Tuesday, November 14, 2006

Simple and Powerful laboratory Exercises in Turfgrass Nutrition.

Ingrid Hersh, Maxim Schlossberg, and Philip Cook. Penn State University, 116 Asi Bldg, 116 Asi Bldg, University Park, PA 16802, United States of America


The process of developing a 15-week semester schedule of purposeful laboratory activities to complement an upper-division applied science course can be an act of trial and error when first implemented.  In the offering of Turfgrass Nutrition (TURF 435), the process began with idealistic brainstorming, continued with intensive effort fraught with unforeseen difficulties, and ended with less success than originally expected.  After two of these lackluster yet enlightening cycles, experience and perseverance have joined to facilitate development of three laboratory exercises that embrace the scientific method while demonstrating important agronomic fundamentals with remarkable repeatability.  These lab exercises used in resident instruction of TURF 435 are: a 9-week nitrogen fertilizer-release study, an N x P fertilizer and Lolium perenne L. establishment experiment, and a demonstration of cation-uptake-induced rhizosphere acidification.  The N fertilizer-release exercise requires significant initial preparation, yet can be easily maintained for repeated use thereafter.  The Lolium perenne L. establishment exercise requires a three week period, however it is inexpensive, easily prepared, and clearly and concisely demonstrates the benefits in soil fertility optimization when fostering turfgrass seedling growth.  Afterwards, a follow-up experiment utilizes the established ryegrasses, indicator dye, and agar to vividly qualify cation-uptake-induced soil pH change in the turfgrass rhizosphere.  All materials and methods used to conduct the mentioned laboratory exercises in turfgrass/plant nutrition will be provided and discussed.  An annually-updated TURF 435 laboratory component will maximize experimental repeatability, concept applicability, and positive student opinion; while minimizing cost of implementation. 

Handout (.pdf format, 2159.0 kb)