Research Methods for the Biosciences: Interactive Exercises

Table of Contents

1. CHAPTER 1: WHERE DO I BEGIN?
   1. Topic A
   2. Topic B
   3. Topic C
   4. Topic D
   5. Topic E
2. CHAPTER 2: EXPERIMENTAL DESIGN
3. CHAPTER 3: WHAT TO DO WITH RAW DATA
4. CHAPTER 4: AN INTRODUCTION TO HYPOTHESIS TESTING
5. CHAPTER 5: HYPOTHESIS TESTING: DOES MY DATA FIT AN EXPECTED RATIO?
6. CHAPTER 6: HYPOTHESIS TESTING: ASSOCIATIONS AND RELATIONSHIPS
7. CHAPTER 7: HYPOTHESIS TESTING: DO MY SAMPLES COME FROM THE SAME POPULATION? PARAMETRIC DATA
8. CHAPTER 8: HYPOTHESIS TESTING: DO MY SAMPLES COME FROM THE SAME POPULATION? NON-PARAMETRIC DATA
9. CHAPTER 9: RESEARCH, THE LAW AND YOU
10. CHAPTER 10: REPORTING YOUR RESEARCH

Topic D

Assessing the effects of perlite and humic acid as ameliorants for green compost when growing Ocimum basilicum (sweet basil)

Targets have been set to reduce the amount of biodegradable waste entering landfill sites. These wastes can be composted. The product is referred to as green compost. The student decided to examine the potential use of green composts. Green compost has several less favourable qualities including its density. It may be 'lightened' by adding other materials such as perlite.

Humic acids attack and decompose soil minerals so releasing essential cations which are taken up by plants. Small quantities of humic acid are known to improve aspects of plant growth and affect cell elongation and root initiation (e.g. Brady & Raymond, 1996).

This investigation was carried out to find an effective alternative to using peat as the primary growing media in horticulture. Information was obtained as to what makes a good growing media. This information was used both when selecting potential growing media and assessing their value.

Ocimum basilicum (sweet basil) was selected as the test plant because it is easily available, it germinates well from seed, and tolerates a broad range of pHs.

There are many ways of gathering information about plant growth. The student who carried out this investigation was training to work in the horticulture industry and therefore decided to use the time from when the seed were sown to emergence (when the cotyledons were distinguishable above the soil surface), percentage emergence, fresh and dry weight of above ground material (g), the number of true leaves and leaf area after 4 weeks.

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Draft an aim and objective. [If you would like to save a record of your answer, please type it into this Word document] Draft Aim: Assessing the effects of perlite and humic acid as ameliorants for green compost when growing Ocimum basilicum (sweet basil). Draft Objectives: In this study the undergraduate investigated three objectives: To compare two green composts in relation to a peat based media for the growth of Ocimum basilicum in terms of time to emergence (when the cotyledons were distinguishable above the soil surface), percentage emergence, fresh and dry weight of above ground material (g), the number of true leaves and leaf area after 4 weeks. The effect of perlite as a bulking agent (no perlite, 25% perlite, 50% perlite) in green compost on the growth of Ocimum basilicum as indicted by time to emergence (when the cotyledons were distinguishable above the soil surface), percentage emergence, fresh and dry weight of above ground material (g), the number of true leaves and leaf area after 4 weeks. The effect of humic acid with green compost when watered at three concentrations (no humic acid, 2.5ml l-1 water and 5ml l-1 water) on the growth of Ocimum basilicum as indicated by time to emergence (when the cotyledons were distinguishable above the soil surface), percentage emergence, fresh and dry weight of above ground material (g), the number of true leaves and leaf area after 4 weeks.