 | Bednorz D. From lysimeter to field scale - Examining the transferability of lysimeter measurements to predict nitrogen leaching from tile drained arable fields and evaluating the reliability of measurement results from different lysimeter types: Diss. … Dr. rer. nat. - Leipzig: Helmholtz centre for environmental research - UFZ, 2016. - xiii, 99,[7] p.: ill., tab. - (PhD Dissertation; 11/2017). - Res. also Germ. - Bibliogr.: p.90-99.
- ISSN 1860-0387
Шифр: (Pr 1117/2017-11) 02
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Kurzfassung ..................................................... I
Summary ........................................................ IV
Figures ........................................................ IX
Tables ........................................................ XII
Abbreviations ................................................ XIII
1 Introduction ............................................... 1
1.1 Nitrate in the focus of the European water protection
policy ..................................................... 1
1.2 The role of lysimeters to answer hydrological and
nitrogen transport questions ............................... 4
1.3 Numerical simulations to mind the gap between lysimeter
and field scale ............................................ 7
1.4 Objectives ................................................. 8
2 Material and Methods ...................................... 11
2.1 Experimental studies to examine the transferability from
lysimeter to field scale .................................. 11
2.1.1 Study area of the lysimeter experiments and the
field trial in Saxony-Anhalt ....................... 11
2.1.2 Lysimeter design - Non-weighable gravitation
lysimeters (NWGL) .................................. 13
2.1.3 Field conditions - Backwater influenced (BW) and
groundwater influenced (GW) ........................ 14
2.1.4 Crop rotation and soil tillage at the lysimeters
and the field trial ................................ 17
2.1.5 Lysimeter and field measurements ................... 18
2.2 Experimental studies to evaluate the impact of the lower
boundary on lysimeter measurements ........................ 22
2.2.1 Study area of the lysimeter experiments in
Brandenburg ........................................ 22
2.2.2 Experimental setup - Tension-controlled lysimeter
(TL) - Gravitation lysimeter (GL) - Soil
measuring station ................................. 23
2.3 Numerical simulations with HYDRUS 1D/2D ................... 26
2.3.1 Governing equations describing water flow and
simplified solute transport ........................ 26
2.3.2 Initial and boundary conditions .................... 28
2.3.3 Model setups ....................................... 32
2.3.3.1 From lysimeter to field scale - NWGL and field
BW-model ....................................... 32
2.3.3.2 The impact of soil heterogeneity - Combined
BW-GW-model .................................... 33
2.3.3.3 The impact of the lower boundary condition -
TL-and GL-model ................................ 34
2.3.4 Goodness of fit criteria ........................... 35
3 Results ................................................... 37
3.1 The transferability from lysimeter to field scale ......... 37
3.1.1 Measured water balances of the NWGL and the
backwater-influenced field BW ...................... 37
3.1.2 Simulated water balances of the NWGL and the
backwater-influenced field BW ...................... 39
3.1.2.1 Calibration results and upper boundary for
validation ..................................... 39
3.1.2.2 NWGL-model ..................................... 41
3.1.2.3 Field BW-model ................................. 42
3.1.3 Evaluating deviating measured and modelled
outflow rates at both scales ....................... 44
3.2 The impact of soil heterogeneity on water flow and
NCb-N-leaching ............................................ 47
3.2.1 Indicators for describing the chemical milieu of
both fields - BW and GW ............................ 47
3.2.2 Crop yields and nitrogen-uptake .................... 48
3.2.3 Nitrogen analysis in the soil of field BW and GW ... 48
3.2.4 Soil moisture and NO3N-concentration in soil
solution of field BW and GW ........................ 49
3.2.5 Drain flow and NCh-N-discharge via tile drains ..... 51
3.2.6 NG>N-concentration in back-/ groundwater of field
BW and GW .......................................... 55
3.3 Using lysimeters to simulate the impact of soil
heterogeneity ............................................. 56
3.3.1 Simulated water balance of both fields based on
the NWGL-measurements .............................. 56
3.3.2 Simplified solute transport model .................. 57
3.4 The impact of the lower boundary on the flow regime of
lysimeters ................................................ 60
3.4.1 Measured water balances at the TL and the GL ....... 60
3.4.2 Measured depth depending soil moisture of the TL,
GL and the undisturbed soil ........................ 62
3.4.3 Measured tension at the lower boundary of the TL,
GL and the undisturbed soil ........................ 63
3.4.4 Simulated water balances of the TL and the GL ...... 65
3.4.4.1 Model calibration .............................. 65
3.4.4.2 Model validation ............................... 66
4 Discussion ................................................ 75
4.1 The transferability of lysimeter data to describe water
flow on field scale ....................................... 75
4.2 The impact of soil heterogeneity on water flow and
nitrogen-dynamic at field scale ........................... 77
4.3 Combined lysimeter measurements and simplified
simulations to predict water flow and nitrogen-transport
at field scale with spatial soil heterogeneity ............ 81
4.4 Advantages and drawbacks of recent lysimeter
technologies .............................................. 83
5 Conclusions ................................................. 86
6 References .................................................. 90
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