This tool is intended to help vegetable growers select the best combination of inputs based on a soil test. If you have not completed a soil test, please visit The Soil Testing Laboratory for instructions and forms. Please note that all fields are required in order for the tool to function properly.
We know that many mixed vegetable operations grow a large diversity of crops. Since different vegetables have very different nutrient needs, we recommend choosing at least your top three most important crops and figuring out specific nutrient recommendations for each crop.
Please select the crop you plan to grow, and indicate the total area you plan to plant with this crop with the length of the planting area and the width of the planting area in feet. If you do not see your crop on the list, choose something of a similar size and type for an approximate recommendation (e.g. if you're growing a ~50 day leafy green crop, you could select spinach).
Use the values from your soil test to fill out this section so that we can make a recommendation based on the specific needs and characteristics of your soil. Phosphorus level: your soil test might report both the Olsen and the Bray test. If your soil pH is above 7.4, please use the Olsen value. If it is 7.4 or less, please use the Bray value. If only one is listed, use whichever you have.
Phosphorus level
Do you have a nitrogen credit from a cover crop, previous crop, or previous input? If so, please estimate your N credit in pounds per acre. If you do not know, enter 0.
Choose two sources of fertilty that you plan to use. Typically a single product will not provide the right balance of nitrogen, phosphorus, and potassium to meet your crop needs, and so you will need to mix at least two products to achieve the right balance. The options in the drop-down menus below are based on average values, but we always advise that you test inputs like compost and manure before applying large volumes since nutrient values can vary significantly from batch to batch.
NOTE: Fertility sources marked with an asterisk (*) are things that can usually be used in an organic system, but always check with your certifier before using a product if you are a certified organic farmer.
If your results from above show that you do not need any phosphorus, select at least one input with 0% phosphorus. Likewise if you do not need any nitrogen, select at least one input with 0% nitrogen, and if you do not need any potassium, choose at least one input with 0% potassium.
Select a balanced fertility product to start:
Select a supplemental product to balance your N-P-K needs (If your N needs are higher than your P needs, select a nitrogen rich supplemental product):
*This tool was primarily built to balance N and P needs, so K sources are limited in this list. The final step in the tool will provide you with a recommendation to supply potassium sulfate to meet any additional K needs not met by the two products you select in this step.
