What is fertilizer?
Every bag of fertilizer has a set of numbers called N – P – K; Nitrogen – Phosphorus – Potassium (Potash). The numbers represents the percent of that macro-nutrient in that particular bag of fertilizer. These nutrients are essential to plant health. Some bags of fertilizer may also contain micro-nutrients and/or pesticides. The type of fertilizer, weather, and the actual property all play a role in timing of an application in order to keep grass attractive and resilient.
Too much fertilizer or too little, both can be detrimental for a lawn. You want to decide on the right fertilizer, at the right time of year in order to be efficient and most beneficial. Temperatures will effect which nutrients to use and choice on how slow the fertilizer releases nutrients. The way fertilizer is coated effects the release of nutrients, dictating how long fertilizer will stay in the soil. Applying a quick release fertilizer in the summer could be risky and could destory a lawn.
Fertilizer can stay in the soil anywhere from 4-6 weeks, but rain/water will cause nutrients to leach faster. This is one reason why over-watering can be bad.
The minimum, by law, is 20% slow release fertilizer. Other laws in New Jersey are limitations on phosphorus, only being allowed to apply it with seed or soil test results show a deficiency. Only 1 pound of nitrogen can be applied at once per 1,000 square feet. New Jersey law even states that fertilizer can only be applied between March 1st and December 1st. These laws were put in place to prevent algae from forming in our waterways, influencing the ecosystem. Keeping our waterways clean is very important to us. Dirt & Turf has the knowledge and respect required to help keep our environment safe.
How do nutrients help my lawn?
Nitrogen promotes plant growth. Nitrogen is part of every protein in the plant, which is part of every process, from growing new leaves to defending against pests. Nitrogen is also part of the chlorophyll molecule that is involved in creating food through photosynthesis, giving plants their green color. Older grass tends to have less mobility of resources within the plant. This could lead to more yellowing at the end of the season, before dormancy, when grass reaches a certain age.
Phosphorus promotes new growth and root growth. Root development leads to winter hardiness and improves the defense against other environmental stresses, including disease. Phosphorus is required for establishing roots, seed development, cell division, and the synthesis process used by plants. Phosphorus is not very mobile in soils, so it doesn’t have to be applied regularly.
Potassium is what keeps our grass strong. This nutrient is involved in cellular metabolism, environmental stress resistance, disease resilience, internal water management, and wear tolerance. It reduces transpiration, so grass needs less water. Potassium also stimulates plant enzymes used in protein, sugar, and starch synthesis. Being deficient in potassium could lead to permanent injury from drought, winter, traffic and/or disease.
Why is soil pH so important?
Soil pH is the most important factor in growing grass since it affects the availability of nutrients in the soil that are essential for plant growth. The optimum soil pH range for grass is 6 – 6.6 on the pH scale. Depending on how acidic the soil is, grass may not even be receiving nutrients from the fertilizer. Why even waste money on fertilizer if you have acidic soil, which may not be a quick fix. This is why having the soil tested is extremely important. Once at optimum level; the next time you seed you will have better results, grass will thrive and be more durable. Even weed controls will work better!
If your soil is too acidic, lime is recommended. Sometimes multiple applications are recommended when the soil is very acidic. Please keep in mind, each lime application may take 6 months to fully correct the soil pH and 50 pounds per 1,000 square feet is the most that can go down at one time without wasting. When multiple applications of lime are needed, they would have to be spaced out 6 months apart to efficiently correct the soil pH. Lime can be done anytime of the year and will not burn grass if incorrectly applied. Can you apply too much lime? Yes, if the soil was already neutral or alkaline and lime was applied on a regular basis, this would raise the pH too high past the recommended range. Over applying one application of lime would just waste money. It is recommended to have soil tested every other year.
Nutrients included in lime:
Calcium will not nuetralize the soil pH, but often is needed when soil pH is too low. Calcium plays a major role in the physiology of grass, strengthening its physical structure, increasing nutrient uptake and protecting grass from disease.
If magnesium is needed, dolomitic limestone would be applied instead of your usual calcitic lime. Dolomitic lime contains calcium, but higher levels of Magnesium. Magnesium is a carrier of phosphorus in plants, regulates the absorption of calcium and plays a major role in photosynthesis.
Would my neighbor have a similar soil analysis?
Adjacent properties may have similar results on a soil test, but many instances soil requirements are different between neighbors. Just about every property is different. Here are some factors that could make one property different from another:
- It depends on what kind of plants and trees are on the property. Oak trees and evergreen trees/shrubs will tend to make the soil acidic.
- What a homeowner or the previous owner applied on the property throughout the years will play a huge role. Topsoil could even effect nutrient levels and soil pH.
- Not only will fertilizer effect nutrient levels in the soil, fertilizer has a small amount of sulfur, which could make the soil acidic. Years of neglect could cause issues.
- The way a property is designed, or sloped, leading to runoff of nutrients or lower the pH. Rain water is acidic.
- Irrigation (over watering) could lead to leaching of nutrients.
- Construction may make the soil acidic as well. Soil a foot or more down that is disturbed and exposed to oxygen can lead to a reaction with elements within the soil, causing soil to become acidic. A new house being built, a pool being installed, or any kind of excavating are examples of how the soil can be introduced to oxygen for the 1st time.
Find out more about soil testing, please visit Rutgers Soil Testing Laboratory.