New Fertilizer Product for Vegetables

¶ … New Fertilizer Product for Vegetables Identify the components Fertilizer (New) (new fertilizer product) Fertilizer (Std) (standard fertilizer product) plots in community gardens across the city Cucumber, green pepper, and broccoli plants Gardening journal Scale What is the research question? This research analyzes whether adding a new fertilizer product (Fertilizer (New)) to the soil will produce a higher total vegetable yield, in grams, when compared to: 1) vegetables grown in soil free of commercial fertilizers, or 2) vegetables grown in soil treated with the industry standard fertilizer product (Fertilizer (Std)).

What is your hypothesis? Total vegetable yield will be significantly higher in soil treated with Fertilizer (New), compared to vegetable yields from soil treated with Fertilizer (Std) or from commercially untreated soil. How would you select your subjects and assign them to a group? Volunteers from 30 community gardens across the city will be recruited to plant vegetable gardens consisting of a fixed number of cucumber, green pepper, and broccoli plants.

After recruitment of volunteers, each will be randomly assigned a soil treatment modality (Fertilizer (New), Fertilizer (Std), or no commercial fertilizer). Treatments will be equally assigned across groups (10 plots per treatment). How would you conduct the experiment? Describe your procedures. On day 1, each volunteer will receive an equal number of vegetable plants and the soil treatment assigned. Volunteers will then prepare their soil, plant the vegetables in their community plots, and be responsible for maintaining their gardens for a total of 20 weeks.

Participants must keep a gardening journal outlining their observations and care schedule (watering, weeding, etc.), and submit weekly reports. When vegetables are ready to harvest, participants will weigh the vegetables right after picking (gram scales provided) and note totals in their weekly report. At the end of the 20-week study period, total weights will be tabulated and compared across treatments (fertilizer type). Analysis will also consider whether type of vegetable impacts results.

Journals will be examined for gardening care and experience, and results may be re-analyzed to exclude outliers or other unexpected events. What are the limitations to your experiment? Vegetable yield can vary by a number of factors, of which fertilizer type is only one. The randomization of treatment type should minimize underlying differences between intervening variables such as volunteer efficacy, initial plant condition, initial soil condition, etc. Moreover, the analysis of results will use the weekly journals in order to control for outside factors.

Still, we should use caution when attempting to generalize results from a limited sample over a single growing season. This research design also relies heavily on self-reporting from participants. Thus, results are subject to measurement error and reporting bias. Again, the randomization of fertilizer.