Agenda Item 2. A review of basic concepts and terminology related to phosphorus movement from cropland to streams and rivers.

Great Lakes Protections Fund Grant 833 – Development of a Phosphorus Soil Test Metric to Reduce Dissolved Reactive

Phosphorus Loading to Lake Erie.

Team Meeting # 5July 23-24, 2013

Some Agronomic

Terms

Soil System Terms

Particulate Phosphorus

Losses

Dissolved Reactive

Phosphorus Losses

Some basic concepts and related terms that will likely be used

See handout – Some basic concepts and terminology …

Some Agronomic Terms

Critical STP for corn and

soybeans

Critical STP for wheat and alfalfa

No additional P fertilizer recommended

What is the agronomic range for soil test

values?

Tillage Terminology

NT= No-Till, MT = Mulch Till (>30%), RT = Reduced Till (15-30%) ST = Strip Till (>30%), CT= Conventional Till (plow or

<15%)

CTIC Till Type Symbol to Use:

Fall Tillage Symbols to use:

N = None, FM = Mulch >30%, FR = Reduced (Chisel/Disk<30%), FS = Fall Strip Till, FP = Fall Plow

Other terms

Mold board plowing (inversion tillage)

Vertical tillage

Incorporation

Soil Profile

Sandusky Watershed Stratified Soil Testing Program

Dissolving and runoff of broadcast fertilizer granules before incorporation.

Tile drainage

Macropores

Revised diagram for pathways of dissolved phosphorus runoff.

A comparison of maintenance phosphorus fertilizer application rates and watershed export rates of total phosphorus and dissolved reactive phosphorus.

Sediment Delivery Ratio --- lbs/acre loss at watershed divided by lbs/acre at edge of field

Enrichment Ratio --- mg P/kg SS at edge of field divided by mg P/kg soil in the cropland soil.