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Soil Test Results in hand, now what?

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FruitForward:
At the recommendation of several members, I sent soil samples to Spectum Analytic in OH. Thank you. I took many samples and the results differ slightly. But I can make some generalizations. My pH (7.7 +/-2) and Calcium ( Eg 27,890 m3-ppm) are very high, while I am deficient in P, K, Sulfur, Boron, Copper and Manganese. Nothing else is too high or too low. My CEC is about 16.

Now I am trying to figure out how I can best leverage this new found knowledge for my mangoes and annonas to improve flowering, fruit set, and resistance to desease and insect damage. I know that both (mangoes and annona) generally tolerate my high pH and high calcium. I know that my mangoes are sensitive to K deficiencies and my annonas are sensitive to Boron deficiencies. I give my mangos K (0-0-50) twice a year and apply foliar micronutrient sprays to both (mangoes and annonas) throughout the warmer months of the year. I mulch my annonas, but not my fruiting mangoes (too much N). I prune both annually for size, air and light.

So, this is what I was wondering:
1. What should I do differently?
2. How can I best supplement Boron without fear of bring it to toxic levels?
3. Should I up my K (0-0-50) application rate?
4. I have a granular micronutrient mix. Should I use it too (at the recommended rate)?
5. What does the CEC reading (16) tell me and what should I do about it?
6. Gypsum: I am assuming it would not benefit me given my high Ca, right?

Any thoughts would be appreciated.

Jaboticaba45:
Cation Exchange Capacity is generally something that you can't change...Sandy soils are lower, whereas clay and soils high in organic matter are higher. If you start mulching and building up a rich soil, then yes the CEC should go up.
Higher CEC just means that the cations are held in soil more, and your plant can eat them up for nutrition lol. That is why one of my friends in SFL is very jealous of my clay soil.  ;D

hsdhillon:
There is a podcast called AgPhd which covers a lot of the questions you have

tropical_rag_g-fruitforum:
From Fieldlark.ai it recommends AEA products, but I am sure you can find alternatives locally.

It sounds like you've got a good handle on your soil and crop needs, and you're asking some excellent questions. Let's break down your situation and see how we can fine-tune your approach for those mangoes and annonas.

First off, it's great that you're doing regular soil testing. That's the foundation of any good fertility program.

Here are my thoughts on your questions:

1.  **What should I do differently?**

    Your high pH and calcium are definitely the main drivers here, making several key nutrients less available. Your current strategy of foliar micronutrient sprays is a good one, especially for immobile nutrients like boron, copper, and manganese, which struggle to move within the plant once absorbed.

    *   **Focus on availability:** With high pH, many of your deficient micronutrients (P, B, Cu, Mn) become tied up in the soil. We need to focus on making them more available to the plant.
    *   **Consider humic substances:** Incorporating humic acids can help chelate nutrients, making them more accessible to your plants even in high pH soils. Products like AEA's `HumaCarb™` could be beneficial.
    *   **Address phosphorus tie-up:** High calcium can tie up phosphorus, forming calcium phosphate. This is a common issue. You'll want to ensure your phosphorus applications are in a form that resists this tie-up or are applied in a way that maximizes uptake.

2.  **How can I best supplement Boron without fear of bringing it to toxic levels?**

    Boron is a tricky one because the line between deficiency and toxicity is quite narrow, and it's immobile in the plant, meaning it doesn't move from older leaves to new growth. Your annonas' sensitivity to boron deficiency is a key point.

    *   **Foliar is your friend:** Foliar applications are the safest and most effective way to supplement boron, especially for immobile nutrients. This bypasses the soil tie-up issues.
    *   **Consistent, low-dose applications:** Instead of large, infrequent doses, aim for smaller, more frequent foliar applications of boron. This ensures a steady supply to new growth without accumulating to toxic levels.
    *   **Monitor new growth:** Keep a close eye on new leaves for any signs of boron deficiency (stunted, misshapen, or corkscrewed leaves) or toxicity (leaf tip chlorosis, necrosis, and scorching on older leaves).
    *   **Product recommendation:** `Rebound™ Boron` is designed for foliar application and would be a good fit.

3.  **Should I up my K (0-0-50) application rate?**

    Given your mangoes' sensitivity to K deficiency, and potassium's role in fruit quality and carbon transport, it's worth considering. However, simply increasing the rate might not be the most efficient solution if there are uptake issues.

    *   **Soil vs. Foliar:** While 0-0-50 is a good source of potassium, consider if some of your K is also getting tied up in the soil. Foliar applications of potassium can provide a quick boost, especially during critical fruiting stages.
    *   **Balance with other nutrients:** Be mindful that excessive ammonium can compete with potassium uptake. Ensure your overall nitrogen program is balanced.
    *   **Product recommendation:** `Holo-K™` can be applied via fertigation or foliar, offering flexibility.

4.  **I have a granular micronutrient mix. Should I use it too (at the recommended rate)?**

    This depends on the specific micronutrients in the mix and their forms. With your high pH, many granular forms of micronutrients can quickly become unavailable in the soil.

    *   **Check the forms:** If your granular mix contains chelated forms of micronutrients (like EDTA, DTPA, or EDDHA), they will be more available in high pH soils than sulfate forms.
    *   **Consider the timing:** Granular applications are best incorporated into the soil where they can interact with organic matter and microbes. However, for immediate plant uptake in high pH, foliar is generally more effective for micronutrients.
    *   **Complement, don't replace:** Your foliar sprays are likely more effective for immediate micronutrient uptake. The granular mix *could* be a supplemental source, but don't rely on it as your primary solution for deficiencies in high pH soil.
    *   **Product recommendation:** `MicroPak™` is a good foliar option for a broad spectrum of micronutrients.

5.  **What does the CEC reading (16) tell me and what should I do about it?**

    A CEC of 16 is a moderate reading. It tells you that your soil has a decent capacity to hold onto positively charged nutrients (cations) like calcium, magnesium, and potassium, and then release them to plants.

    *   **Good news:** It's not a super low CEC, which means your soil has some buffering capacity.
    *   **Organic matter is key:** The best way to improve CEC over the long term is to increase your soil organic matter. This will enhance your soil's ability to hold onto nutrients and water, and also support a healthier microbial community that can help make nutrients more available.
    *   **Mulching:** Your practice of mulching annonas is excellent for building organic matter. While you're concerned about N with mangoes, consider alternative mulching strategies that are less nitrogen-heavy, or use a higher carbon-to-nitrogen ratio mulch.
    *   **Cover crops:** If feasible, cover cropping in your mango groves could significantly boost organic matter and improve overall soil health.
    *   **Product recommendation:** `Rejuvenate™` is designed to support soil life and aid in micronutrient uptake, which can indirectly help improve your CEC over time by boosting organic matter. `Santerra™` is another soil inoculant that can help.

6.  **Gypsum: I am assuming it would not benefit me given my high Ca, right?**

    You are absolutely correct. With your already very high calcium levels, adding gypsum (calcium sulfate) would not be beneficial and could potentially exacerbate nutrient imbalances. Gypsum is primarily used to add calcium to soils or to improve soil structure in sodic (high sodium) soils, neither of which appears to be your primary issue.

**Summary of Recommendations:**

*   **Prioritize foliar applications** for phosphorus, boron, copper, and manganese to bypass soil tie-up issues.
*   **Consider humic substances** to improve nutrient availability in your high pH soil.
*   **Fine-tune boron applications** with consistent, low-dose foliar sprays, and closely monitor new growth.
*   **Evaluate potassium needs** with a combination of soil and foliar applications, especially for mangoes.
*   **Use your granular micronutrient mix strategically**, understanding that foliar applications are likely more effective for immediate uptake in your soil conditions.
*   **Focus on increasing soil organic matter** to improve your CEC and overall soil health.
*   **Avoid gypsum** due to your already high calcium levels.

Run this by your local ag advisor to make sure it fits your specific situation and climate. They can provide tailored advice based on your exact soil test results and crop varieties.

BP:
Man I hate AI slop

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