Subsurface tile drainage
is a common management practice implemented by farmers throughout the Midwest
in fields that have poorly drained soils. Tile drainage has several benefits
including increased productivity, reduced erosion, and increased
trafficability. However, relatively little is known about the long-term change
of soil properties that may occur as a result of subsurface drainage. Careful monitoring of
tile drains at the long-term experimental site at the Southeast Purdue
Agricultural Center led to the observation of faster drain flow than in the
past, with hydrographs of the flow showing flashier peaks, suggesting that more
preferential flow paths have developed over time. The overall goal of this
study was to characterize possible evolution of physical and hydraulic
properties of this silt loam soil after 35 years of subsurface drainage. Bulk
density and water retention were measured in May of 2018 at 0-5 cm, 5-15 cm,
and 15-30 cm in all plots and again in July of 2019 in the 5 m and 40 m
spacings at four different horizons down to depths of approximately 100 cm,
rather than set depth increments. Bulk density results from both sets of
sampling show the 5 m spacing to have a significantly lower bulk density than
the 40 m spacing in the top 30 cm of soil, although the difference was small.
Differences in water retention among treatments were too small to be physically
meaningful. Saturated hydraulic conductivity results measured by three
different methods were highly variable and no differences were detected. In
soils with naturally weak structure, low organic matter, and low clay content,
like the soil in this study, the processes responsible for soil aggregation,
structure stabilization, and lowering bulk density are inherently slow and may require longer than 35 years of
subsurface drainage to produce significant changes in the physical properties measured.
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/12388502 |
| Date | 15 June 2020 |
| Creators | Daniel T Welage (8908151) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/Long-term_Subsurface_Drainage_Effects_on_Soil_Physical_and_Hydraulic_Properties/12388502 |
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