ASSESSMENT OF CHANGES IN TOPSOIL DEPTH REDISTRIBUTION IN RELATION TO DIFFERENT TILLAGE TECHNOLOGIES MICHAELA HRABALÍKOVÁ & PETRA HUISLOVÁ & Research Institute for Soil and Water Conservation Žabovřeská 250, Prague 5 – Zbraslav, Czech Republic

 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:

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

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

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

RESULTS SU BS + SH TS+ FS BS SH SH SU BS

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 S abrupt S clear S gradual S diffuse S333269clear S abrupt S46020 diffuse S gradual S diffuseS diffuse

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 harrow Chisel plough Mouldboard pl Slope 2Disc harrow Chisel plough Mouldboard pl Slope 3Disc harrow Chisel plough Mouldboard pl 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

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

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. QJ ); and „Assessing and modelling tillage and gully erosion under the framework of the total soil loss evaluation of the intensively farmed land” (Project No. QJ ); 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. QJ ) “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. QJ )