EFFECTS OF FERTILIZER APPLICATION ON SOIL MOISTURE, GROUNDWATER, AND SURFACE WATER

The objective of this study was to determine if nitrates, phosphates, and sulfates from fertilizer move into and through the soil in an agricultural field and appear in the nearby stream water. This study specifically looked at nitrates, phosphates, and sulfates in soil moisture, and in nearby stream water. The study took place in an agricultural field and small creek in a large ravine in Campbell, New York. Soil moisture was collected at sites situated downslope from one another in an agricultural field that was planted with both alfalfa and timothy. The farmer applied 175 pounds of fertilizer (containing nitrogen, phosphate, sulfate, and potassium) per acre on a 10 acre plot of land on May 14^th. Samples of soil moisture and stream water were collected every 2 weeks from late April through December 2017. Rainwater was also measured and collected during this time as well. These samples were then analyzed for nitrates, phosphates, and sulfates using ion chromatography. Nitrates and phosphates are readily used up by the plants and do not make their way down through the soil. Sulfate, however, has increased with soil depth and has moved diagonally downslope; higher concentrations of sulfate exist in the last site on the steepest part of the slope. The observed changes in sulfate concentration can best be explained by the lack of ability of the plants to take up this excess amount of sulfur. Moreover, this research calls into question the need for sulfur in fertilizer. Sulfur is a micronutrient and is therefore already available to plants and crops in the natural system. High concentrations of sulfur can increase salinity within the soil and therefore decrease plant growth and crop production.