Plant Growth on a Gravel Soil: Greenhouse Studies

摘要

Two greenhouse studies were performed with gravel soils to determine the requirements for nitrogen (N), phosphous (P), and potassium (K) for grass establishment and to assess the establishment performance of 15 types of grasses. The fertilizer study consisted of 30 treatments, each representing a different combination of application rates of N, P and K. A seed mixture containing 'Nugget' Kentucky bluegrass, 'Pennlawn' red fescue, and annual ryegrass was sown, and the plants were harvested 133 days after sowing. Plant leaf and root weights were measured, and soil samples were analyzed for pH,P,K and soluble salts. In the grass study, 15 grasses for 76 days. All treatments were fertilized at the beginning on the study. Plant establishment was periodically assessed and yields were measured at the end of the study. In the fertilizer was periodically assessed ans yields were measured at the end of the study. In the fertilizer study, N and P were shown to be limiting to leaf growth on this soil. Applications of P were the most beneficial for root growth. Needs for K were less evident, but it was required for maximum leaf growth at the higher application rates of N and P. The greatest yields were recorded when all three elements were applied, while at the lower application rates only N and P were required to promote growth. Plant leaf growth was closely correlated with root growth. Soil pH decreased with increased rates of fertilizer. In the grass study, three tall fescue varieties and two ryegrasses established themselves more rapidly than the other grasses. Reubens Kentucky bluegrass, FL 1 hard fescue, Pennlawn red fescue, the tall fescues, and the ryegrasses were the best yielders. (Author)