The Effect of Plant Hormones on Barley Height in Unfavorable Soil Profiles

     My experiment focuses on the use of auxins, specifically indole 3 butyric acid, to help barley yield in unfavorable soil profiles. First, I studied phototropism, which is the orientation of a plant towards light so it can capture solar energy (2). It was actually Darwin who propsed that the "circumnation associated with plant growth could be directed by a stimulus such as light" (2). The sunlight aquired by plants are used in photosynthesis, which helps create ATP, regulate enyzme activity, and continue many other biological processes (1). Basically, plant growth hormones like indole 3 butyric acid stimulate cell elongation, root initiation, and vascular differentiation (3). Since phototropism and growth hormones support root growth and plant growth, I wanted to apply that concept to see if indole 3 butyric acid could help increase the yield of barley.

     First, I decided to research indole 3 butyric acid. Indole 3 butyric acid is a type of auxin that induces root growth better than similar auxins, like Indole 3 acetic acid, and its more stable over longer periods of time (8). It also promotes root growth in most plants and crops over a longer period of time because it's not as readily subject to oxidation (9). It's also indigenous to plants and is naturally found within their bodies. That's how I decided Indole 3 butyric acid was a good growth hormone to try to get barley yield to increase in the following three unfavorable soil profiles.

     The soil profiles vary based on the three countries I picked with very low annual food production. First, Haiti's poor farming practices were brought around by disregard for the environment, taking natural resources at a faster rate than they could replenish themselves. Haitian soil, as a consequence, has degraded over a vast amount of time due to intensive monocropping, deforestation, and soil erosion, which make it hard for crops to grow (4). Simply, it's formed by a high concentration of silty clays. This differs greatly from the Kenyan soil profile. Kenyan soil also contains a clay base but lacks organic matter and nutrients. Also, based on geographic location, Kenya has a rocky soil profile made up of sedimentary rocks, which make it hard for plants to grow (5). Lastly, the Australian soil profile doesn't have a clay base like the other 2. Australian soil is very sandy which allows lots of water and fertilizers to fall through the loosely packed molecule (7). This leads to low soil fertility and the loss of nutrients like the Kenyan soil (6). Based on this research, I created my hypothesis.