Capston Project

Manufacturing Wasted Eggs to Fertilizers with Liming Abilities as an Environmental-friendly Means to Induce Crop Growth

As the United States produces more than 7 billion eggs a year and manufacturers reject 3% of them, the researchers estimate more than 200 million eggs end up in landfills. In this project, the food waste will be proposed as an environmentally-friendly product that can effectively replace limestone as a cheap, available, and harmless source of lime to neutralize soil acidity and as a fertilizer to provide necessary nutrients to induce plant growth. 

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Liming is the application of calcium and magnesium rich materials in acidic soils to neutralize soil acidity. One of the most popular sources of lime, an agent to neutralize soil acidity, is ground limestone which is mostly composed of calcium carbonate (CaCO3). Eggshells are also composed mainly of calcium carbonate and the extraction of it can be done through a combination of chemical, mechanical, and thermal processes. Therefore, eggshells are a viable option to replace limestone as a liming agent. 

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However, despite the beneficial effects of liming on soil acidity, inappropriate liming rates (i.e., overliming) may result in deficiencies in micronutrients such as Fe, Mn, Cu and Zn. To resolve this problem, other parts of the eggs will be used. Eggs in their albumen and yolk contain magnesium, calcium, and micronutrients such as iron, zinc, and copper. They are also rich in mineral nutrients necessary for growth: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), sulfur (S), magnesium (Mg), carbon (C), oxygen (O), and hydrogen (H). Of the three main nutrients nitrogen, phosphorus, and potassium(N-P-K), egg yolk contains approximately 95 mg of phosphorus and 63 mg of phosphorus while eggshells contain nitrogen. This suggests that eggs can be an extremely effective fertilizer while countering side effects of liming. 

 

This research will explore the characterization of eggs and manufacture eggs into liming agents and fertilizers. The product will be compared with existing chemical fertilizers and ground limestone to investigate the environmental impact of using egg products as fertilizers and a liming agent. Vertical farming methods will be used to explore the effect of fertilizer on crops in short periods. This study aims to provide a new approach to induce crop growth while minimizing environmental damage. The proposed research will provide evidence on the potential of using eggs as a fertilizer and liming agent, providing valuable information to farmers and agriculture companies in their quest to produce sustainable and environmentally-friendly products.