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Why!!!. 300 head finishing Cattle open lot4 ton / head /year1200 tons / year producedManure analysisTotal N 14
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1. Iowa P-IndexRelationship to Feedlots Steve Brinkman CCA
Nutrient Management Specialist
USDA / NRCS
steven.brinkman@ia.usda.gov
515-323-2243
2. Why!!! 300 head finishing Cattle open lot
4 ton / head /year
1200 tons / year produced
Manure analysis
Total N 14 # / ton
P2O5 -- 11 # / ton
16800# Nitrogen- 13200# P2O5
3. Why!!! 35% N availability 30% application loss
100% P availability
156 bu corn 44 bu beans
125# N
36.4 ton Nitrogen Rate =33 acres + 33 acres = 66 acres
8.5 ton P- removal rate = 141.2 acres + 141.2 acres = 282.4 acres
4. Purpose of the P-Index Assess the Risk of Phosphorous delivery to surface waters
Tool to be used by Conservation Planners, Landowners and Land Users
Used to Help Make Management Decisions in Developing ways to Reduce Risks
5. Iowa Phosphorus Index Tool to assess potential for P loss from field to surface water
More comprehensive than soil test
Integrates many soil and field characteristics
Integrates many management and conservation practices
P-Index looks at source and transport factors
6. When is the P-Index Required NPDES NMPs
> 1000 animal units
found to have discharged and need a permit or declared a CAFO
DNR MMP
Confinement feeding operations over 500 animal units
7. When is the P-Index Required EQIP funds are used for waste water and manure handling needs
NRCS -- CNMP
NRCS NMPs if
8. P-Index Use Required -- NRCS Animal Manure or Organic By-Products applied
ID as designated P related impairment (DNR 303D List) http://www.iowadnr.com/water/tmdlwqa/wqa/303d.html
Current Soil Test P is very high
Soil Losses exceed T
9. Phosphorus Index Characteristics Source Factors
soil test P, (STP)
total P,
rate, methods, and timing of P applications (including manure),
erosion
10. Phosphorus Index Characteristics Transport Factors
sediment delivery,
relative field location in watershed,
soil conservation practices,
precipitation,
runoff,
tile flow/subsurface drainage
11. P-Index -Three Components