Kentucky State University
Investigating the Impact of Animal Manures on Ammonia and Nitrate Concentrations in Field-Grow n Turnips
Grade Level at Time of Presentation
Senior
Major
Chemistry
Minor
Biology
Institution
Kentucky State University
KY House District #
6
KY Senate District #
6
Faculty Advisor/ Mentor
George Antonious, PhD
Department
Environmental Studies
Abstract
The use of organic nitrogen fertilizer in agricultural production systems increases crop yields with relatively little cost to the farmer. Ammonia (NH3) in animal manures reacts with water to form ammonium ions (NH4 +) that quickly binds to the negatively charged soil organic matter and clays. In soil, NH4 + is taken up by plant roots and transferred into nitrates (NO3 –) that can also be absorbed by plants roots. NO3 – becomes a problem only if exceeded the allowable limits in food. We investigated the impact of animal manures (sewage sludge SS, horse manure HM, chicken manure CM, vermicompost Vermi), commercial organic fertilizer Org, inorganic fertilizer Inorg, and no-manure NM native soil on the concentrations of NH4+ and NO3 - in the shoots and roots of three varieties of turnips, Brassica rapa (Purple Top White Globe PTWG, Scarlet Queen Red SQR and Tokyo Cross TC). Overall NO3 – concentrations were greater in the shoots compared to the roots. The concentration of NH4 + averaged 20.2, 12.8, and 8.9 µg g-1 fresh turnip roots, whereas NO3 – values averaged 107.6, 64.1, and 62.9 µg g-1 fresh turnip roots in varieties SQR, PTWG, and TC, respectively. Results also showed that Inorg, Vermi, and SS amended soil significantly increased NO3 – concentrations in turnip roots compared to the roots of plants grown in control treatments. Results revealed that none of the three turnip varieties tested could cause any NO3 –adverse effects on human average daily consumption. Similarly, consuming turnip roots grown in any of the animal manures tested do not represent any hazardous issues.
Investigating the Impact of Animal Manures on Ammonia and Nitrate Concentrations in Field-Grow n Turnips
The use of organic nitrogen fertilizer in agricultural production systems increases crop yields with relatively little cost to the farmer. Ammonia (NH3) in animal manures reacts with water to form ammonium ions (NH4 +) that quickly binds to the negatively charged soil organic matter and clays. In soil, NH4 + is taken up by plant roots and transferred into nitrates (NO3 –) that can also be absorbed by plants roots. NO3 – becomes a problem only if exceeded the allowable limits in food. We investigated the impact of animal manures (sewage sludge SS, horse manure HM, chicken manure CM, vermicompost Vermi), commercial organic fertilizer Org, inorganic fertilizer Inorg, and no-manure NM native soil on the concentrations of NH4+ and NO3 - in the shoots and roots of three varieties of turnips, Brassica rapa (Purple Top White Globe PTWG, Scarlet Queen Red SQR and Tokyo Cross TC). Overall NO3 – concentrations were greater in the shoots compared to the roots. The concentration of NH4 + averaged 20.2, 12.8, and 8.9 µg g-1 fresh turnip roots, whereas NO3 – values averaged 107.6, 64.1, and 62.9 µg g-1 fresh turnip roots in varieties SQR, PTWG, and TC, respectively. Results also showed that Inorg, Vermi, and SS amended soil significantly increased NO3 – concentrations in turnip roots compared to the roots of plants grown in control treatments. Results revealed that none of the three turnip varieties tested could cause any NO3 –adverse effects on human average daily consumption. Similarly, consuming turnip roots grown in any of the animal manures tested do not represent any hazardous issues.