『Abstract
　We measured atmospheric nutrient deposition as wet deposition and dry deposition to dry and wet surfaces. Our analyses offer estimates of atmospheric transport of nitrogen (N), phosphorus (P) and silicon (Si) in an agricultural region. Annual dry and wet deposition (ha^-1 year-1) was 0.3 kg of P, 7.7 kg of N, and 6.1 kg of Si; lower than or similar to values seen in other landscapes. N:P and Si:N imply that atmospheric deposition enhances P and Si limitation. Most P and soluble reactive P (SRP) deposition occurred as dryfall and most dry-deposited P was SRP so would be more readily assimilable by plant life than rainfall. Dry deposition of N to wet surfaces was several times greater than to dry surfaces, suggesting that ammonia (NHx) gas absorbtion by water associated with wet surfaces is an important N transport mechanism. Deposition of all nutrients peaked when agricultural planting and fertilization were active; ratios of NHx:nitrate (NOx) reflected the predominant use of NHx fertilizer. Wet deposition estimates were consistent over hundreds of km, but dry deposition estimates were influenced by animal confinements and construction. Precipitation wash-out of atmospheric nutrients was substantial nut larger rain events yields higher rates of wet deposition. Methodological results showed that local dust contaminated wet deposition more than dry; insets, bird droppings and leaves may have biased past deposition estimates; and estimating dry deposition to dry plastic buckets may underestimate annual deposition of N, especially NHx.

Keywords: atmospheric deposition; dry; nitrogen; phosphorus; precipitation; silicon』

1. Introduction
　1.1. Problem and significance
　1.2. Objectives
2. Materials and methods
　2.1. Sampling network
　2.2. Sample collection
　2.3. Sample processing and analysis
　2.4. Calculations and statistical methods
3. Results and discussion
　3.1. Comparisons between types of deposition
　3.2. Proportion of dissolved inorganic nutrients
　3.3. Local versus long-distance transport
　3.4. Site comparisons
　3.5. Nutrient concentrations
　3.6. Annual deposition
　3.7. Atmospheric washout
　3.8. Contamination
4. Conclusions
Acknowledgements
Note
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