with straight materials. While this fertilizer makes it easier for gardeners and farmers to get the right amount of fertilizer to a plant, there is a risk that nutrients might not be evenly distributed and the mixing of urea and diammonium phosphate sometimes creates free ammonium, which prevents seeds from germinating. Fertilizers are sometimes found in fluids in which the fertilizer is dissolved into water or clay is added to prevent fertilizer particles from settling. Fertilizers are also sometimes released as a gas.
According to the Florida Sierra Club, some fertilizer runs off into water supplies, where this fertilizer can cause algae blooms. This is a result of the nutrients in the fertilizer feeding the algae. These blooms can be toxic to those who are exposed to the blooms and can also poison fish.