Introduction
It has been noted that after spreading salt daily on the driveway to melt snow during the winter; during spring time, the growth of grass is affected. It is noted that when grass begin to grow in spring time, there may be no grass growing for about three inches from the driveway or the grass next to the driveway may grow at a slow rate. Salt is known to have disastrous effects on vegetation, including grass. The practice results in an increase in concentration of salt in the soil and/or accumulation of salt on the foliage. Grass affected by high salt concentration shows symptoms like browning of foliage or complete death. High concentration of salt particles, such as sodium and chloride, accumulates in the plant tissues resulting in osmotic stress and eventual dehydration of plant tissues. Sodium is also responsible for interfering with soil permeability thereby inhibiting plant growth (Zehra & Khan, 2007).
Hypothesis
Road salt inhibits the growth of grass.
Prediction
If road salt is not applied to the grass, then the grass is expected to have normal growth.
Materials
- grass
- water
- soil
- seedling trays
- road salt
Constants
- Type of grass
- Type of soil
- Source of water
- Temperature
- Dew point
- Type of road salt
Independent Variables
- Road salt added to the grass is the only independent variable.
Dependent variables
- Grass growth
Control
- No application of road salt on the grass
Experimental procedure:
- Put equal amounts of soil on the seedling trays and label them, A and B. Plant the grass seedlings on the soil placed on the seedling trays.
- Water the newly planted grass with equal amounts of water and maintain constant temperatures and dew point around the two seedling trays.
- Observe the performance of the grass as it grows over a span of two weeks
- Divide the 14-day seedlings in each seedling tray into four distinct groups and label them as Q, P, R and S, in seedling tray A and E, F, G and H in seedling tray B; each with 20 grass seedlings ensuring that they are of the same height.
- From seedling tray labelled A, put road salt onto each group in the ratio of 0.5:1:1.5:2 (g) on the tenth day.
- Leave the seedling tray labelled B with no road salt application.
- Observe and record the change in grass height over the next 15 days.
- The grass height is to be measured using a rule after every five days.
- This data will be entered in different data sheets and a comparison done after the 15 days (Easton & McColl, n.d)
Results
The results obtained from the experiment were recorded as shown in the table below:
Conclusion
From the results obtained, it is clear that road salt has a negative impact on the growth of grass. The experiment also shows that the higher the amount of salt, the more the inhibition on the growth of grass. By measuring the height of the grass while holding other factors constant, the effect of salt has been clearly brought out. This supports my hypothesis that ‘road salt inhibits growth of grass’. This shows that loss of vegetation that has been witnessed in many parts of the world where road salt is applied can be attributed to this salt.
References
Easton, V.J. & McColl, J. H. (n.d). Experimentation. Web.
Zehra, A & Khan, M. A. (2007). Comparative effect of Nacl and sea salt on Germination of halophytic grass phragmites Karka at different temperature regimes. Pak. J. Bot., 39(5), pp. 1681-1694.