ARE TILLAGE AND SOIL QUALITY MUTUALLY EXCLUSIVE. Dick Wolkowski Department of Soil Science University of Wisconsin

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1 ARE TILLAGE AND SOIL QUALITY MUTUALLY EXCLUSIVE Dick Wolkowski Department of Soil Science University of Wisconsin

2 WHAT IS SOIL QUALITY DEPENDS ON WHO YOU ARE: Farmer: Highly productive, sustainable soil having certain properties Naturalist: Soil in harmony with the landscape and environment Consumer: Source for plentiful and inexpensive food

3 ASSESSING SOIL QUALITY OFTEN SUBJECTIVE: Smell, feel, look, taste? Soil Quality Index MORE QUANTITATIVE Chemical ph, O.M., nutrients Physical Structure, bulk density Biological Respiration, microbial biomass

4 Pennsylvania

5 TILLAGE IS A KEY PART OF CROP PRODUCTION THE PHYSICAL MANIPULATION OF THE SOIL FOR THE PURPOSES OF: Management of previous crop residues Control of competing vegetation Incorporation of amendments Preparation of a seedbed

6 TILLAGE AFFECTS SOIL PROPERTIES RELATED TO SOIL QUALITY Crop residue cover Soil test measurements Nutrient availability Structure and aggregate stability Water relationships Temperature Soil biology Compaction and Strength

7 SURFACE CROP RESIDUE INTERACTS WITH OTHER FACTORS Impact on erosion Cooler soils Conserves moisture Affects soil physical properties Affects carbon and nutrient cycling

8 % of Acreage TILLAGE INTENSITY IN WISCONSIN VARIES BY CROP NT MT RT CT Corn Soybean Forage CTIC, 2002

9 TILLAGE EFFECT EROSION ON CLEAN-TILLED GROUND, DANE CO., WIS.

10 CROP MANAGEMENT EFFECT EROSION ON CORN SILAGE GROUND SHAWANO CO., WIS.

11 TILLAGE EFFECT ON SOIL TEST ISSUES Nutrient stratification Surface applied nutrients Crop residues Vertical and horizontal Fertilizer placement considerations How to collect a representative sample

12 SOIL TEST STRATIFICATION FOLLOWING FIVE YEARS OF TILLAGE MANAGEMENT, ARLINGTON, WIS. 6-8" 4-6" 2-4" 0-2" CH CH CH NT NT NT SOIL TEST P (ppm) SOIL TEST K (ppm) SOIL ph Wolkowski, 2003 (Corn/soybean rotation)

13 TILLAGE HAS A PROFOUND EFFECT ON THE SOIL PHYSICAL CONDITION TEN BOTTOM MOLDBOARD PLOW SET AT 11, WOOD CO., WIS.

14 Pore volume (cm 3 /cm 3 ) EFFECTS OF LONG-TERM TILLAGE ON THE PLOW LAYER PORE SIZE DISTRIBUTION MB NT Hill et al., 1985 > Pore Size

15 AGGREGATE STABILITY INFLUENCED BY Organic matter and organisms Texture Rotation Tillage IMPORTANT FOR: Aeration Water relations Productivity (Tilth)

16 HEALTHY CORN ROOT MASS

17 TILLAGE EFFECTS ON SOIL (0-2 IN.) PROPERTIES AT LANCASTER, WIS. TILLAGE STAB. AGGR. TOTAL C EARTH WORMS % g/kg No./m 2 No-till Chisel Plow Karlen et al., 1994

18 SIZE (mm) WATER-STABLE AGGREGATE SIZE IN THE 0-3 IN. DEPTH AS AFFECTED BY ROTATION AND TILLAGE FALL MB FALL CH NO-TILL 0 Kladivko et al, 1986 CC CSb SbC SbSb

19 STRENGTH (MPa) EFFECT OF TILLAGE ON CRUST STRENGTH AFTER A HEAVY RAINFALL UNGER, 1984 MB NT DAYS

20 TILLAGE EFFECTS ON SOIL TEMPERATURE Cooler temperatures associated with high residue Residue buffers temperature change Emergence and early growth affected Corn on corn no-till systems have been shown to be 5-10% less productive in Wisconsin

21 DEGREE C Residue (%) SOIL TEMPERATURE AFFECTED BY TILLAGE AND CROP RESIDUE 100 Effect on crop residue, Arlington, Chisel Strip-till No-till Effect on in-row soil temperature, Arlington, 1994 Wolkowski, " DEPTH MEASURED 4:00-5:00 PM 10 STRIP-TILL 5 CHISEL NO-TILL 0 11-Apr 18-Apr 24-Apr 2-May 9-May 16-May 23-May

22 STRIP TILLAGE OFFERS AN ALTERNATIVE TO FULL-WIDTH TILLAGE

23 EFFECT OF TILLAGE ON THE EARLY GROWTH OF CORN, ARLINGTON, WIS. TILLAGE EMERGENCE V6 V12 SILKING plt/ft g/plt % Strip-till Chisel No-till Wolkowski, 2000

24 TILLAGE AFFECTS BIOLOGICAL ACTIVITY Cooler and wetter no-till soils Slower residue decomposition Nutrient immobilization Greater denitrification potential Surface organic material promotes localized biological activity

25 EARTHWORM ACTIVITY GREATER UNDER REDUCED TILLAGE Midden

26 Total N (mg/cm 3 ) SOIL C AND N DISTRIBUTION AFTER 12 YEARS OF CONTINUOUS CORN Total C MB NT Total N MB NT Depth (in) Depth (in) Karlen et al., 1994

27 TILLAGE EFFECTS ON SOIL STRENGTH Reduced tillage soils have higher surface bulk density and penetration resistance Short-term response to occasional tillage Traffic management critical Subsoiling response is likely site dependent

28 Depth, mm TILLAGE INFLUENCES RESISTANCE TO PENETRATION Greater penetration resistance in no-till in top 6 compared to chisel when not compacted 0 50 Soil Resistance to Penetration, kpa Compacted chiseled soil has greater resistance than notill Greater penetration resistance when soil is dry Compaction effects more distinct in dryer soil /22/2000 7/20/2000 dry (36 % vs. 27 %) Arlington, Plano silt loam No-Compaction - No-tillage No-Compaction - Chisel Compacted - No-Tillage Compacted - Chisel

29 Would these guys be smiling if they really knew how much pressure this grain cart put on the ground (800 bu x 56 lb = 44,800 lb)

30 Plant growth affected - root growth - nutrient uptake - water utilization Compaction affects the soil - structure - porosity - aeration - strength

31 g/cc EFFECT OF PERIODIC PLOWING ON SOIL BULK DENSITY (0-3 in.) CT NT/PLOW NT Pierce et al., 1994

32 PERSISTANCE OF COMPACTION ALONG THE WADSWORTH TRAIL, MINNESOTA in 8-10 in 6-8 in 4-6 in 2-4 in 0-2 on RUTS Sharratt et al., 1998 OUTSIDE SOIL BULK DENSITY (g/cc)

33 SUMMARY Tillage management can greatly modify soil properties related to soil quality and crop growth Tillage intensity will impact residue management and soil consolidation Many physical, chemical, and biological properties are affected High residue systems need tweaking in Wisconsin Better traffic and tillage management will enhance soil quality and maintain productivity