UVM Theses and Dissertations
Format:
Print
Author:
Geibel, Justin
Title:
Dept./Program:
Plant and Soil Science
Year:
2014
Degree:
M.S.
Abstract:
Tile drainage is a common practice in the Northeast, and studies have suggested that tile lines are, a, major source ofdillsolved phosphorus (P) from agricultural fields. New techniques in drainage water management (DWM), such as the instillation of water control structures, (WCS), may may allow more control over the water table in agricultural fields, and reduce P losses. The effects of DWM on phosphorus leaching and transport to surface water are still unclear. Our primary objective is to use field scale implementation and monitoring to compare P loading from free-drained tiles and DWM tiles in manure amended agricultural field. Measurements include soluble reactive P (SRP) and total P (TP) loads from 4 free-drain and 4 DWM tile ends in a 15 acre experimental field at W.H. Miner institute in Clinton County New York. In addition, laboratory soil column leaching and saturation experiments were conducted to simulate potential changes in P. solubility under flooded soil conditions possible with DWM implementation.
Preliminary data from the field study show a 34% decrease in TP loading rates in the DWM tiles, with the largest differences occurring during high flow events. In addition, SRP has been found to contribute a large fraction of the total P loss from all tiles (~40-80%). The highest P concentrations (52.28mg/L TP and 45.23mg/L SRP) were observed in a free-flow tile while the highest concentrations in a DWM tile were 14.74 and 9.93 mg/L TP and SRP respectively. Although some differences in concentration are observed, the major treatment effect seems to be driven mainly by a reduction in effluent volume not chemistry. Results from the soil column experiments show no significant increase in P leaching under flooded, reduced conditions in the DWM columns (21 d holdback) compared to freely drained columns. This suggests that in this soil type, typical of Northern NY, DWM techniques can reduce the overall amount of P lost from agricultural fields to surface water throughout the year.
Preliminary data from the field study show a 34% decrease in TP loading rates in the DWM tiles, with the largest differences occurring during high flow events. In addition, SRP has been found to contribute a large fraction of the total P loss from all tiles (~40-80%). The highest P concentrations (52.28mg/L TP and 45.23mg/L SRP) were observed in a free-flow tile while the highest concentrations in a DWM tile were 14.74 and 9.93 mg/L TP and SRP respectively. Although some differences in concentration are observed, the major treatment effect seems to be driven mainly by a reduction in effluent volume not chemistry. Results from the soil column experiments show no significant increase in P leaching under flooded, reduced conditions in the DWM columns (21 d holdback) compared to freely drained columns. This suggests that in this soil type, typical of Northern NY, DWM techniques can reduce the overall amount of P lost from agricultural fields to surface water throughout the year.