Polk County, IA Extension Office & Soil Testing Directory
Welcome to the official directory resource for Polk County, IA. Connecting local homeowners, urban gardeners, and commercial growers with Iowa's land-grant university extension resources, state soil testing lab services, and Master Gardener volunteer clinics.
1. Extension Office Contact Details & Operational Hours
The ISU Extension and Outreach - Polk County serves as the primary educational extension center in Polk County. Visit or call during standard operational hours for agricultural advice, soil sample kits, and youth 4-H programs.
| Official Office Name: | ISU Extension and Outreach - Polk County |
| Physical Address: | 1625 Adventureland Drive, Suite A, Altoona, IA 50009 |
| Direct Phone Desk: | (515) 957-5760 |
| Email Contact: | polk4h@iastate.edu |
| Office Hours: | Monday – Friday: 8:00 AM – 5:00 PM |
| Official Web Portal: | https://www.extension.iastate.edu/polk/ |
2. Official Soil Testing Laboratory & Pricing
Testing your soil is the single most important step before adding fertilizers or agricultural lime. The official testing laboratory serving Polk County is ISU Soil and Plant Analysis Laboratory Partners.
| Official Testing Lab: | ISU Soil and Plant Analysis Laboratory Partners |
| Lab Location: | 2104 Agronomy Hall, Ames, IA 50011 |
| Routine Sample Fee: | $15 routine soil analysis |
| Expected Turnaround: | 5 to 7 business days |
| Official Lab Website: | https://www.extension.iastate.edu/ |
How to Collect and Submit a Soil Sample in Polk County:
- Pick up a Soil Kit: Pick up official sample boxes and submittal forms at the ISU Extension and Outreach - Polk County (1625 Adventureland Drive, Suite A, Altoona, IA 50009).
- Collect Sub-Samples: Use a clean stainless steel trowel to take 10 to 12 soil cores from a 4-to-6-inch depth across your garden or lawn area.
- Air-Dry: Mix sub-samples in a clean plastic bucket and air-dry on clean paper at room temperature (never use an oven).
- Submit Sample: Return your filled soil box to the extension office or mail directly to ISU Soil and Plant Analysis Laboratory Partners.
3. Master Gardener Volunteer Program & Plant Clinic
The Polk County Master Gardeners provides free plant disease diagnostics, lawn care advice, and eco-friendly pest management tips.
| Program Name: | Polk County Master Gardeners |
| Plant Clinic Hours: | Monday, Wednesday, Friday: 9:00 AM – 12:00 PM (Note: Plant clinics run seasonally; call office during winter months) |
| Direct Helpline Phone: | (515) 957-5760 |
| Program Portal: | https://www.extension.iastate.edu/polk/master-gardener-program |
Volunteer Training: 10-week Iowa State University extension training course.
4. Regional Soil & Growing Snapshot for Polk County
USDA Plant Hardiness Zone: Zone 5b
Natural Soil Profile: Deep Prairie Mollisols (Tama Silt Loam)
Popular Local Crops: Corn, soybeans, sweet corn, apples, brassicas
Extension Specialist Tip: Iowa soils are rich in organic matter; regular testing ensures proper balance of potassium.
5. 🧮 Interactive Soil Amendment Calculator for Polk County
Estimate the recommended agricultural limestone or elemental sulfur needed to adjust your garden soil pH based on local Deep Prairie Mollisols (Tama Silt Loam) characteristics.
📚 Recommended Extension Guides & Soil Articles
Learn more about interpreting your Polk County extension soil test report and managing plant nutrients:
Frequently Asked Questions (Polk County Directory)
The ISU Extension and Outreach - Polk County is located at 1625 Adventureland Drive, Suite A, Altoona, IA 50009. You can call their main desk directly at (515) 957-5760 during standard business hours (Monday – Friday: 8:00 AM – 5:00 PM).
Standard soil analysis for Polk County garden samples through ISU Soil and Plant Analysis Laboratory Partners costs $15 routine soil analysis. Check with the office for special sample types.
You can reach the Polk County Master Gardeners hotline by calling (515) 957-5760 during plant clinic hours (Monday, Wednesday, Friday: 9:00 AM – 12:00 PM).
Polk County falls primarily within USDA Plant Hardiness Zone 5b. Local soil is characterized as Deep Prairie Mollisols (Tama Silt Loam).
Written & Verified by Sahajul
Verified Author & Founder
Sahajul is an independent agricultural data researcher based in India and founder of LocalSoilLab.com. He specializes in compiling, structuring, and verifying US land-grant university extension services, soil lab testing fee schedules, and county Master Gardener contact directories directly from official .edu and USDA NIFA portals.