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 · 201 crop families — 47 states calibrated, 3 neighbor-routed by design.

By state

AlabamaCalibratedLime calibrated
AlaskaCalibratedLime calibrated
ArizonaCalibratedLime rarely needed
ArkansasCalibratedLime calibrated
CaliforniaCalibratedLime calibrated
ColoradoCalibratedLime rarely needed
ConnecticutCalibratedLime calibrated
DelawareCalibratedLime calibrated
FloridaCalibratedLime calibrated
GeorgiaCalibratedLime calibrated
HawaiiCalibratedLime calibrated
IdahoCalibratedLime calibrated
IllinoisCalibratedLime calibrated
IndianaCalibratedLime calibrated
IowaCalibratedLime calibrated
KansasCalibratedLime calibrated
KentuckyCalibratedLime calibrated
LouisianaCalibratedLime calibrated
MaineCalibratedLime calibrated
MarylandCalibratedLime calibrated
MassachusettsCalibratedLime calibrated
MichiganCalibratedLime calibrated
MinnesotaCalibratedLime calibrated
MississippiCalibratedLime calibrated
MissouriCalibratedLime calibrated
MontanaCalibratedLime calibrated
NebraskaCalibratedLime calibrated
NevadaNeighbor-routedLime rarely needed
New HampshireCalibratedLime calibrated
New JerseyCalibratedLime calibrated
New MexicoCalibratedLime rarely needed
New YorkCalibratedLime calibrated
North CarolinaCalibratedLime calibrated
North DakotaCalibratedLime calibrated
OhioCalibratedLime calibrated
OklahomaCalibratedLime calibrated
OregonCalibratedLime calibrated
PennsylvaniaCalibratedLime calibrated
Rhode IslandNeighbor-routedLime calibrated
South CarolinaCalibratedLime calibrated
South DakotaCalibratedLime calibrated
TennesseeCalibratedLime calibrated
TexasCalibratedLime calibrated
UtahCalibratedLime rarely needed
VermontCalibratedLime calibrated
VirginiaCalibratedLime calibrated
WashingtonCalibratedLime calibrated
West VirginiaCalibratedLime calibrated
WisconsinCalibratedLime calibrated
WyomingNeighbor-routedLime rarely needed

By crop

Alfalfa · 38 states All vines (cucumber, gourd, melons, pumpkin, squash) · 2 states 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 Basil · 0 states Beet · 2 states Beets · 2 states Bermudagrass · 12 states Blueberries-Rabbiteye (commercial) · 2 states Blueberry · 2 states Blueberry establishment · 2 states Blueberry maintenance · 1 state Bluegrass · 5 states Brassica forage · 2 states 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 Chard · 0 states Cherry establishment · 1 state Chickpeas · 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 · 41 states Corn silage · 33 states Cotton · 15 states Cranberry establishment · 1 state Cucumbers · 5 states Dallisgrass · 1 state Dry beans · 12 states 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 · 9 states Field peas · 5 states Flax · 3 states Forage legumes · 14 states 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 Green beans · 4 states Greens (Mustard, Turnip) — Turnip greens · 0 states Hemp · 1 state Home Orchards · 1 state Hop · 1 state hops · 0 states Horseradish · 0 states Hybrid Millets · 1 state Johnsongrass · 1 state Kale · 0 states Kenaf · 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 · 3 states Limpograss · 1 state Lovegrass · 1 state Lupin · 1 state Lupine · 2 states Macadamia · 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 · 27 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 And Reed Canary Grass (maintenance, 4 tons/A) · 2 states 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 Peas · 8 states Pecans · 2 states Pineapple · 1 state Plums · 1 state Popcorn · 3 states Potatoes · 15 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 Reed canarygrass · 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 Shallot · 0 states Small grains · 12 states Sod turf establishment · 1 state Sorghum · 25 states Sorghum silage · 8 states Soybeans · 35 states Spinach · 3 states 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 Sugar beets · 8 states Sugarcane · 3 states Summer Perennials Overseeded in Fall · 1 state Summer Squash · 0 states Sunflower · 14 states Sweet corn · 9 states Sweetcorn · 1 state Sweetpotato · 1 state Swiss Chard · 0 states Switchgrass · 3 states Switchgrass biofuel · 1 state Table beet · 1 state Taro · 1 state Teff · 1 state Timothy, Smooth Bromegrass, Perennial Ryegrass (maintenance, 3 tons/A) · 2 states Tobacco · 8 states Tomatoes · 6 states Triticale · 5 states 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

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)v1.5 (2026-08-24) · 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)v2.1 (2026-06-21) · 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 stateRates 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 Wisconsinv2.2 (2026-08-23) · 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