Abstract:
In this experiment, 2% milk was used to observe it's effect on the growth of Rye Grass seeds. For approximately two weeks the seeds were watered and "milked" in soil while their height was recorded. At the termination of the experiment, the experimental hypothesis of the milk causing the plants to grow more overall, proved accurate.
The experiment was conducted to see if giving rye grass seeds 2% milk over water would increase their growth. The dependent variable was the plant height. The independent variables were the water and the 2% milk. The experimental hypothesis was thought to be that, when given milk over water, rye grass seeds would have an overall faster growth rate than the seeds given only water. It was thought that the seeds might receive more nutrients from the milk than the water.
Subjects: Two groups of "Annual Rye" grass seeds were planted. Thirty seeds were used in the control group and thirty were used in the experimental group. All sixty sprouted.
Apparatus: The soil used in this experiment was Hyponex All Purpose Potting Soil. The main ingredients included Hypnumpete Forest Products/Compost and Perlite Sand. The variety of grass seeds was of a Fall Green Grass Seed Mixture, Wonderlawn, Inc., Buffalo, N.Y. The mixture consisted of 37% Barverdi Rye, 32% Annual Rye, 8% Red Fescue, 8% Pinnacle Perennial Rye, and 5% Kentucky Bluegrass. The rest of the materials used include: 2 plastic bags, one large box with divider, lamp (60 W bulb), water, and 2% milk.
Procedure: All sixty seeds were planted on the same day in the same potting soil. For the first four days, both the control and the experimental group were watered and kept in plastic bags to ensure humidity for maximum growth. After noticeable grasslings sprouted, the plastic bags were removed. Holes were also punched in the bottoms of both boxes to allow water drainage. The seeds were fed and given ample light to allow for maximum growth. On the fifteenth day of the experiment, both groups of seeds were dug up, measured, and recorded. The results and observations were logged in a daily journal and were graphed (see figure 1).
The Mann-Whitney U test was used to analyze the data. The results are as follows:
N1= 30 R1= 910 (avg.rank 30.3) U1= 455 (obtained)
N2= 30 R2= 920 (avg.rank 30.6) U2= 445
The larger U was used as the obtained value because the average ranks for R1 were smaller than the average ranks of R2.
To find the Critical U, a Z score was used because the sample size was larger than 20. From the Z score, we use the C column on the table to determine whether to reject or fail to reject the null hypothesis. The results are as follows:
Z = 0.074
Area in C column = .2296
X fail to reject the null hypothesis
The experimental hypothesis was that 2% milk would aid in the growth of Rye Grass seeds. The null hypothesis stated that the 2% milk would have no effect on the plant growth. According to the statistics used to analyze the data, we should fail to reject the null hypothesis. We fail to reject the null hypothesis because our obtained results for U are not equal to or less than .05. Rather, the value for the obtained U is much larger than the value for the critical U. Since we fail to reject this statement, our experimental hypothesis does not entirely hold true. Therefore, the application of 2% milk on Rye Grass seeds does not aid in their growth.