Fertilizer
Determination of Phosphorus Content of Fertilizer: Skill Building Lab
© 2011, Sharmaine S. Cady East Stroudsburg University
Gravimetric Analysis
Skills to build:
Using vacuum filtration Using a digital balance Using mass stoichiometry Doing a gravimetric analysis
Fertilizer Scientists estimate that the earth 's soil contains less than twenty percent of the necessary organic nutrients needed to meet our current food production. Carbon, hydrogen, and oxygen used to synthesize compounds needed for structural integrity are readily available from air and water. Nitrogen, phosphorus, and potassium, the building blocks for healthy plants, are usually not present in sufficient amounts in the soil to support plant growth. These are known as macronutrients. In addition, micronutrients, such as calcium, sulfur, and magnesium, are also necessary, but in smaller amounts.Table 1 shows the role of these nutrients in plant growth. Commercial fertilizers are inorganic or organic compounds that replenish the soil with additional nutrients to increase growth and keep plants healthy. In 2001, 53 million tons of fertilizer was used by the agricultural industry in the United States. Nitrogen fertilizers use ammonia as the building block for the production of water-soluble nitrogen-containing compounds, such as ammonium nitrate. Phosphorus is mined from natural geological deposits and mixed with sulfuric acid to make water-soluble phosphate compounds. Potassium is supplied as potash (potassium chloride) from evaporation of sea water. In the United States, the Association of American Plant Food Control Officials (AAPFCO) is concerned with consumer protection. AAPFCO works with industry to promote the safe and effective application of fertilizers in an effort to protect soil and water resources. It also oversees standard methods for fertilizer analysis to ensure that fertilizer labels are accurate and consistent with nutrient content.
Fertilizers
Table 1. Role
© 2011, Sharmaine S. Cady East Stroudsburg University
Gravimetric Analysis
Skills to build:
Using vacuum filtration Using a digital balance Using mass stoichiometry Doing a gravimetric analysis
Fertilizer Scientists estimate that the earth 's soil contains less than twenty percent of the necessary organic nutrients needed to meet our current food production. Carbon, hydrogen, and oxygen used to synthesize compounds needed for structural integrity are readily available from air and water. Nitrogen, phosphorus, and potassium, the building blocks for healthy plants, are usually not present in sufficient amounts in the soil to support plant growth. These are known as macronutrients. In addition, micronutrients, such as calcium, sulfur, and magnesium, are also necessary, but in smaller amounts.Table 1 shows the role of these nutrients in plant growth. Commercial fertilizers are inorganic or organic compounds that replenish the soil with additional nutrients to increase growth and keep plants healthy. In 2001, 53 million tons of fertilizer was used by the agricultural industry in the United States. Nitrogen fertilizers use ammonia as the building block for the production of water-soluble nitrogen-containing compounds, such as ammonium nitrate. Phosphorus is mined from natural geological deposits and mixed with sulfuric acid to make water-soluble phosphate compounds. Potassium is supplied as potash (potassium chloride) from evaporation of sea water. In the United States, the Association of American Plant Food Control Officials (AAPFCO) is concerned with consumer protection. AAPFCO works with industry to promote the safe and effective application of fertilizers in an effort to protect soil and water resources. It also oversees standard methods for fertilizer analysis to ensure that fertilizer labels are accurate and consistent with nutrient content.
Fertilizers
Table 1. Role
References: European Manufacturers Fertilizer Association Home Page.http://www.efma.org/(accessed August 2005) The Fertilizer Institute Home Page.http://www.tfi.org/ (accessed August 2005) Wink, D. J.;Gislason, S. F.; Kuehn, J. E.Working with Chemistry, 2e; W. H. Freeman & Company: New York, 2000; pp C-11-C-12. 6