50-State Agricultural Fertilizer & Nutrient Laws
State-by-state Department of Agriculture commercial custom fertilizer applicator certifications, USDA NRCS 590 Nutrient Management Plans (NMP), phosphorus index runoff limits, frozen/snow-covered ground application bans, and surface water setback buffer zones.
| State | Governing Department of Agriculture / Natural Resources | Commercial Fertilizer Applicator License | Frozen / Snow-Covered Ground Application Ban | Surface Water & Potable Well Setback Buffer |
|---|---|---|---|---|
| Alabama | AL Department of Agriculture & Industries (ADAI) | Commercial Custom Applicator Permit | Restricted on saturated soils | 25 ft to surface water / 50 ft to wells |
| Alaska | Alaska DEC Division of Environmental Health | Pesticide / Fertilizer Applicator Permit | Prohibited during sub-zero freezing | 50 ft salmon stream protection buffer |
| Arizona | Arizona Department of Agriculture (AZDA) | Agricultural Commercial Applicator License | Year-round permitted under irrigation | 20 ft canal and irrigation ditch setback |
| Arkansas | Arkansas Department of Agriculture Plant Board | Certified Commercial Applicator (Category 1) | Banned on flooded rice fields | 25 ft natural stream setback |
| California | CDFA & Regional Water Quality Control Boards | CDFA Fertilizer Research & Qualified Applicator | Strict Nitrogen Management Plan (ILRP) | 35 ft setback (SWRCB Ag Order) |
| Colorado | Colorado Department of Agriculture (CDA) | Commercial Applicator (Ag Category 101) | Restricted on frozen slope surfaces | 25 ft perennial stream buffer |
| Connecticut | CT Department of Agriculture / DEEP | Commercial Applicator Certification | Banned Dec 1 to March 15 (Frozen Soil) | 25 ft wetland and lake buffer |
| Delaware | Delaware Department of Agriculture (DDA) | Mandatory Certified Nutrient Consultant | Banned Dec 15 to Feb 15 (Winter Ban) | 25 ft watercourse / 100 ft public well |
| Florida | FDACS Division of Agricultural Environmental Services | FDACS Ag Non-Point Source BMP License | Monitored under Basin Management Plans | 15 ft minimum buffer / 25 ft to karst |
| Georgia | Georgia Department of Agriculture (GDA) | Commercial Fertilizer Distributor & Applicator | Restricted during heavy rain warnings | 25 ft stream buffer |
| Hawaii | Hawaii Department of Agriculture (HDOA) | Commercial Agricultural Applicator License | Prohibited during flash flood watches | 30 ft coastal watershed buffer |
| Idaho | ISDA Division of Agricultural Resources | Professional Applicator (Ag Category) | Prohibited on snow > 1 inch | 25 ft canal and river setback |
| Illinois | Illinois Department of Agriculture (IDOA) | Commercial Custom Applicator License | Restricted on frozen soil > 5% slope | 20 ft stream buffer / 50 ft to potable well |
| Indiana | Office of Indiana State Chemist (OISC) | Category 14 Commercial Fertilizer Applicator | Banned on frozen / snow-covered ground | 20 ft surface water / 50 ft drinking well |
| Iowa | IDALS Fertilizer Bureau | Commercial Applicator (Category 1) | Prohibited on snow-covered slopes | 25 ft watercourse / 100 ft sinkhole |
| Kansas | Kansas Department of Agriculture (KDA) | Commercial Applicator (Ag Plant 1A) | Restricted on frozen runoff slopes | 25 ft perennial stream setback |
| Kentucky | Kentucky Department of Agriculture (KDA) | Commercial Applicator Certification | Banned on frozen slopes > 6% | 25 ft creek / 50 ft to sinkhole/karst |
| Louisiana | LDAF Department of Agriculture & Forestry | Commercial Agricultural Applicator License | Restricted during storm surge flooding | 25 ft bayou and canal buffer |
| Maine | Maine Department of Agriculture, Conservation & Forestry | Commercial Master Applicator (Ag) | Banned Dec 1 to March 15 (Frozen Soil) | 25 ft lake / 100 ft private well |
| Maryland | Maryland Department of Agriculture (MDA) | Mandatory Certified Nutrient Applicator | Banned Nov 15 to March 1 (Winter Ban) | 35 ft vegetated buffer (Chesapeake Bay) |
| Massachusetts | MDAR Division of Crop and Pest Services | Commercial Certification (Category 38) | Banned Dec 1 to March 1 (Winter Ban) | 25 ft to water / 50 ft to drinking supply |
| Michigan | MDARD Pesticide & Plant Pest Management | Commercial Applicator (Ag Category 1A) | Banned on frozen soil in Western Lake Erie Basin | 25 ft Great Lakes tributary setback |
| Minnesota | Minnesota Department of Agriculture (MDA) | Commercial Applicator License (Ag Plant) | Banned fall/winter nitrogen on vulnerable groundwater | 25 ft perennial water / 50 ft to well |
| Mississippi | MDAC Bureau of Plant Industry | Commercial Custom Applicator Permit | Restricted on saturated delta soils | 25 ft river and oxbow buffer |
| Missouri | Missouri Department of Agriculture (MDA) | Commercial Applicator (Category 1A) | Restricted on frozen slope surfaces | 25 ft stream buffer / 50 ft to sinkhole |
| Montana | Montana Department of Agriculture (MDA) | Commercial Applicator (Ag Category 30) | Prohibited during sub-zero deep freezing | 25 ft river and canal setback |
| Nebraska | Nebraska Department of Agriculture (NDA) | Commercial Applicator (Ag Category 01) | Restricted on frozen ground near NRD water | 25 ft stream buffer / 50 ft to well |
| Nevada | Nevada Department of Agriculture (NDA) | Commercial Applicator License (Ag) | Year-round permitted under irrigation | 25 ft river and ditch buffer |
| New Hampshire | NHDAMF Division of Pesticide Control | Commercial Applicator Certification | Banned Dec 1 to March 15 (Winter Ban) | 25 ft wetland and lake buffer |
| New Jersey | NJDA Division of Agricultural & Natural Resources | Certified Fertilizer Applicator (Ag/Turf) | Banned Dec 1 to March 1 (Winter Ban) | 25 ft to water / 10 ft with deflector |
| New Mexico | NMDA Department of Agriculture | Commercial Applicator (Ag Category 1A) | Restricted on frozen ditch banks | 20 ft acequia and canal buffer |
| New York | NYS DEC / AGM Division of Plant Industry | Commercial Applicator (Ag Category 1A) | Banned Dec 1 to March 15 (CAFO / Ag Rules) | 25 ft watercourse / 100 ft to well |
| North Carolina | NCDA&CS Agronomic Services Division | Commercial Applicator (Ag Category 1) | Restricted in Neuse / Tar-Pamlico basins | 30 ft riparian buffer zone |
| North Dakota | North Dakota Department of Agriculture (NDDA) | Commercial Custom Applicator (Ag Plant) | Prohibited on snow-covered frozen slopes | 25 ft prairie pothole / river setback |
| Ohio | Ohio Department of Agriculture (ODA) | Mandatory Agricultural Fertilizer Applicator (Cat 15P) | Banned on frozen/snow ground in Western Lake Erie Basin | 20 ft water buffer / 50 ft to wellhead |
| Oklahoma | ODAFF Consumer Protection Services | Commercial Applicator (Ag Category 1A) | Restricted in scenic river watersheds | 25 ft creek / 50 ft to water well |
| Oregon | ODA Fertilizer Program & Natural Resources | Commercial Applicator License (Ag) | Prohibited during winter flood alerts | 25 ft fish-bearing stream buffer |
| Pennsylvania | PDA Bureau of Plant Industry / State Conservation | Commercial Applicator & Nutrient Specialist | Banned Dec 15 to Feb 28 (Winter Ban) | 35 ft vegetated buffer / 100 ft well |
| Rhode Island | RIDEM Division of Agriculture | Commercial Applicator Certification | Banned Dec 1 to March 15 (Frozen Soil) | 25 ft pond and wetland setback |
| South Carolina | Clemson University DPR / SC Dept of Ag | Commercial Applicator (Ag Category 1A) | Restricted during flash flood events | 25 ft stream and canal buffer |
| South Dakota | SD DANR Division of Ag & Environmental Services | Commercial Applicator (Ag Category 1A) | Prohibited on frozen slopes > 4% | 25 ft river and wetland buffer |
| Tennessee | Tennessee Department of Agriculture (TDA) | Commercial Applicator (Category 1) | Restricted on frozen ground | 25 ft stream buffer / 50 ft to sinkhole |
| Texas | Texas Department of Agriculture (TDA) | Commercial Applicator (Ag Category 1A) | Restricted near playa lakes / Edwards Aquifer | 25 ft surface water / 50 ft to well |
| Utah | UDAF Plant Industry Division | Commercial Applicator (Ag Category 1A) | Restricted on frozen slope surfaces | 25 ft stream and canal setback |
| Vermont | VAAFM Agency of Agriculture, Food & Markets | Commercial Applicator Certification | Banned Dec 15 to April 1 (Winter Ban) | 25 ft perennial stream / 100 ft well |
| Virginia | VDACS Office of Pesticide Services / DCR | Certified Commercial Applicator (Category 1) | Banned Dec 1 to Feb 15 in Chesapeake Bay | 35 ft riparian buffer zone |
| Washington | WSDA Pesticide Management Division | Commercial Applicator License (Ag) | Prohibited during saturated winter runoff | 25 ft salmon stream buffer |
| West Virginia | WV Department of Agriculture (WVDA) | Commercial Applicator (Category 1) | Restricted on frozen mountain slopes | 25 ft creek / 50 ft to water well |
| Wisconsin | DATCP Division of Agricultural Resource Management | Commercial Applicator (Category 1.1 Field Crops) | Banned on frozen ground in winter (NR 151 Rules) | 20 ft perennial stream / 50 ft well |
| Wyoming | Wyoming Department of Agriculture (WDA) | Commercial Applicator (Ag Category 1) | Prohibited on snow > 2 inches | 25 ft river and ditch setback |