Question: If 4 ton/acre of alfalfa is removed, how much potash is required to replenish the stand?
Answer: Alfalfa is a big user of potassium. For every 1 ton of alfalfa, 60 lbs of K2O per acre are removed. This is equivalent to 100 lbs of potash (0-0-60). Your alfalfa yield of 4 ton/acre would need 400 lbs/acre of potash to meet crop removal rates. For alfalfa, it is recommended that the potash be applied at least two times per growing season. Ideally, apply the potash after the first and last cuttings of the season. The nutrient removal rates are book values to give us a general idea; you should also pull soil tests every two years to monitor your nutrient levels and pH. Also, keep in mind that alfalfa is highly responsive to boron as well.Alfalfa Nutrient Removal Rates
| Crop | Unit | P2O5 | K2O | Mg | Ca | S |
| Alfalfa | Ton | 15.0 | 60.0 | 5.0 | 28.0 | 5.0 |
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| Yield Goal | P2O5 | MAP | DAP |
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| Alfalfa | 4 | 60 | 115 | 130 |
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| K2O | Potash |
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| 240 | 400 | lbs per acre for 4 ton | ||
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This blog is provided as an interactive way for you to have your questions answered by our Farm Journal Agronomists. E-mail your nitrogen, soil fertility, soil density, planter set up, scouting, and other questions to TestPlots@FarmJournal.com.
