1. High Rock Lake Watershed:
Agricultural Study
Deanna L. Osmond
Department of Soil Science, NC State University
and
Kathy Neas
NCDA&CS, Statistics Division/
USDA-National Agriculture Statistics Service

2. High Rock Lake Watershed

3. High Rock Lake Watershed Land Use

4. What We Wanted to Know What crops are grown? Do farmers soil test?
What is the rate of fertilizer application?
What is the rate of organic waste application?
What are erosion rates?
What conservation practices do farmers use?
How many buffers exist?
What are the livestock types and rates?
Farm demographics

5. How Was the Survey Conducted?
Area Frame Sampling
Acreage and crops by county
Fertilizer or animal waste application rates
Nutrient management practices
Soil testing and soil test P
Conservation practices
Erosion rates
Livestock types and amounts
Demographics
Thanks to Charles Proctor and Steve Pratt

6. Results of High Rock Lake Agricultural Survey

7. Basic Information Fields selected 1523 agricultural fields sampled
49 fields not sampled due to refusals, inaccessibility or not being agricultural
Average field size = 12.5 acres (<1 – 244 acres)
Producers
Demographics
51% agriculture was primary income source
36% agriculture was secondary income source
Nutrient Management Behavior
75% farmers make their own nutrient management decision; 70% apply their own nutrients
13% farmers do not add fertilizer

8. County
Crop Type Acreage (%)
Pasture
Hay
Crop
Alexander 72 22 6
Caldwell 34 29 37
Davidson 33
Davie 53 8 39
Forsyth 38 26 36
Iredell 10 54
Rowan 31 17 52
Stokes 40
Surry 58 15 27
Watauga
100 --
Wilkes 64 3
Yadkin

9. Erosion Rates, Soil Sampling, and Soil Test Phosphorus (P)
Average erosion is very low (0.6 ton per acre)
95% of farmers soil test
Average soil test phosphorus ranges from medium (34) to very high (218)
Some soils need phosphorus
Some soils do not need phosphorus

10. Best Management Practices
~75% of all fields with streams had buffers
Range 52% to 100%
Average buffer width > 200 feet
~70% of all tilled fields in conservation tillage

11. Nitrogen Application Fescue hay = 22 lb N ac-1
55% of the 448 hay fields are fertilized, whereas 45% are NOT
Fescue pasture = 17 lb N ac-1
31% of the 531 fields are fertilized, while 69% are NOT
Soybeans = 10 lb N ac-1
Other crops at recommended N rates
Nitrogen applications relative to crop needs are less than the recommended nitrogen application rates due to large land areas in pasture and hay

12. Phosphorus Application
60% of the fields were NOT fertilized with P
40% of the fields were fertilized with P
When farmers apply P, they do not always follow soil test P recommendations. This is often due to the nutrient imbalance in animal waste.

13. Organic Applications Organic applications to 2299.9 acres (~12%)
85% poultry (87% applied to hay or pasture)
15% dairy (60% applied to hay or pasture)
Counties with organic applications: Alexander, Caldwell, Davidson, Iredell, Rowan, Stokes, Surry, Wilkes, and Yadkin
Nitrogen application range of 10 lb ac-1 yr-1
to 239 lb N ac-1 yr-1 (less than or equal to N recommendation
Phosphorus application range of 10 lb ac-1 yr-1 to 239 lb ac-1 yr-1
15%

14. Livestock
Majority of animals are cattle but we found horses, goats, sheep, llamas, donkeys, buffalo, alpacas, mules, pigs, and chickens (non-commercial)
Average livestock density is appropriate for all counties except Caldwell, Davie, Forsyth, and Surry

15. North Carolina Nutrient Assessment Tool (NCANT)
Low nitrogen losses
Phosphorus loss ratings for all counties were low, except Alexander (medium) W)

16. Conclusions Mostly low intensity agriculture
Cropping systems lead to low erosion
Buffers frequent
Most fields under fertilized, particularly for nitrogen
High use of soil testing
Average county soil test phosphorus is high/very high
Nutrient loss tool for cropland and pasture suggests that N and P losses from agricultural fields are low

17. Can Improvements Be Made?
Limited opportunities for conservation practices include:
Additional buffers or livestock exclusion
Reduced stocking rates in some fields
Match phosphorus applications with crop phosphorus needs

18. Questions? Thanks to: NCDA&CS Enumerators Producers
NCDENR EPA funds