Education Standards
https://oceanservice.noaa.gov/facts/eutrophication.html
Image of Eutrophication
Introduction to Fertilizers
Overview
This is a short module on fertilizers. In it, you will find the following different topics such as: definition of a fertilizer, dharacteristics of organic and inorganic fertilizers. the process of eutrophication and its relationship to fertilizer use, the purpose for and definition of compost (sustainability), and how to compost.
In addition to being an introduction on fertilizers, this module is also designed for students to start thinking about sustainability and how to limit negative impacts on the environment.
What are Fertilizers?
Introduction
Fertilizers are substances that are added to the soil to provide essential nutrients necessary for plant growth. There are two main types: organic and inorganic fertilizers. The former includes materials derived from plants or chemicals, whether that be feces or decomposed matter. The latter includes man-made and chemical substances.
Every bag of fertilizer contains a label for the % amount of each of three key nutrients in the bag by weight. In order, the numbers are read from left to right and represent nitrogen (N), phosphorus (P), and potassium (K) levels in that bag.
Review: A fertilizer bag has a label "8-6-2." What % of nitrogen, phosphorus, and potassium are in the bag?
Inorganic vs. Organic Fertilizers
Here is a comprehensive table with some of the main characteristics of organic and inorganic fertilizers.
| Organic Fertilizers | Inorganic Fertilizers |
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After reading through the table, answer the following questions in your own words:
- Which type of fertilizer should farmers use? Organic, inorganic, or both types of fertilizers?
- Are organic fertilizers more accessible than inorganic fertilizers?
- What are the pros and cons of organic and inorganic fertilizers?
Fertilizer Pollution
Farmers typically use both kinds of fertilizers because each serves a different role on agricultural lands. Organic fertilizers typically help with soil quality while inorganic fertilizers help with efficiency. Nonetheless, the inappropriate use of inorganic fertilizers are a major source of nutrient pollution in some waterways.
When too many nutrients are added to a field, wet weather events cause the nutrients to seap out and collect in water bodies located downstream. Here, the nutrients are then taken up by aquatic microorganisms and create deadly algal blooms that devasate entire ecosystems. This process is called eutrophication and to learn more about it, visit the website below where the National Ocean and Atmospheric Association (NOAA) has outlined the causes and effects of eutrophication.
Answer the following question in your own words
- What management practices can be applied to account for this issue?
Composting
Farmers are not the only ones who use fertilizers, but individuals who are less experienced in growing plants will be even more likely to misapply inorganic fertilizers. Luckily, most individuals are not expected to grow food at the rate farmers do, so individuals can make better use of organic fertilizers instead. In fact, a sustainable way of using the organic wastes produced at home is to use it compost it and use it as an organic fertilizer.
Compost is a type of organic fertilizer.
Composting is the process of creating compost, or the optimazation of conditions for decomposition.
Ideally, any waste generated by individuals should be kept in three separate piles:
- Recycle: plastics, paper, and glass
- Compost: for browns (carbon-rich) and greens (nitrogen-rich)
- Browns: dead leaves, branches, sawdust...
- Greens: grass clippings, food (fruit and vegetable) scraps, ...
- Trash: all other items
Apply Concepts: Composting
Composting is a sustainable way of using waste and improving soil quality, it also limits the dependency on inorganic fertilizers which are known to be major sources of pollution. However, a major challenge when it comes to composting for the first time is figuring out what items can be added to a compost bin and what cannot. This was briefly outlined in the previous section, but below is an assignment to help you learn how and what to compost.
Assignment:
- Find a partner.
- Create a table with 2 columns. At the top of the first column, title it Compostable. At the stop of the second column, title it Non-Compostable.
- Work with your partner to compile a list of at least 3 items in each column.
- At the end, example why the non-compostable items cannot be composted.
Additional Practice:
For more practice on being sustainable and separating waste into apporpriate bins, feel free to play online game below, created by National Geographic.