Record Details
Long-term fertilizer input influences total and bioavailable metal in agricultural soils and crops
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Long-term fertilizer input influences total and bioavailable metal in agricultural soils and crops |
| Names |
Perez, Angela L.
(creator) Anderson, Kim A. (advisor) Curtis, Lawrence R. (advisor) |
| Date Issued | 2008-07-24T22:40:46Z (iso8601) |
| Note | Graduation date: 2009 |
| Abstract | Protection of the quality and integrity of food supplies is of global concern. Crops can accumulate non-nutritive and sometimes toxic metals and metalloids. Accumulated metals/metalloids can come in part, from fertilizers, which may contain variable levels of non-nutritive metals or metalloids such as arsenic (As), cadmium (Cd), lead (Pb), nickel (Ni), and mercury (Hg). Metal bioavailability measurements can estimate crop metal accumulation and potential offsite movement. Diffusive Gradients in Thin Films (DGT) are used to measure labile, considered to be bioavailable, metal in soil solution. The DGT technique was applied in diverse agricultural soils receiving various applications of phosphate fertilizers. DGT was found to be marginally predictive of Cd accumulated in the edible portion of wheat (Triticum aestivum L.) and potato crops (Solanum tuberosum). A distinct approach was developed to estimate short and long-term changes to total and labile metal concentrations using a uniquely calculated distribution coefficient (Kd-BIO). Kd-BIO values for Cd and Ni did not decrease over the study period, indicating that soils may serve as a long-term contaminant sink. For As and Pb, there was a tendency for the Kd (As) and Kd-BIO (Pb) values to decrease with treatment and with yearly applications. If these tendencies were to continue, they may have long term implication for human health risk assessment. In general, total recoverable As, Pb, and Hg did not increase with fertilizer treatment level or over time in agricultural soils. Labile As and Pb dose response with fertilizer treatment was site specific. As and Pb were not detected in either crop throughout the study. Cd, Ni, and Hg were measured in wheat and potato. Kd-BIO was found to be a strong indicator of Ni and Cd accumulation in crops. Transfer coefficients (Tc) for Hg were calculated and determined to increase with time. Finally, the use of chemical profiling techniques to identify the geographic growing region of three fruits strawberry (Fragaria x ananassa), blueberry (Vaccinium caesariense/ corymbosum, and pear (Pyrus communis) was considered. The data were modeled with successful regional, sub-regional, and varietal classification ranging from 70 to 100% depending on commodity and model. |
| Genre | Thesis |
| Topic | bioavailability |
| Identifier | http://hdl.handle.net/1957/9090 |
