TURF AND SOIL

SOIL PROFILE Topgrowth (leaves and stolons) Thatch: undecomposed organic matter (roots, shoots, stolons, rhizomes) –Decomposed by microorganisms (MO) Mat: thatch integrated with soil Soil

THATCH ½ to 1” of thatch is good Excessive thatch is BAD

WHY THATCH IS BAD 1. Root system is limited to thatch 2. Dry and temperature extremes

WHY THATCH IS BAD 3. Crowns develop in thatch

WHY THATCH IS BAD 4. Crowns can be mowed out of turf (scalping)

WHY THATCH IS BAD 5. Pathogens and insects supported by thatch 6. Reduces insecticide effectiveness

EXCESSIVE THATCH Excessive thatch due to improper management Plant growth exceeds MO activity 1. Excessive N is most common

EXCESSIVE THATCH 2. Overwatering slows MO activity Reducing oxygen in soil

THATCH 3. Over application of chemicals Reduce MO and worms

THATCH and CLIPPINGS Clippings do not contribute to thatch Mostly water, break down rapidly Stolons and rhizomes contain lignin

SOIL TEXTURE Texture: size and proportion of soil particles

SOIL TEXTURE Clay is smallest High adsorption capacity Holds water TIGHT High degree of micropores

SOIL TEXTURE Silt Holds higher amount of PLANT AVAILABLE MOISTURE

SOIL TEXTURE Sand 7 classes7 classes Solid particles with no microporesSolid particles with no micropores Good drainage through macroporesGood drainage through macropores Resistant to compactionResistant to compaction

SOIL TEXTURE Sand Little adsorptive capacityLittle adsorptive capacity Low micro organism activityLow micro organism activity

SOIL STRUCTURE Structure: arrangement of soil particles Good structure provides good pore space Good aeration to provide oxygen to roots

SOIL STRUCTURE Compaction destroys structure of soil

pH Measure of acidity and alkalinity Scale of 0 to 14, 7 is neutral Ideal pH is between 6 and 7 (slightly acidic)

pH Affects nutrient availability Iron and some micronutrients unavailable at high pH

RAISING pH Raise low pH with lime application

LOWERING pH Lower high pH… not feasible Applications of elemental sulfur lowers pH Soil pH rebounds once S used up

RAISING pH Irrigation pH injection works

RAISING pH Irrigation pH injection works

SOIL MOISTURE Saturated condition Water flows down by gravitational force

SOIL MOISTURE Unsaturated condition (macropores drained) Water moves through soil by attractive forces

SOIL MOISTURE Unsaturated condition (macropores drained) Cohesion: attraction of water molecules to each other Adhesion: attraction of water molecules to soil particles

SOIL MOISTURE Unsaturated condition (macropores drained) Capillary flow, or wicking, in any direction Roots pull water away from soil particle forces

SOIL MOISTURE Permanent wilting point: roots cannot overcome soil attractive forces

Golf Green Construction Sand/peat rootzone –California method is all sand Sand used because of –Resistance to compaction –Good drainage

Sand drains TOO MUCH –Better than draining to little Golf Green Construction

Perched water table concept Fine sand layer over coarse sand layer –Smaller pores of fine sand have greater attractive force than larger pores Holds water in root zone Maintains excellent drainage

Artificial Golf Green