The effect of Nitrogen based fertilizer on the growth of Saintpaulia Ionantha

Brandy Marshall

Undergraduate – Health Sciences

Tennessee Technological University

Cookeville, TN 38505

25 October 2006

Project Summary_________________________________________________________3

Key Words _____________________________________________________________3

Introduction_____________________________________________________________3

Methods and Materials____________________________________________________5

Expected Results and Benefits______________________________________________7

Personnel ______________________________________________________________7

Ethics Statement_________________________________________________________7

Project Timeline_________________________________________________________7

Literature Cited _________________________________________________________8

Budget ________________________________________________________________9

            People are often torn over whether or not to spend the extra money on fertilizers whether it be for their gardens or large field crops. They often wonder if the fertilizers will actually make the plants larger, so the problem this experiment explores is do fertilizers really work?  The object of the experiment is to show the effect nitrogen fertilizer. This will be done by testing 6 African Violet plants, watering three with water only and the other three with a nitrogen fertilizer mixture. At set times, plant height, number of leaves and number of flowers for each plant will be recorded. At the end of the experiment, these values will be used to compare fertilizer and non fertilizer growth.

 It is hypothesized that the plants given the fertilizer mixture will grow larger than those only given water. If what is expected occurs, fertilizers can be said to be beneficial in that the fertilizer helps plants to grow larger in a shorter amount of time.

Saintpaulia Ionantha, African Violet, fertilizer, Nitrate, Ammonium, Nitrogen

            As we all know, the world population grows everyday, and everyday more and more emphasis is being placed money. Fertilizers of any sort can become very expensive, especially nitrogen based ones. That is one of the reasons people today ask if fertilizer really works or not. To the average person who just fertilizes their flower garden, cost usually is not a major concern. These people only want their flowers to grow large and beautiful. On the other hand, to people who own farms or nurseries and depend on the plants for a living, cost is a major concern.  

            For this experiment, nitrogen fertilizer will be the fertilizer tested. Nitrogen can be given to plants in many different forms including organic fertilizer (animal manure, composts, or plant residues), NH4+ and NO3 ˉ (Heeb 2005). The fertilizer used for this experiment is 24% Nitrogen, containing 3.5% ammoniacal nitrogen and 20.5% urea nitrogen. Many experiments been conducted to test the effects of nitrogen based fertilizers and conclude that plants given nitrogen fertilizer will grow larger and faster than the same type of plant not given fertilizer. One, for example, tested the growth rate of flowers based on number of times a fertilizer was given and whether or not the plants were in sunlight. It was concluded that the plants given the most fertilizer, grew the largest in sun and shade (Stafne et al, 2005).

One problem with fertilizer though is that it only stays in the soil for a few days, then has to be reapplied. Urea’s half life, for example, is only about 6 days immediately following transplanting and then falls to only 3 days (Sheehy, 2005). This fact once again raises the question, are fertilizers worth the extra money?

There have also been a few studies recently concerning the safety of using nitrogen based fertilizers. Many times when the nitrogen is in the nitrate form, the crop is unable utilize the entire amount of fertilizer it is given. This leaves the remaining nitrogen to run with water from the soil into groundwater systems or drainage systems (Jiusheng et al, 2005).

The objective of the experiment is to show effects of nitrogen based fertilizers in hopes of answering the question do fertilizers really work. If the null hypothesis is correct, plants given the fertilizer mixture will not grow larger than plants given no fertilizer. If the hypothesis is correct, plants given fertilizer will grow larger than the plants not given fertilizer and it could be said that yes, fertilizers do work and are worth purchasing.

             Materials for this experiment are all easily acquired. The materials include 6 plants, 6 pots, potting soil, nitrogen fertilizer (Miracle grow for house plants was used in this experiment), water and a plastic container for the fertilizer mixture. 

            To begin this experiment, one must first acquire all materials needed. Then, measure equal amounts of potting soil into each of the six pots. Moisten the soil with equal amounts of water, and label 3 pots with “fertilizer” (the treatment group) and three pots with “no fertilizer” (the control group). Now, plant one plant in each of the pots and place near a sunny window. Check plants regularly and water when soil gets dry. Record the observations in a notebook once a week. Observations should include stem height, number of leaves and number of flowers (see Table 1).

The experiment is being conducted in my apartment, where the plants have access to sunlight and I have easy access to the plants for observations and watering. At the end of the experiment, the values recorded will simply be used to compare the sets of plants and determine which set grew the most. A graph or table will then be constructed using Microsoft Excel of the comparison.

The method used for this experiment was found at: http://www.sciencebuddies.org/mentoring/project_ideas/PlantBio_p012.shtml

Table 1 - Data Form

The effect of Nitrogen based fertilizer on the growth of

Saintpaulia Ionantha (African Violets)

            Sample Taken by: ________________                  Date: _____________

                                               Location: _______________________                 

Signature: _________________________    Date: ________________________

It is expected that at the end of this experiment, the plants given nitrogen fertilizer will be larger than the plants not given fertilizer. This experiment is beneficial because it will show whether or not nitrogen fertilizers are worth spending the extra money for them. If the results expected to come from this experiment are correct, the fertilizer itself is said to be beneficial because it helps grow larger plants in a shorter amount of time.

Personnel for this experiment included Myself.

 Resume to be added after midterm.

To be added after midterm.

The experiment itself will be done over a course of 8 weeks from September 24^th through November 18^th. The timeline above shows the preparation of all components needed to perform this experiment and prepare a manuscript.

Heeb, Anuscka, Bengt Lundegardh, Tom Ericsson and Geoffrey P. Savage. 2005. Effects of nitrate-, ammonium-, and organic-nitrogen-based fertilizers on growth and yield of tomatoes. Journal of Plant Nutrition and Soil Science 168:123-129.

Jiusheng, Li, Bei Li,Minjie Rao. 2005. Spatial and temporal distributions of nitrogen and crp yield as affected by nonuniformity of sprinkler fertigation. Agricultural Water Management 76: 160-180.

Powers, La Ne. 2006. Growing, Growing, Gone! An Experiment on Nitrogen Fertilizers. Science Buddies <http://www.sciencebuddies.org/mentoring/project_ideas /PlantBio_p012.shtml>.

Sheehy, John E., P.L. Mitchell, Guy Kirk and Anaida Ferrer. 2005. Can smarter nitrogen fertilizer be designed? Matching nitrogen supply to crop requirements at high yields using a simple model. Field Crop Research 94:54-66.

Stafne, R.A., A.E. Einert and G.I. Kilngaman. 2005 Fertilizer Applications on Establishment and Growth of Three Groundcover Species in Sun and Shade. Journal of Environmental Horticulture 23: 157-161.