1. ASSESSMENT OF CHANGES IN TOPSOIL DEPTH REDISTRIBUTION IN RELATION TO DIFFERENT TILLAGE TECHNOLOGIES MICHAELA HRABALÍKOVÁ & PETRA HUISLOVÁ hrabalikova.michaela@vumop.cz & huislova.petra@vumop.cz Research Institute for Soil and Water Conservation Žabovřeská 250, 156 27 Prague 5 – Zbraslav, Czech Republic

2.  provide comparison between a conventional and conservational primary tillage implement.  evaluate effects of soil redistribution on the spatial variability of soil profiles before and after five-tillage operation by using three different practices INTRODUCTION AND OBJECTIVES OF OUR STUDY Variability of mechanism of soil profile modification by tillage along the slope, modified figure of De Alba et al., 2004 & Zadorova et al., 2015 OBJECTIVES:

3. STUDY AREA View from the experimental plot upward View on part of the experimental plot

4. EXPERIMENT DESIGN Slope 3Slope 2Slope 1 Length (m)161150100 (+10) H min (m a.s.l.)205.3209.6 H max (m a.s.l.)225.6 221.8 SU BS + SH TS+ FS BS SH SH SU Tillage direction BS

5. EXPERIMENT DESIGN  During the year 2015  Simulation of medium-term effect (5 years approx. 5-tillage pass)  Tools: I. Mouldboard plough II. Chisel plough III. Disc harrow mouldboard plough chisel ploughdisc harrow d=250 mm, v=7-10 km/hd=250 mm, v=12-14 km/hd=105 mm, v=10-12 km/h

6. RESULTS SU BS + SH TS+ FS BS SH SH SU BS

7. RESULTS MC D M C D M C D Profile Ref. depth (cm) Difference from ref. (cm) Horizon boundaries Profile Ref. depth (cm) Difference from ref. (cm) Horizon boundaries Disc harrow Chisel plough Mouldboa rd plough Disc harrow Chisel plough Mouldboar d plough S145-9-11-15abrupt S6 40-4-8-10clear S245-11-15-13gradual S7 45-4-5-11diffuse S333269clear S8 33-5-8-14abrupt S46020 diffuse S9 38577gradual S540413 diffuseS106020 diffuse

8. RESULTS Soil loss at the summit (S1,S7 profile)Soil loss at the shoulder (S2, S6, S8 profile) tillage width (m) Net soil loss volume (m 3 ) Net soil loss (kg) Volume (m 3 ) Area (m 2 ) Mean slope length (m) Mean depth (m) Bulk density (kg/m 3 ) Volume (m 3 ) Area (m 2 ) Mean slope length (m) Mean depth (m) Bulk density (kg/m 3 ) Slope 1Disc harrow2.325100.0913309.182.5330.1113302.511.315 062.3 Chisel plough2.825100.11133012.482.5330.1513302.515.120 116.3 Mouldboard pl.4.530100.15133012.999.0330.1313303.017.423 102.1 Slope 2Disc harrow-----5.7142.5570.0412502.55.77 125.0 Chisel plough-----11.4142.5570.0812502.511.414 250.0 Mouldboard pl.-----17.1171.0570.1012503.017.121 375.0 Slope 3Disc harrow4.0100400.0415508.1162.5650.0513602.512.117 250.0 Chisel plough5.0100400.05155013.0162.5650.0813602.518.025 430.0 Mouldboard pl.13.2120400.11155027.3195.0650.1413603.040.557 588.0 In total:  Disc harrow: 29.2 m 3 => 29 tons  Chisel plough: 44.5 m 3 => 59 tons  Mouldboard plough: 75 m 3 => 102 tons

9. DISCUSSION AND CONCLUSION  First study related to tillage erosion and soil formation by tillage in the Czech Republic where the tillage erosion was neglected  Chisel and disc plough cause less soil translocation than does the mouldboard plough  The shallow tillage (<20cm depth) and up-slope tillage are recommended practice to reduce tillage erosion  Various agro-zones and soil types require further research focused on impact of tillage practices on soil formation  The critical threshold for soil loss by tillage erosion is not exactly defined asit is determined for water erosion

10. Thank you for your attention. Results were obtained as part of projects supported by the Ministry of Agriculture of the Czech Republic „Assessing and modelling tillage and gully erosion under the framework of the total soil loss evaluation of the intensively farmed land” (Project No. QJ1520028); and „Assessing and modelling tillage and gully erosion under the framework of the total soil loss evaluation of the intensively farmed land” (Project No. QJ1520028); and “Optimization in exploitation of agricultural soil to support water infiltration and retention with impacts to prediction of drought and floods in conditions of Czech Republic” (Project No. QJ1520026) “Optimization in exploitation of agricultural soil to support water infiltration and retention with impacts to prediction of drought and floods in conditions of Czech Republic” (Project No. QJ1520026)