Salt and Grass Growth
In the winter, salt is spread daily on the driveway in order to melt snow and ice. In the spring, when the grass begins to grow, it is noticed that there is not any grass growing about 3 inches from the driveway. In addition, the grass appears to be growing slower about 1 foot from the driveway. Prior to an experiment being conducted, it must be determined what the salt compound being applied to the driveway is made up of in order to get a clear picture of how it may be affecting the grass growth. Salt is sodium chloride that occurs naturally on earth as mineral halite. When mineral halite evaporates, it turns into salt lakes. The chemical compound is NaCl with 60.663% elemental chlorine (Cl) and 39.337% sodium (Na). Salt crystals are cubic in form and can be modified by temperature. Salt that is commonly used for deicing is rock salt also known as halite. Rock salts crystals are much larger than the common table salts crystals (What is salt?, 2013).
Based on the giving facts and the chemical makeup of salt, it is believed that the salt compound used to melt the ice and snow is effecting the growth of the grass around the driveway and along the edges of the lawn.
Evidence obtained from the experiment, if the hypothesis is correct, will indicated that grassy areas nearest to the driveway that are exposed to salt does not grow and the grassy areas less exposed to salt will grow slower than areas that are not exposed to salt at all.
Controlled Experiment Methods:
One square foot of sod that stands at 3 tall, three planters that are 2 x 6, rock salt, three one cup measuring cups have been obtained. The sod will be cut into three 4 strips and placed into each planter. Each planter will be labeled as Planter #1, Planter #2 and Planter #3. Planter #1 will not have any salt content added to the water and will be given one cup (8oz) of water daily for three months. Planter #2 will be watered with a solution mixture of one teaspoon of rock salt dissolved in one cup of water daily for three months. Planter #3 will be watered with a solution mixture of two teaspoons of rock salt dissolved in one cup of water daily for three months. These test planters will be outside during the cold weather for three months. After three months and warmer weather has arrived, the planters will be given only tap water without any salt solution for three months. This will allow the soil the grass is in to absorb the salt solution and give amble amount of time to react to the solution and the results will be evident in spring.
After three months of watering the planter in cold weather with a salt solution and then three months of watering the planters with tap water, the results were as expected. Planter #1 that was watered only utilizing plain tap water was dark green and grew to be 12 tall which is a 9 growth from its original state. Planter #2 that was watered with the one teaspoon salt rock solution was a lighter green with some yellowing and only grew to be 6 tall which is only a 3 growth from its original state. Planter #3 that was watered with the two teaspoon salt rock solution died and there was not any growth regenerated.
With the given results of this experiment, the hypothesis is acceptable and was substantiated. The results that were obtained in this experiment will assist in planning another method for deicing the driveway during the winter in order to ensure the grass around the driveway will grow the following spring. Due to the amounts of salt currently in the soil, it may take some time to deplete the levels in order for grass to begin growing in those saturated areas again. Depleting the levels of salt may require nutrient rich soil to be brought in and replace the sodium chloride saturated soil. In addition, a barrier will need to be set in place to give separation from the runoff of the driveway during the winter time. The barrier could direct the overflow of the salt solution to run off into the street which would also help the ice and snow on the roadway to be dissolved without additional efforts. This will alleviate such great salt saturations into the soil around the driveway; thus enabling the grass to grow in those areas.