Nitrogen Cycle Ninja, A Teaching Exercise.

Long-term student retention and understanding of information is the goal of virtually all teachers/instructors/professors. One exercise was evaluated for its effectiveness to improve student retention of the nitrogen (N) cycle. This was conducted within a 3-h course entitled Soil-Plant Relationships that had a mix of M.S. and Ph.D, students. The N cycle was thoroughly discussed in class and students had prior knowledge that this information could be requested on unannounced quizzes. One week after this was discussed, an unannounced quiz was given and students were asked to provide a complete graphic N cycle. Prior to handing out the quiz, they were informed that proper completion of this material would qualify them as a Nitrogen Cycle Ninja (def: 1: individual with constant awareness and understanding of N dynamics, 2: warrior, perpetually ready for battle, and pursuing truth of all concepts as they relate to N in soil-plant systems) and they would receive a card that authenticated that achievement. Also, once this information was adequately learned, they could use their card (which had a miniature N cycle and list of all components) on all subsequent exams. Non Ninja card holders would not benefit from this privilege. Ninja status could only be achieved on unannounced quizzes, a sign of constant awareness and understanding of N dynamics. On the first quiz, only two students received their Ninja card. By the second pop quiz on the N cycle (given 14 d later), 16 of 17 students were certified Nitrogen Cycle Ninjas. An anonymous postclass student survey found that most students were pleased with the exercise. Three Dep. of Agronomy, Oklahoma State Univ., Stillwater, OK 74078. Contribution from the Oklahoma Agric. Exp. Stn. Received 16 Aug. 1996. 'Corresponding author (wrr@soilwater.agr.okstate.edu). Published in J. Nat. Resour. Life Sci. Educ. 26:39-42 (1997). months after the final exam, 11 students were given impromptu visits and asked to provide the complete graphic N cycle, in addition to all components discussed in class. Six of the 11 students that were retested would have retained their Ninja cards. Students commented that similar approaches could be used for other subject materials. Also, most students noted that the exercise was fun, which increased their motivation to learn. npHOROUGH UNDERSTANDING of the N cycle provides releA vant and useful information to professionals in academic, private, and public sectors. Failure to understand one or more components of the N cycle can lead to misinterpretation of information as it relates to fate of mineral and organic N fertilizers. For graduate students in soil and crop sciences, retention of the information included in N cycling in plants and soils is critical, since N is the most limiting nutrient for crop production worldwide. Methods of improving retention of information have been evaluated in virtually all scientific fields. Recent work has focused on the differences associated with problem solving approaches vs. subject matter approaches. Flowers and Osborne (1988) noted that the problem solving approach is no more or less effective than the subject matter approach as measured by student achievement, regardless of the cognitive level of the questions. However, they further noted that for high level cognitive items, the problem solving approach resulted in lower achievement loss. More recent work by Boone (1990) indicated that the problem solving approach to teaching increased the level of student retention of agricultural knowledge. This approach offered the opportunity to solve real problems as a part of their classroom instructions. J. Nat. Resour. Life Sci. Educ., Vol. 26, no. 1, 1997 • 39 Table I. Outline used to comprehensively address the N cycle for graduate students in soil and crop sciences. 1. Organic matter Addition Symbiotic fixation Nonsymbiotic fixation Fertilizer Organic Inorganic Removal II. Volatilization (fertilizer addition) Ill. Mineralization Amiaization Ammonification Fixation (exchange) Nitrification IV. Immobilization V. Denitdfication VI. Gaseous Plant N Loss VII. Leaching VIII. Oxidation states of N IX. C/N ratio of the organic matter X. Soil-plant inorganic N buffering Long-term student retention and understanding of information is the goal of virtually all teachers/instructors/professors. However, measuring long-term retention is difficult since students leave and are seldom revisited in a setting where this can be evaluated. Holcomb et al. 0982) suggested that a 6-mo time interval represented a long-term retention measure. While 6 mo is better than 7 d, most instructors would like to see retention approach years. The present study was stimulated by a presentation from James (1995) in which innovative methods of teaching (use of poetry in science) were discussed. The objectives of this exercise were: (i) to improve retention of N cycle information via a combined peer pressure-status approach that was expected to increase participation (Nitrogen Cycle Ninja member) and (ii) to assess student response related to this activity. MATERIALS AND METHODS One competitive peer pressure-status exercise was evaluated to improve student retention of the N cycle. This exercise was conducted within a 3-h course entitled Soil-Plant Relationships that is taught primarily to M.S. and Ph.D. students in soil, crop, and range sciences. Five, 50-min lectures were used to completely discuss the N cycle. Prior to this, three lectures addressed the composition of organic matter, carbon (C)/N ratios of different organic materials, a brief overview of the C cycle, factors affecting the decomposition of organic matter, and microbial action on organic matter. Once this was complete, the N cycle was discussed in what was considered to be a logical sequence (Table 1). Supplemental text information concerning the N cycle was derived from Alexander (1977) (chapters 15-19). Work Raun and Johnson (1995) and Johnson and Raun 0995) used for detailed discussion of N-cycle components related to soil-plant inorganic N buffering. Once this was complete, students were informed that a pop-quiz would be given in which they would be asked to provide a detailed sketch of the N cycle. From class, an improved version (previously developed in this class) of the N cycle was distributed to all students that included the influence of temperature, moisture, oxidation, and reduction on N transformations (Fig. 1). One week after this was discussed, an unannounced quiz was given and students were asked to provide a comprehensive diagram of the N cycle. Prior to handing out the quiz, they were informed that proper completion of this material would qualify them as a Pseudomonas, Bacillus, Thlobacillus Denl~tflcans and T. thiopar~s NO~" Key Oxidation Reactions Reduction Reactions Organisms Fig. 1. Graphic representation of the complete N cycle that was distributed to students involved in the Nitrogen Cycle Ninja exercise. 40 d. Nat. Resour. Life ScL Educ., VoL 26, no. 1, 1997 Nitrogen Cycle Ninja and that they would be given a card that authenticated that achievement. The card included their name, a miniature N cycle on the front and a list of all components that needed to be addressed for Ninja status on the back (Fig. 2). The card was laminated and printed in color, following adequate attention devoted to finding an appealing design. Once all required N cycle information was adequately learned, they could use their card on all subsequent quizzes and hour exams. Non Ninja card holders would have to continue answering the N-cycle test question from memory alone. Ninja status could only be achieved on unannounced quizzes, a sign of constant awareness and understanding of N dynamics. Each student was expected to be a warrior, perpetually ready for battle and pursuing truth of all concepts as they related to N in soil-plant systems. Nitrogen Cycle Ninja