Tillage and Compaction Impact. On Soil Aggregate Associated Properties

Transcription

1 Tillage and Compaction Impact On Soil Aggregate Associated Properties Kenan Barik, Ataturk University, Turkey and Randall Reeder, Alan Sundermeier, Yogi Raut, Rafiq Islam, Stacey Reno, and Jim Hoorman Ohio State University, Ohio

2 Kenan Alan Jim Rafiq

3 Heavy farm machinery compacts the soil, both on tilled ground and no-tilled ground. Plowing and subsoiling degrade soil structure by dispersing macro-aggregates. Tillage breaks up roots, fungal hyphae and other important living organisms. No-Till minimizes soil erosion, benefits soil biology, and increases soil aggregate stability. Data on soil physical properties is useful to evaluate a soil.

4 Conclusions Compaction from a big grain cart (18 Mg/axle) affected soil aggregate properties on both continuous no-till and annually subsoiled plots. No-Till, to some extent, can improve the aggregate properties of soil.

5 Compaction research since 1988

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7 Materials and Methods Field experiment was established on Hoytville clay loam in 3 x 2 factorial arrangement of RCB design in Wood County, northwest Ohio.

8 Materials and Methods The factors were: 1) Compaction: control, 9 and 18 Mg/axle loads 2) Tillage: no-till and annual tillage (subsoiling)

9 Compaction with a 600-bu grain cart (full = 18 Mg/axle; half full = 9 Mg/axle)

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12 Results and Discussion Compaction caused a significant decrease in: Concentration of aggregates 1-2 mm Concentration of >2 mm, and Stability of macro- and micro-aggregate, MWD, GMD, and ratio of macro- and microaggregates. Compaction increased concentration of smaller aggregates <0.053 mm.

13 More compaction means more small aggregates 20 Aggregate size distribution (%) * * 5 0 * mm: y= *X mm; y = *X <0.053 mm: y = *X *X Soil compaction (Mg)

14 and fewer large aggregates 30 Aggregate size distribution (%) * >2 mm: y = *X 1-2 mm: y = *X *X mm: y *X mm: y = *X * Soil compaction (Mg)

15 Compaction increased the cone penetration resistance and bulk density. The impact was mainly with the heavier axle load (18 Mg).

16 Cone penetrometer resistance (depth, 0-30 cm) 2500 Penetration resistance (kpa) CT: y = *X +2.5*X 2 NT: y= *X + 2.6*X Soil compaction (Mg)

17 Cone penetrometer resistance (depth, 0-30 cm) 2500 Penetration resistance (kpa) CT: y = *X +2.5*X 2 NT: y= *X + 2.6*X Soil compaction (Mg)

18 Compacting load had more effect near surface 2500 Penetration resistance (kpa) cm: y = *X + 2.9*X cm: y = *X + 2.1*X Soil compaction (Mg)

19 No-Till increased cone penetration resistance and soil bulk density compared with subsoiling.

20 Cone Penetrometer resistance Penetration resistance kpa) Effects Tillage ** Soil depth ** LSD p< cm cm 0 CT Tillage * 95% **99% ***99.9% NT

21 Soil Bulk Density Soil bulk density (g cm -3 ) Effects Tillage ** Soil depth ** LSD p< cm cm 1.0 CT NT Tillage

22 9 Mg axle load had more effect on soil density near surface; Adding 9 Mg did not double the change in density. Deeper soil started at higher density; linear relationship for axle load 1.7 Soil bulk density (g cm -3 ) cm: y = (1-exp(-0.11*X)) cm: y = *X Soil compaction (Mg)

23 No-Till significantly increased: Proportion of >2 mm size aggregates Macro- and micro-aggregate stability Mean Weight Diameter (MWD) Geometric Mean Diameter (GMD) Change in soil aggregate associated properties decreased significantly with depth.

24 With No-Till, more large aggregates, fewer small ones Aggregate size distribution (%) #* CT * # * * NT >2 mm 1-2 mm mm mm mm mm mm Tillage

25 No-Till increased Stability of Macro-Aggregates Aggregate stability (%) MacAS* MicAS * AS* 20 CT Tillage NT

26 No-till increased MWD and GMD Aggregate size (um) MWD GMD * * 300 CT Tillage NT

27 As mean weight diameter (MWD) of aggregates increased: Macro-aggregate stability increased and Micro-aggregate stability decreased. 100 Aggregate stability (%) Macrogrregate stability: y = *X *X 2 Microaggregate stability: y = *X *X Mean weight diameter (um)

28 No significant interactive effects of soil depth with compaction or tillage on aggregate properties. No significant impact of compaction x tillage interaction on soil aggregate size.

29 Conclusions Compaction consistently affected soil aggregate properties, for both no-till and subsoiling systems. No-Till, to some extent, can improve the aggregate properties of soil.

30 Tillage and Compaction Impact On Soil Aggregate Associated Properties Kenan Barik, Ataturk University, Turkey Randall Reeder, Alan Sundermeier, Jim Hoorman, Yogi Raut, Rafiq Islam and Stacey Reno Ohio State University