LSU AgCenter Soil Testing & Plant Analysis Lab — combined lime + N/P/K/S nutrient source

v2.3 (2026-08-23) · Vieira, L.O., Tubaña, B., Padgett, G.B., Moseley, D., Gravois, K., Levy, R.J., Kerns, S.P. (Aug 2025). 'Fertilizer Recommendations for Field Crops in Louisiana: N-P-K-S' Pub 4004. LSU AgCenter. Lime: Parvej, M.R. (2024). 'Soil Acidity, Liming Materials and Lime Recommendations' Pub 3939. Soil sampling: Gonzalez Mejia, H. & Parvej (2024) Pub 3934.

State extension method Computes rates in-app Lime / pH

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Crops covered

AlfalfaBermudagrassBrassicasBrassicas — alluvial soilsBrassicas — upland soilsCloverCornCorn silageCottonFescueGrass hayMilletOatsOats, rye, ryegrass, ryegrass-clover mix, tall fescue, tall fescue-clover mix, wheat — alluvial soilsOats, rye, ryegrass, ryegrass-clover mix, tall fescue, tall fescue-clover mix, wheat — upland soilsPastureRiceRyeSorghumSorghum silageSoybeansSugarcaneWheat

Nutrient source for

Lime / pH source for

Frequently asked

What method does LSU AgCenter Soil Testing & Plant Analysis Lab — combined lime + N/P/K/S nutrient source use?

State extension method. Zone Forge computes this source's supported nutrient rates in-app and cites the published method. Its published lime method is computed in-app too.

Is this free to use?

Yes — Zone Forge's calculators are free and need no signup. This page shows the states and crops LSU AgCenter Soil Testing & Plant Analysis Lab — combined lime + N/P/K/S nutrient source covers so you can verify the source behind your recommendation.

Browse the full Coverage Explorer — every state, crop and source — or see the science →