Gardening, landscaping, lawn care—no matter what form of yard work you do, and no matter how large or small the scale, chances are you’ve been introduced to the idea of using fertilizer. Every garden center is filled with products touting their ability to provide you with bigger and better produce, a lusher and greener lawn, or fuller, more attractive shrubbery. Nature, it seems, needs a helping hand to succeed. Before you grab whatever bag of fertilizer is on sale, however, it helps to have a basic understanding of the fundamentals of fertilizer and why your plants respond so well to its use.
What Is Fertilizer?
At its most basic, fertilizer is plant food. Using a combination of potassium, nitrogen, and phosphorus, fertilizer provides plants with what they need to grow. During its life, a plant absorbs nutrients from the soil and uses them to produce crops, flowers, or fuller plants. When the crops are harvested, the soil no longer has nutrients available for the next set of plants. Fertilizer helps replenish the nutrients used and prepares the soil to grow again. Particularly in commercial applications, the high-yield demand for crops does not allow the soil enough time to naturally replenish itself, thus creating the need for fertilizers.
The elements used in fertilizer are found in nature. Potassium is abundant in the earth’s crust. Rain, erosion, and other natural processes filter it into the earth’s water supply. After evaporation, mineral deposits, including potassium, are left behind. The potassium used in fertilizer is harvested from these deposits. Nitrogen, part of the earth’s atmosphere, combines with natural gas into a form that can be processed by plants. Phosphorus is harvested from rock deposits that contain fossilized marine life. The harvested material is processed to form water-soluble compounds for plant use.
Why Are There So Many Different Types?
Fertilizer is labeled according to the percentage of nutrients it contains, with three numbers identifying the amount. Nutrients are always listed in the same order: nitrogen, phosphorus, potassium. Therefore, a bag of 10-0- 5 contains 10 percent nitrogen, 0 percent phosphorus, and 5 percent potassium.
Each nutrient has a different role in soil, and you should choose your fertilizer based on the needs of your particular plant and soil. Several multi-purpose fertilizers are designed to meet a broad range of needs and can be used at particular times of the year. Spring mixes, or starter mixes, contain extra phosphorus to stimulate root growth for new plants. Fall mixes are used to repair soil after summer damage and build stronger roots for the upcoming winter.
To ensure that you buy the fertilizer your soil needs, it is helpful to have your soil tested—either by a professional or by using a soil testing kit (available at most garden centers). By understanding the unique needs of your soil, you can be confident that you are applying exactly what your plants need to grow. Soil testing also prevents over-fertilizing and is a more efficient way to manage fertilizer use.
Why Do Your Plants Need It?
Each element of fertilizer is used by plants for different functions. Nitrogen is used to boost growth and stimulate a dark, green color in plants. Phosphorus stimulates new growth in the roots and is used to feed seedlings. Potassium increases vigor and health while preventing disease and reducing stress. Each of these elements is instrumental to increased production at various points in your plant’s life cycle. When used correctly, fertilizer not only increases crop yield, but it provides environmental protections by providing healthy, green spaces that filter water supplies, provide oxygen, reduce water run-off, and give people a safe space to enjoy. By providing your plants with the right fertilizer, you are giving your plants exactly what they need to grow.
While the elements included in fertilizer are found in nature, it would be impossible for soil to be replenished after every harvest. Soil is replenished by the decay of plants and animal manure; however, it can take decades for the soil to be returned to its rightful state. Today’s agricultural climate does not allow for decade-long periods of rest between growing cycles, forcing farmers to produce more food in a smaller amount of land. Using fertilizer to boost soil is essential to maintain the current food supply.
Modern fertilizers have come a long way from the broad-use fertilizers of the past. As farming practices have improved, soil testing, need-specific fertilizers, and precise applications have reduced environmental impacts and increased crop yield and results. Farmers today produce nearly three times the amount of crops on the same amount of fields as they did fifty years ago, thanks to the new advances in fertilizers. As farmers adopt the use of new fertilizers, plants are more equipped to withstand harsh weather and disease and are able to maintain soil moisture, preventing some of the food-related disasters of the past. Fertilizers are quickly becoming a plant’s best resource for success.