EFFECT OF TILLAGE ON PLANT GROWTH MUHAMMAD SARFARAZ 2008-ag-1574

WHAT IS TILLAGE  THE PHYSICAL MANIPULATION OF THE SOIL FOR THE PURPOSES OF: Management of previous crop residues Management of previous crop residues Control of competing vegetation Control of competing vegetation Incorporation of amendments Incorporation of amendments Preparation of a seedbed Preparation of a seedbed

SOIL PROPERTIES AFFECTED BY TILLAGE  Crop residue cover  Structure and aggregate stability  Effect on soil moisture  Soil water retention

 Infiltration  Effect on evaporation  Effect on soil microorganisms  Effect on soil nutrient uptake

SURFACE CROP RESIDUE INTERACTS WITH OTHER FACTORS  Impact on erosion  Cooler soils  Conserves moisture  Affects soil physical properties

TILLAGE EFFECT EROSION ON CLEAN-TILLED GROUND

TILLAGE HAS A PROFOUND EFFECT ON THE SOIL PHYSICAL CONDITION

AGGREGATE STABILITY  INFLUENCED BY Organic matter and organisms Organic matter and organisms Texture Texture Rotation Rotation Tillage Tillage  IMPORTANT FOR: Aeration Aeration Water relations Water relations Productivity Productivity

“HEALTHY” CORN ROOT MASS

TILLAGE EFFECTS ON SOIL (0-2 IN.) PROPERTIES TILLAGESTAB.AGGR. EARTH WORMS RUNOFF % No./m 2 Mg/ha No-till Chisel Plow

TILLAGE EFFECT ON INFILTRATION  No-till maintains large pores  Bare soil crusts  Infiltration varies during season  Wheel traffic influences infiltration

TILLAGE EFFECTS ON SOIL TEMPERATURE  Cooler temperatures associated with high residue  Residue buffers temperature change  Emergence and early growth affected  No-till systems have been shown to be 5-10% less productive

Effect on soil moisture  Tillage facilitates water penetration into the soil and increase the amount of water retained for crop use later.  Excessive shallow tillage operations result in in increase compaction which restrict root growth, air exchange, and also creates problems in soil drainge.

Soil Water Retention  Tillage effects soil water retention by changing infiltration and evaporation of water from soil surface.  Rough soil surface and depressions caused by tillage decreases runoff.s

 Effect on Evaporation  Evaporation from the soil is a major pathway of water loss created by tillage.  Surface roughness caused by loosening of upper soil layer by tillage increases the area of soil exposed to the atmoshpere and allows greater penetration of wind.

 Effect on soil Microorganisms  Appropriate tillage practices will improve the soil structure, moisture and temperature which ultimately increase the number and activity of microorganisms.

STRIP TILLAGE OFFERS AN ALTERNATIVE TO FULL-WIDTH TILLAGE

IN-ROW RESIDUE MGT. ZONE-TILL PLANTER

STRIP TILLAGE OFFERS AN ALTERNATIVE TO FULL-WIDTH TILLAGE WITH CONSERVATION AND AGRONOMIC BENEFITS

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

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

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 and chemical properties are affected  Better traffic and tillage management will enhance soil quality