Sebastian County, AR Extension Office & Soil Testing Directory
Welcome to the official directory resource for Sebastian County, AR. Connecting local homeowners, urban gardeners, and commercial growers with Arkansas's land-grant university extension resources, state soil testing lab services, and Master Gardener volunteer clinics.
1. Extension Office Contact Details & Operational Hours
The University of Arkansas System Division of Agriculture Extension - Sebastian County serves as the primary educational extension center in Sebastian County. Visit or call during standard operational hours for agricultural advice, soil sample kits, and youth 4-H programs.
| Official Office Name: | University of Arkansas System Division of Agriculture Extension - Sebastian County |
| Physical Address: | Fort Smith, Arkansas 72901 |
| Direct Phone Desk: | (051) 555-0199 |
| Email Contact: | sebastian@uaex.uada.edu |
| Office Hours: | Monday – Friday: 8:00 AM – 4:30 PM |
| Official Web Portal: | https://soiltest.uark.edu/ |
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 Sebastian County is University of Arkansas Soil Testing and Research Laboratory.
| Official Testing Lab: | University of Arkansas Soil Testing and Research Laboratory |
| Lab Location: | 1366 W. Altheimer Dr, Marianna, AR 72360 |
| Routine Sample Fee: | $0 (Free routine testing for Arkansas residents) |
| Expected Turnaround: | 5 to 7 business days |
| Official Lab Website: | https://soiltest.uark.edu/ |
How to Collect and Submit a Soil Sample in Sebastian County:
- Pick up a Soil Kit: Pick up official sample boxes and submittal forms at the University of Arkansas System Division of Agriculture Extension - Sebastian County (Fort Smith, Arkansas 72901).
- 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 University of Arkansas Soil Testing and Research Laboratory.
3. Master Gardener Volunteer Program & Plant Clinic
The Sebastian County Extension Master Gardener Volunteers provides free plant disease diagnostics, lawn care advice, and eco-friendly pest management tips.
| Program Name: | Sebastian County Extension Master Gardener Volunteers |
| Plant Clinic Hours: | Tuesday & Thursday: 9:00 AM – 12:00 PM (Note: Plant clinics run seasonally; call office during winter months) |
| Direct Helpline Phone: | (051) 555-0199 |
| Program Portal: | https://soiltest.uark.edu/ |
Volunteer Training: Comprehensive horticulture training conducted by University of Arkansas System Division of Agriculture Extension.
4. Regional Soil & Growing Snapshot for Sebastian County
USDA Plant Hardiness Zone: Zone 7b / 8a
Natural Soil Profile: Arkansas River Alluvial Silt Loam & Sandy Clay
Popular Local Crops: Tomatoes, strawberries, watermelons, soybeans, rice
Extension Specialist Tip: Arkansas residents enjoy free state routine soil testing. Sample garden beds in autumn to prepare for spring.
5. 🧮 Interactive Soil Amendment Calculator for Sebastian County
Estimate the recommended agricultural limestone or elemental sulfur needed to adjust your garden soil pH based on local Arkansas River Alluvial Silt Loam & Sandy Clay characteristics.
📚 Recommended Extension Guides & Soil Articles
Learn more about interpreting your Sebastian County extension soil test report and managing plant nutrients:
📦 Recommended Mail-In Soil Test Kits & Meters
FTC Affiliate Disclosure: We may earn a commissionIf you need immediate results without waiting for university mail-in lab turnaround times, these top-rated professional home soil test kits provide fast pH, N, P, and K diagnostic analysis:
MySoil Soil Test Kit
Professional mail-in kit analyzed by accredited labs. Returns 13 essential nutrient values (N, P, K, pH, Micronutrients) & customized fertilizer recommendations via app.
Luster Leaf Rapitest 1601
Popular color-comparator kit for 10 instant soil tests (pH, Nitrogen, Phosphorus, Potash). Includes tailored plant preference chart.
Sonkir 3-in-1 Soil Tester
Instant probe sensor for soil moisture, pH, and sunlight levels. Requires no batteries. Perfect for potted plants, lawns, and raised beds.
📋 Request Local Extension & Lawn Testing Assistance in Sebastian County, AR
Need help interpreting your lab results or finding local agricultural extension agents? Fill out the brief form below:
Frequently Asked Questions (Sebastian County Directory)
The University of Arkansas System Division of Agriculture Extension - Sebastian County is located at Fort Smith, Arkansas 72901. You can call their main desk directly at (051) 555-0199 during standard business hours (Monday – Friday: 8:00 AM – 4:30 PM).
Standard soil analysis for Sebastian County garden samples through University of Arkansas Soil Testing and Research Laboratory costs $0 (Free routine testing for Arkansas residents). Check with the office for special sample types.
You can reach the Sebastian County Extension Master Gardener Volunteers hotline by calling (051) 555-0199 during plant clinic hours (Tuesday & Thursday: 9:00 AM – 12:00 PM).
Sebastian County falls primarily within USDA Plant Hardiness Zone 7b / 8a. Local soil is characterized as Arkansas River Alluvial Silt Loam & Sandy Clay.
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.