nvestigation, I will be exploring the effect of vermiculite concentration within the substrate as it relates to seed germination, seedling growth, and survival. Vermiculite is a natural compound of the chemical formula (Mg,Fe++,Al)3(Al,Si)4O10(OH)2•4(H2O), and is mined across the United States and the rest of the world (Barthelmy, n.d.) Horticultural vermiculite is commonly used in agriculture, as it improves soil aeration while retaining necessary moisture and nutrients for plant growth (Horticultural Uses, n.d.). Vermiculite is particularly effective in seed germination, as it increases the availability of oxygen and water, two necessary components to germination, increasing germination rates when it is utilized (Horticultural uses, n.d.)

The relationship between vermiculite and seed growth has been previously investigated in some species. A 2015 study found that when Plukenetia volubilis L. seeds were grown either sand or vermiculite, the seedlings in vermiculite had a 98% survival rate, while while the survival rate of seedlings grown in sand was only 79%. (Cardoso, Obolari, Borges, Silva, & Rodrigues, 2015).

In my exploration, I will study the effect of vermiculite on Phaseolus vulgaris germination and seedling growth. Phaseolus Vulgaris, commonly known as a french bean, best grows in a sunny, warm position, in light, well drained soil, and prefers a ph between 5.5 and 6.5 (Phaseolus Vulgaris, n.d.).

Hypothesis/Explanation

Increasing the concentration of vermiculite within the substrate will increase germination rate and seedling survival, but only until a certain point, at which the substrate will lack the necessary nutrients for plant growth normally supplied by soil, in turn decreasing seedling survival. This is because vermiculite increases aeration of the soil while also retaining water. Water retention is essential to germination and seedling development, as germinati