Coverage you can verify

Coverage Explorer

Every Zone Forge number traces to a land-grant extension publication. Browse by state, crop, or source — and see the exact method and citation behind each recommendation.

72 recommendation sources · 50 states · 251 crop families — 47 with their own published source, 3 neighbor-routed by design.

By state

AlabamaOwn sourceLime live
AlaskaOwn sourceLime live
ArizonaOwn sourceLime rarely needed
ArkansasOwn sourceLime live
CaliforniaOwn sourceLime live
ColoradoOwn sourceLime rarely needed
ConnecticutOwn sourceLime live
DelawareVerification in progressLime live
FloridaOwn sourceLime live
GeorgiaOwn sourceLime live
HawaiiOwn sourceLime live
IdahoOwn sourceComing soon
IllinoisOwn sourceLime live
IndianaOwn sourceLime live
IowaOwn sourceLime live
KansasOwn sourceLime live
KentuckyOwn sourceLime live
LouisianaOwn sourceLime live
MaineOwn sourceLime live
MarylandOwn sourceLime live
MassachusettsOwn sourceLime live
MichiganOwn sourceLime live
MinnesotaOwn sourceLime live
MississippiOwn sourceLime live
MissouriOwn sourceLime live
MontanaOwn sourceLime live
NebraskaOwn sourceLime live
NevadaNeighbor-routedLime rarely needed
New HampshireOwn sourceLime live
New JerseyOwn sourceLime live
New MexicoOwn sourceLime rarely needed
New YorkOwn sourceLime live
North CarolinaOwn sourceLime live
North DakotaOwn sourceLime live
OhioOwn sourceLime live
OklahomaOwn sourceLime live
OregonOwn sourceLime live
PennsylvaniaOwn sourceLime live
Rhode IslandNeighbor-routedLime live
South CarolinaOwn sourceLime live
South DakotaOwn sourceLime live
TennesseeOwn sourceLime live
TexasOwn sourceLime live
UtahOwn sourceLime rarely needed
VermontOwn sourceLime live
VirginiaOwn sourceLime live
WashingtonOwn sourceLime live
West VirginiaOwn sourceLime live
WisconsinOwn sourceLime live
WyomingNeighbor-routedLime rarely needed

By crop

Alfalfa · 39 states Alfalfa - New Seeding (UD ALS) · 1 state Alfalfa/Grass Mixed - New Seeding (UD AGS) · 1 state All vines (cucumber, gourd, melons, pumpkin, squash) · 2 states Annual or Italian Ryegrass - New Seeding (UD IRS) · 1 state Annual or Italian Ryegrass Forage (UD ARF) · 1 state Annual or Sweet Bromegrass Forage (UD ABF) · 1 state Apple establishment · 1 state Apples (new plantings only) · 1 state Apples, Pears · 1 state Asparagus (established bed) · 1 state Asparagus (new bed) · 1 state Asparagus - New Hybrids · 1 state Asparagus - Nonhybrid Strains · 1 state Asparagus establishment · 1 state Asparagus maintenance · 1 state Asparagus — Cutting Beds to Maintain · 1 state Bahia · 1 state Bahiagrass · 1 state Bahiagrass establishment · 1 state Bahiagrass grazed · 1 state Banana · 1 state Barley · 24 states Barley Forage (UD BAF) · 1 state Basil · 0 states Beet · 2 states Beets · 2 states Bermudagrass · 12 states Bermudagrass - New Seeding (UD BGS) · 1 state Big Bluestem - New Seeding (UD BBS) · 1 state Blueberries-Rabbiteye (commercial) · 2 states Blueberry · 2 states Blueberry establishment · 2 states Blueberry maintenance · 1 state Bluegrass · 6 states Brassica forage · 2 states Brassica/Grass Mix - New Seeding (UD BGS) · 1 state Brassicas · 1 state Brassicas — alluvial soils · 1 state Brassicas — upland soils · 1 state Broccoli · 3 states Broccoli (direct seeded and banded) · 1 state Broccoli brussels cauliflower · 1 state Broccoli, cauliflower (transplants only) · 1 state Bromegrass · 2 states Brussels sprouts · 2 states Buckwheat · 9 states Buffelgrass · 1 state Cabbage · 6 states Canola · 14 states Cantaloupe · 1 state Carrots · 4 states Cauliflower · 2 states Cauliflower (direct seeded and banded) · 1 state Celeriac · 0 states Celery · 3 states Cereal Rye Forage (UD RYF) · 1 state Chard · 0 states Cherry establishment · 1 state Chickpeas · 1 state Chicory/Grass Mix - New Seeding (UD CGS) · 1 state Chile peppers · 6 states Christmas trees · 2 states Citrus · 1 state Clover · 17 states Coffee · 1 state Collard · 1 state Collards · 0 states Commercial Blackberries · 1 state Commercial Blueberries · 1 state Conservation planting · 1 state Corn · 40 states Corn silage · 34 states Corn Silage (UD CSI) · 1 state Cotton · 14 states Cranberry establishment · 1 state Cucumbers · 5 states Dallisgrass · 1 state Dry beans · 12 states Eastern Gamagrass - New Seeding (UD EGS) · 1 state Eastern Gamagrass and Improved Bermudagrasses (maintenance, 5 tons/A) · 1 state Edamame (preplant incorporated row — no Total row printed) · 0 states Eggplant · 1 state Fescue · 10 states Field peas · 5 states Flax · 3 states Forage legumes · 14 states Forage Sorghum (UD FSF) · 1 state Gamagrass · 1 state Garlic · 0 states General forestry · 1 state Ginseng · 1 state Globe Artichoke · 0 states Gourds — direct-seeded · 0 states Grapes · 5 states Grass / forage · 13 states Grass hay · 30 states Grass/Legume Mix - New Seeding (UD GLS) · 1 state Green beans · 4 states Greens (Mustard, Turnip) — Turnip greens · 0 states Hemp · 1 state Hemp and Kenaf for Fiber (UD HMF) · 1 state Hemp and Kenaf for Fiber (UD KNF) · 1 state Hemp f or Seed (UD HMS) · 1 state Home Orchards · 1 state Hop · 1 state hops · 0 states Hops (UD HOP) · 1 state Horseradish · 0 states Hybrid Millets · 1 state Indian Grass - New Seeding (UD IGS) · 1 state Johnsongrass · 1 state Kale · 0 states Kenaf · 1 state Kentucky Bluegrass - New Seeding (UD KBS) · 1 state Kleingrass · 1 state Kohlrabi · 0 states Leaf Lettuce, Endive, or Escarole — Endive · 0 states Leaf Lettuce, Endive, or Escarole — Escarole · 0 states Leeks · 0 states Lentil, Chickpea and Pea · 3 states Lettuce · 6 states Lima · 1 state Lima beans · 2 states Limpograss · 1 state Little Bluestem - New Seeding (UD LBS) · 1 state Lovegrass · 1 state Lupin · 1 state Lupine · 2 states Macadamia · 1 state Malting Barley (UD MLT) · 1 state Microgreens · 0 states Millet · 12 states Mint oil · 1 state Muskmelon · 1 state Muskmelons and Mixed Melons · 0 states Mustard · 3 states Native warm season establishment · 1 state Oats · 28 states Oats, rye, ryegrass, ryegrass-clover mix, tall fescue, tall fescue-clover mix, wheat — alluvial soils · 1 state Oats, rye, ryegrass, ryegrass-clover mix, tall fescue, tall fescue-clover mix, wheat — upland soils · 1 state Okra · 2 states Onions · 4 states Orchardgrass · 3 states Orchardgrass - New Seeding (UD ORS) · 1 state Papaya · 1 state Parsley · 1 state Parsnips · 0 states Pasture · 18 states Pea, field, lentil and chickpea — Chickpea · 2 states Peaches · 2 states Peanuts · 9 states Pearl Millet (UD PMF) · 1 state Peas · 8 states Pecans · 2 states Perennial ryegrass · 1 state Perennial Ryegrass - New Seeding (UD PRS) · 1 state Pineapple · 1 state Plums · 1 state Popcorn · 3 states Potatoes · 16 states Prairiegrass · 1 state Pumpkin · 3 states Pumpkins and Winter Squash — Pumpkins · 1 state Pumpkins and Winter Squash — Winter squash · 0 states Radish · 3 states Radishes · 1 state Radishes, Rutabagas and Turnips — Rutabagas · 0 states Rape · 1 state Raspberry (established bed) · 1 state Raspberry (new bed) · 1 state Raspberry blackberry establishment · 1 state Raspberry blackberry maintenance · 1 state Raspberry establishment · 1 state Red Clover - New Seeding (UD RCS) · 1 state Reed canarygrass · 2 states Reed Canarygrass - New Seeding (UD RGS) · 1 state Rhubarb — Established Plantings · 0 states Rice · 5 states Roadside stand mix · 1 state Rutabaga, turnip · 2 states Rye · 16 states Safflower · 2 states Salad Mix · 0 states Scallion · 0 states Sericea · 1 state Sericea Lespedeza - New Seeding (UD SLS) · 1 state Shallot · 0 states Small Grain/Legume Forage (UD SLF) · 1 state Small grains · 12 states Smooth Bromegrass - New Seeding (UD SBS) · 1 state Sod turf establishment · 1 state Sorghum · 24 states Sorghum silage · 9 states Sorghum Silage (UD SOG) · 1 state Sorghum/Sudangrass Hybrid (UD SSF) · 1 state Soybeans · 35 states Spinach · 3 states Spring Oats (UD SOF) · 1 state Squash · 4 states Squash pumpkin · 1 state Stone Fruit · 1 state Strawberries · 1 state Strawberry · 2 states Strawberry (established bed) · 1 state Strawberry (new bed) · 1 state Strawberry establishment · 2 states Strawberry maintenance · 1 state Sudangrass · 3 states Sudangrass (UD SGF) · 1 state Sugar beets · 9 states Sugarcane · 3 states Summer Perennials Overseeded in Fall · 1 state Summer Squash · 0 states Sunflower · 15 states Sunflower (UD SFL) · 1 state Sweet corn · 9 states Sweetcorn · 1 state Sweetpotato · 1 state Swiss Chard · 0 states Switchgrass · 4 states Switchgrass - New Seeding (UD SGS) · 1 state Switchgrass biofuel · 1 state Table beet · 1 state Tall Fescue - New Seeding (UD TFS) · 1 state Taro · 1 state Teff · 1 state Teff (UD TFF) · 1 state Timothy - New Seeding (UD TMS) · 1 state Timothy, Smooth Bromegrass, Perennial Ryegrass (maintenance, 3 tons/A) · 2 states Tobacco · 8 states Tomatoes · 6 states Triticale · 5 states Triticale Forage (UD TRF) · 1 state Truck crops · 1 state Turnips · 1 state Vegetables (general) · 3 states Vetch · 1 state Vetch crown hairy · 1 state Watermelon · 4 states Watermelons — Irrigated · 1 state Waterways · 1 state Wheat · 39 states White Clover - New Seeding (UD WCS) · 1 state Wildlife Food Plots - Deer (UD WDR) · 1 state Wildlife Food Plots - Game Birds (UD WGB) · 1 state Wildlife Food Plots - Rabbits (UD WRB) · 1 state Wildlife Food Plots - Turkey (UD WTR) · 1 state Wildlife Food Plots - Waterfowl (UD WWF) · 1 state Winter Oat Forage (UD WOF) · 1 state Winter Wheat Forage (UD WWF) · 1 state

By source

Alabama — Auburn Nutrient Recommendations for Alabama Row Crops (May 2020)v1.3 (2026-08-23) · 1 stateRates Alaska — UAF Cooperative Extension Servicev1.5 (2026-08-23) · 1 stateRates Arizona — alkaline-soil region (lime rarely needed)v1.0 (2026-05-23) · 1 stateLime rarely needed Arizona — University of Arizona Cooperative Extension (Olsen-P calibration)v1.2 (2026-06-21) · 1 stateRates California — UC ANR / CDFA-FREP / UC Davis Nutrient Management (Olsen-P calibration + commodity manuals)v1.2 (2026-06-10) · 1 stateRates Coastal Plain Adams-Evans lime method (University of Delaware calibration)v1.2 (2026-06-21) · 5 statesLime rates Colorado — alkaline-soil region (lime rarely needed)v1.0 (2026-05-23) · 1 stateLime rarely needed Colorado — CSU Extension Crop Series Soil fact sheets (Olsen-P + Mehlich-3 dual calibration)v1.2 (2026-08-23) · 1 stateRates Connecticut — UConn Soil Nutrient Analysis Laboratory (Modified Morgan extractant)v1.2 (2026-06-11) · 1 stateRates Cornell NMSP Nutrient Guidelines for Commercial Vegetable Production (2026)v1.0 (2026-08-24) · Alternate guide — 1 stateRates Delaware — UD Cooperative Extension Soil Testing Program (Mehlich-3 / UD-FIV)v1.6 (2026-09-23) · 1 stateRates EM 9140 — Green Pea Nutrient Management for the Inland Northwest, East of the Cascadesv1.0 (2026-08-23) · Alternate guide — 2 statesRates EM 9224 — Nutrient Management for Pastures: Western Oregon and Western Washingtonv1.0 (2026-08-23) · Alternate guide — 2 statesRates Georgia — UGA Soil Test Handbook (SB 62) + UGFertex Nutrient Recommendationsv1.4 (2026-08-24) · 1 stateRates Great Plains Canola Production Handbook (MF2734)v1.0 (2026-08-23) · Alternate guide — 2 statesRates Hawaii — UH-Manoa CTAHR Agricultural Diagnostic Service Centerv1.2 (2026-06-11) · 1 stateRates Illinois Agronomy Handbook — Chapter 8 (Managing Soil pH and Crop Nutrients)v2.1 (2026-06-10) · 1 stateRates Iowa State University Extension — PM 1688: A General Guide for Crop Nutrient and Limestone Recommendations in Iowav1.3 (2026-08-23) · 1 stateRates Kansas State University — Soil Test Interpretations & Fertilizer Recommendations (MF2586)v2.3 (2026-09-18) · 1 stateRates LSU AgCenter Soil Testing & Plant Analysis Lab — combined lime + N/P/K/S nutrient sourcev2.3 (2026-08-23) · 1 stateRates Mid-Atlantic Commercial Vegetable Production Recommendations 2026/2027v1.0 (2026-08-23) · Alternate guide — 6 statesRates Mississippi State University — Nutrient Management Guidelines (Lancaster extractant)v2.2 (2026-08-23) · 1 stateRates Montana State University Extension — EB0161 Fertilizer Guidelines for Montana Cropsv1.2 (2026-08-23) · 1 stateRates Montana State University — Soil acidification rule (1.5 × ΔpH)v1.0 (2026-05-23) · 1 stateLime rates NCDA&CS Agronomic Division — Mehlich-3 + Humic-Matter Lime + Orange Book Crop Fertilizationv2.4 (2026-08-23) · 1 stateRates NDSU SF-882 — North Dakota Fertilizer Recommendation Tables and Equations + simple-rule limev1.5 (2026-08-23) · 1 stateRates Nevada — alkaline-soil region (lime not needed)v1.0 (2026-05-23) · 1 stateLime rarely needed Nevada — UNR Cooperative Extension (lab-referral framework + Lovelock alfalfa convention)v1.1 (2026-06-10) · 1 stateRates New England Vegetable Management Guide 2025-2026v1.1 (2026-08-23) · Alternate guide — 5 statesRates New Hampshire — UNH Cooperative Extension Soil Testing Servicev1.3 (2026-06-21) · 1 stateRates New Jersey — Rutgers Cooperative Extension / NJAESv1.2 (2026-06-10) · 1 stateRates New Mexico — alkaline-soil region (lime rarely needed)v1.0 (2026-05-23) · 1 stateLime rarely needed New Mexico — NMSU Cooperative Extension Service (Olsen-P calibration, calcareous-soil framework)v1.4 (2026-06-21) · 1 stateRates New York — Cornell NMSP / CNAL — Agro-One (combined lime + nutrient)v2.1 (2026-06-10) · 1 stateRates Oklahoma — OSU SWFAL (PSS-2225) combined lime + nutrient sourcev2.1 (2026-06-10) · 1 stateRates Oregon — OSU Extension nutrient guides (W. Oregon EM-8963 + Eastern dryland FG-80/82/83/84 series)v1.3 (2026-06-21) · 1 stateRates OSU Specialty Crop Nutrient Guides — Hops and Hazelnutsv1.0 (2026-08-23) · Alternate guide — 1 stateRates OSU Updated Lime Requirement Recommendations for Oregon (EM-9585, October 2025)v1.0 (2026-05-23) · 1 stateLime rates Penn State Agronomy Guidev1.4 (2026-08-23) · 1 stateRates PNW 615 — Nutrient Management for Field Corn Silage and Grain in the Inland Pacific Northwestv1.0 (2026-08-23) · Alternate guide — 3 statesRates Rhode Island — URI Cooperative Extension referral pathway → UMass Soil & Plant Nutrient Testing Laboratoryv1.0 (2026-05-27) · 1 stateRates SDSU — Fertilizer Recommendations Guide (P-00039)v1.0 (2026-05-23) · 1 stateLime rates South Carolina — Clemson Cooperative Extension Nutrient Recommendations (LGP 1151 + 2024 Corn Production Guide)v1.1 (2026-08-23) · 1 stateRates South Dakota - SDSU Extension Fertilizer Recommendations (EC750 lineage + S-0003-23 Corn / S-0004-22 Soybean / S-0005-11 Wheat)v1.3 (2026-08-23) · 1 stateRates Texas A&M AgriLife — Mehlich-3 sufficiency + High Plains research calibrationv1.1 (2026-08-23) · 1 stateRates Texas A&M AgriLife — pH × Texture lookup (no buffer)v1.0 (2026-05-23) · 1 stateLime rates Tri-State Fertilizer Recommendations (2020)v1.4 (2026-08-23) · 3 statesRates UConn Soil Nutrient Analysis Laboratory — SMP / Sikora bufferv1.0 (2026-05-23) · 2 statesLime rates UF/IFAS — Standardized Fertilization Recommendations for Agronomic Cropsv2.4 (2026-08-23) · 1 stateRates UMass Soil & Plant Nutrient Testing Lab — Modified Morgan + SMP/Sikora bufferv2.2 (2026-08-21) · 1 stateRates UNH Soil Testing Service — Mehlich Lime Buffer pHv1.0 (2026-05-23) · 1 stateLime rates University of Arkansas — pH+Ca lime + Mehlich-3 nutrient recsv1.2 (2026-06-04) · 1 stateRates University of Georgia — Equilibrium Lime Buffer Capacity (LBCEq)v1.0 (2026-05-23) · 1 stateLime rates University of Idaho — Northern ID (dryland Palouse) + Southern ID (irrigated Snake River Plain) Fertilizer Guidesv2.3 (2026-08-23) · 1 stateRatesLime coming soon University of Kentucky — AGR-1 Lime and Fertilizer Recommendations (2025-2026)v2.3 (2026-08-23) · 1 stateRates University of Maine Soil Testing Handbook — Modified Morgan + Mehlich Buffer (3rd Revised Edition 2026)v1.1 (2026-08-23) · 1 stateRates University of Maryland — Texture × Province lime (SFM-5) + Maryland Nutrient Management Manual FIV-based N/P/K (combined source)v2.2 (2026-08-23) · 1 stateRates University of Minnesota Extension — Sikora Buffer (lime) + Dual-extractant MRTN (nutrients)v2.2 (2026-08-23) · 1 stateRates University of Missouri — Soil Test Interpretations & Recommendations Handbook (Buchholz et al., 5/2004) + Woodruff Buffer/ENM limev2.1 (2026-06-10) · 1 stateRates University of Nebraska — Lime Use for Soil Acidity Management (G1504)v1.0 (2026-05-23) · 1 stateLime rates University of Tennessee — Nutrient Recommendations (M1 default + M3 dual calibration)v1.3 (2026-08-23) · 1 stateRates University of Vermont — Reactive Aluminum + Modified Morgan (UVM AETL)v2.2 (2026-06-10) · 1 stateRates UNL EC117 / EC155 / G859 — Nebraska nutrient recommendations (lime in separate nebraska_g1504)v1.3.1 (2026-08-23) · 1 stateRates UT Soil, Plant and Pest Center — Adams-Evans family buffer (TN)v1.0 (2026-05-23) · 1 stateLime rates Utah — alkaline-soil region (lime not needed)v1.0 (2026-05-23) · 1 stateLime rarely needed Utah — USU Cooperative Extension (Olsen-P + NaHCO3-K calibration)v1.3 (2026-06-21) · 1 stateRates UW Madison Extension A2809 — Nutrient Application Guidelines for Field, Vegetable, and Fruit Crops in Wisconsinv2.5 (2026-09-15) · 1 stateRates Virginia Tech Soil Testing Laboratory — Mehlich-1 + Modified Mehlich Buffer (combined source)v2.5 (2026-08-23) · 1 stateRates WSU Extension — East/West Cascade nutrient + Inland NW lime (combined source)v2.3 (2026-06-10) · 1 stateRates WVU Extension — Mehlich-3 ICP + LR Mehlich Buffer (Crop Fertilization Recommendations)v2.2 (2026-08-23) · 1 stateRates Wyoming — alkaline-soil region (lime effectively not needed)v1.0 (2026-05-23) · 1 stateLime rarely needed Wyoming — UW Extension (lab-referral framework + Bighorn Basin sugarbeet/dry-bean overrides)v1.0 (2026-05-27) · 1 stateRates