Florida’s dynamic climate never ceases to surprise us. The historic drought we are under following extreme freezes not seen in decades has certainly made this spring an unusual one.
Water is key to nutrient uptake. It is also the limiting factor when it is absent since nutrient movement cannot happen from the soil to the root. Picture credit: Jonael Bosques, University of Florida.
We have had many concerned gardeners and farmers noticing the struggle of their crops and forage to survive and yield under the present environmental conditions.
Today we will discuss once again the roles of water and nutrients. We will do a deep dive in an interesting term called nutrient budgeting, and how this exercise can help you make decisions moving forward as it relates to growing crops, gardening and even forage production for your livestock.
What is nutrient budgeting and how does it affect us?
A simple explanation for nutrient budgeting is the action of keeping track of what nutrients are in your system, what your crop needs, and what leaves the field. It’s not about applying more fertilizer—it’s about applying the right amount at the right time.
In Florida, this matters even more. Our soils tend to be low in organic matter and highly permeable (water does not stay in the same place for long). This results in nutrients—especially nitrogen (N) and potassium (K) moving quickly below the root zone if we’re not careful. That’s not just a loss in efficiency; it’s also a loss to your bottom line and a potential environmental concern. Hence, we recommend that multiple small applications happen throughout the growing season taking into consideration the nature of your specific crop.
Step 1: Start with your soil (“nutrient account balance”)
You cannot manage what you cannot measure. Everything begins with knowing what you already have.
Analyzing soil nutrients through soil testing can help you determine the nutrient balance on your field. Picture credit: Jonael Bosques, University of Florida.
Routine soil testing is one of the most valuable tools available to Florida growers. Sampling at a consistent depth (typically around 6 inches) and dividing fields into representative zones gives you a clearer picture of variability across your operation. Soil test results will reveal information on pH and key nutrients like phosphorus, potassium, calcium, and magnesium.
Soil pH (acidity level) is especially important. If your pH is out of range, nutrients may be present in the soil but unavailable to the plant. As UF/IFAS guidance often emphasizes, keeping pH in an optimal range ensures nutrients can be taken up by crops.
Note that N was not included on the measured nutrients listed previously. Nitrogen is extremely hard to measure due to its capacity to vaporize. Because it moves so easily an estimated amount is determined based on the needs (crop demand), organic matter, and previous management.
Step 2: Match nutrients to crop demand
Once you know your “nutrient account balance”, the next step is aligning it with crop requirements.
UF/IFAS recommendations are designed specifically for Florida conditions and should be your starting point. These recommendations consider realistic yield goals and existing soil nutrient levels. But don’t stop there, remember to account for all nutrient sources.
That includes:
Previous fertilizer applications
Organic amendments (manure, compost)
Cover crops
Nutrients from irrigation water
These sources can contribute to meeting some, or even all of the nutrient requirements of the crop. But again, if you don’t know the nutritional content of manure, for example, and you apply it to your field, you may under or over apply essential nutrients, thus potentially affecting yields and your pocketbook.
Step 3: Track nutrient outputs (what leaves the field)
Remember, when you harvest crops from your field you are also harvesting nutrients. Picture credit: Jonael Bosques, University of Florida.
Here’s a piece that often gets underestimated: nutrients don’t just disappear; they leave with your harvest.
Every crop removes nutrients from the soil. If those nutrients are not replaced, soil fertility declines over time. This is why nutrient removal rates matter. Knowing how much nutrient leaves per acre allows you to close the loop and maintain long-term productivity.
How do you determine this? You can estimate the nutrients lost in harvest by monitoring the soil at the end of the growing season.
Step 4: Recognize losses beyond harvest
Not all nutrient losses are visible.
In Florida, leaching is one of the biggest challenges. Sandy soils allow water—and dissolved nutrients—to move quickly through the profile. Excess irrigation or heavy rainfall can push nutrients below the root zone before plants can use them.
Runoff can also carry nutrients away from the field, especially during intense storms.
This is where Best Management Practices (BMPs) come into play:
Proper irrigation scheduling
Split fertilizer applications
Cover cropping
Mulching to conserve moisture and nutrients
Each of these helps keep nutrients where they belong—in the root zone.
Water: the engine that moves nutrients
If nutrients are fuel, water is the delivery system. Lack of water will affect nutrient uptake by plants. Too much water can also affect the uptake of nutrients due to leaching.
Water is the center for plant survival. Picture credit: Jonael Bosques, University of Florida.
Plants do not take up nutrients in a dry form. Nutrients must first dissolve in soil water before they can move into the root system. As plants take up water, they simultaneously take in dissolved nutrients like nitrate and potassium.
This is why water management is inseparable from nutrient management.
Too much water is always a problem. When too much water moves through the soil, whether from over-irrigation or heavy rainfall (or three hurricanes in two months), it carries nutrients with it. In our sandy soils, that movement can happen quickly, making precise irrigation critical.
Consistent, efficient watering practices are essential because water directly influences nutrient availability, uptake, and loss.
Putting it all together
Nutrient budgeting is not a one-time task—it’s an ongoing process.
Here are some action items to consider when developing a nutrient budget:
Test your soil regularly: Every 1–2 years to track changes and guide decisions
Know your crop removal rates: Understand what nutrients leave with harvest
Split fertilizer applications: Especially for nitrogen and potassium
Manage irrigation carefully: Avoid overwatering that leads to leaching
Account for all nutrient sources: Including organic matter and irrigation water
Follow UF/IFAS recommendations: These are developed for Florida conditions
Nutrient budgeting doesn’t have to be complicated. Nutrient budgeting is a worthwhile exercise that will uncover the whereabouts of those nutrients you paid for when you purchased and applied the fertilizer for your field. Pay attention to the nutrient flow. This can make the difference between efficient production and wasted inputs. If you need further assistance on this topic, don’t hesitate to reach out to us at 863-773-2164 or drop by UF/IFAS Extension Hardee County located at 507 Civic Center Drive, Wauchula, FL 33873.
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