Author
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Vigil, Merle |
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Submitted to: Colorado Conservation Tillage Association Annual Conference Proceedings
Publication Type: Proceedings Publication Acceptance Date: 1/30/2003 Publication Date: 2/3/2004 Citation: Vigil, M.F. 2004. Fate and transformation of fertilizers in soils. Presented at the 15th Annual Winter Conference of the Colorado Conservation Tillage Association (The High Plains No-till Conference) Feb. 4-5, Greeley, Colorado. p. F1-F6. Interpretive Summary: Nitrogen (N) and phosphorous (P) fertilizers when applied to soil are transformed into chemical species that differ substantially from their original form. How these fertilizers are managed will affect these transformations and can have either positive or negative environmental impacts. In this review, we provide a summary of the major chemical and biological transformations of chemical fertilizers in soil. The review quantifies how fast the transformations happen, the effects of temperature and how much of the original chemistry is transformed. The review summarizes how fertilizer source and placement affects the amount and rate of transformation. The review summarizes current knowledge about the size of fertilizer retention zones in soil, the time required for retention zone formation and quantifies the affect of soil type on retention zone size. The review also summarizes laboratory data on the affect crop residues have on the microbial tie up of fertilizer N in soils. The review includes calculations which demonstrate that broadcasting of water soluble fertilizer N has 17 times more soil to fertilizer contact then banded application. Technical Abstract: Nitrogen (N) and phosphorous (P) fertilizers when applied to soil are transformed into chemical species that differ substantially from their original form. These transformations ultimately affect the efficiency of crop uptake and can have significant environmental impact. In this review, we provide a summary of the major chemical and biological transformations of chemical fertilizers in soil. The review quantifies rates and amounts of nitrification as affected by fertilizer source and placement and quantifies the affect of soil temperature on rate. The review also summarizes current knowledge about the size of ammonia retention zones in soil, the time for retention zone formation and quantifies the affect of soil texture on retention zone size. The review also summarizes laboratory data on the affect crop residues have on immobilization of fertilizer N in soils. The review includes calculations which demonstrate that broadcasting of ammoniacal sources of N has 17 times more soil to fertilizer contact then banded application. |
