Plant Sap Analysis

What nutrients are in sap?

Since sap is predominantly sugar, analyzing the Brix of plant sap gives us an accurate representation of the sugars and other solubles available to the plant.

An appropriate pH level in plants is crucial to healthy growth. Most plants need to be slightly acidic, but not too much so. Analyzing the pH in sap gives a strong indicator of where the pH of the plant tissue will be in the upcoming days/weeks.

Measuring the EC of sap gives us a simple way to glimpse into the salt content of a given plant.

Aluminum is not needed by plants, but is often phytotoxic. Therefore levels are important to monitor to ensure Aluminum is not accumulating and going to harm your plants. A common cause of Aluminum toxicity is from improper management of Aluminum containing amendments such as Aluminum Sulfate.

Boron is less commonly analyzed, but still important for plant growth. Especially in crops such as strawberries, boron is a vital component to healthy root and fruit development. Analyzing the boron content of plant sap is most important both early in the season during root development, and late in the season during flowering and fruiting.

Maintaining proper calcium levels throughout the entirety of a season is critical to crop yield. Since calcium is immobile, symptoms of calcium deficiency show up first in newer growth. Taking a comparative sap analysis of your plant can help illustrate how calcium levels are changing. This allows you to find gaps in fertilizer applications, regulate balancing with other nutrients, or identify slow root growth preventing the plant from uptaking enough.

Monitoring the ratio between calcium and potassium is also vital. It ensures plants are utilizing their calcium concentrations properly, so we include a K/Ca statistic along with our tests to highlight if your plants are maintaining a healthy balance.

Chlorine is a necessary nutrient to plants in small quantities to facilitate photosynthesis. However, toxic levels are common, especially in hydroponics. Keeping an eye on your chlorine levels ensures your crop isn’t suffering chlorine toxicity due to other nutrient applications.

Plants require small copper levels to ensure healthy protein and enzyme production. Copper uptake can be hindered by zinc concentrations, and excessive copper in acidic soil can cause toxicity in plants. Analyzing your plants’ copper levels in the sap gives the best look at what sap your plant has available. Copper is also not very mobile in plants, so Comparison Sap analysis allows you to see how copper availability has changed during the season.

Iron is an important metal for all plants, and deficiencies will cause chlorosis, necrosis, and bleaching of newer leaves. Plants require acidic soil for proper iron uptake, and low iron levels can indicate pH problems (which can cause many other issues). Monitoring the iron levels in crop sap is a highly accurate way to ensure your plants are uptaking it into their roots.

Magnesium deficiencies can also cause chlorosis. As magnesium is a highly mobile nutrient though unlike some of the others, these symptoms appear on older growth leaves first. Both individual and comparison sap tests can help growers ensure their plants have healthy levels of magnesium.

Manganese is another important nutrient when managing Iron, Calcium, and Magnesium levels. Excess Manganese can affect a plants uptake of iron, calcium, and magnesium, and deficiencies can cause chlorosis symptoms similar to magnesium or iron.

Molybdenum is critical to a plant’s ability to break down Nitrate into usable Nitrogen. Improper Molybdenum levels can hamper your crops ability to soak in Nitrogen during application, and waste valuable application product. Lower nitrogen levels also mean a large impact to crop health and yields. Molybdenum deficiency can occur even in acidic soil that plants love, and can cause crop leaves to pale and roll at the margins.

Nickel is only needed by plants in small doses, and is readily available in almost all soil. However, Nickel deficiencies can occur, especially in hydroponic settings. Analytical testing, especially sap testing, is the only way to really know if your plants are deficient in nickel.

Nitrogen is one of the most important nutrients to plants, and is one of the most difficult to get an accurate reading on. Plants absorb Nitrogen as Nitrate and Ammonia, both of which are highly mobile inside the plant and out. Nitrogen in sap gives the most real-time view of what your plants have available to use in the next few days. This quickly available info allows you to address nitrogen problems BEFORE they happen.

For optimal nitrogen management, comparison sap tests are recommended. This allows you to get the best idea of how your plants’ nitrogen availability is changing. We also recommend sampling your crops on regular intervals. Doing so will ensure there are no gaps in nitrogen availability to hinder your crops’ yield.

Phosphorus is another highly mobile nutrient in plants, and is needed for healthy plant tissue growth. Deficiencies of phosphorus can be noticed in older leaves first. Signs include stunted growth, and a red color due to elevated anthocyanin pigments. Excess phosphorus can prevent plants from absorbing zinc, iron, and copper into the roots, leading to deficiencies in those micro-nutrients. Testing a comparison between old growth sap and new growth sap can show trends in phosphorus movement.

Potassium is a crucial nutrient to plant yields and crop health, and is absorbed in abundance by plants. Similar to chlorine, magnesium, nitrogen, and phosphorus – potassium is highly mobile inside plants. It is used in new tissue development all over the plant, and is an essential macro-nutrient. Low potassium levels can cause flecking or mottling on leaves, and may cause wilting to your crops. Extended periods without ample potassium will cause plants to begin to die around the edges of leaves, and fruits to be underdeveloped and stay underripe.

Monitoring the ratio between potassium and calcium is also vital to ensure that plants are utilizing their potassium concentrations properly, so we include a K/Ca statistic along with our tests to highlight if your plants are maintaining a healthy balance between the two.

Selenium is not well understood to be essential for plant growth. However, small amounts of Selenium are known to improve a plants livability and survival in cold and drought weathers. Selenium also can help plants endure toxicity from metals from improper fertilizer supplement applications. In addition, consumption of plant selenium is the main source of selenium for humans. Monitoring crop content of selenium can be beneficial for nutritional information.

Silicon is beneficial to plant growth, but is particularly necessarily in grain crops such as rice. It is needed for healthy shoot development, and protection from abiotic stressors such as drought and frost. Silicon can also help facilitate plants to uptake other essential nutrients such as potassium. Keeping an eye on silicon levels with sap testing allows you to better understand plant health concerns, and keep nutrient levels where they need to be.

While not really an essential nutrient for plants, sodium serves a functional purpose in plants by providing similar growth support as potassium. Sodium can substitute in when potassium levels are deficient. However, more commonly are toxic sodium levels due to excess sodium in irrigation and hydroponic water. Monitoring your sodium levels in your plants’ sap can indicate whether there is an environmental factor that could be putting your crops, and yield, at risk.

Sulfur is an important nutrient for crops. Deficiencies in sulfur are uncommon, but are very dangerous. More common are sulfur excesses due to it being a common secondary ingredient in fertilizers. Plants are quite resilient to high sulfur content, but sulfur in abundance can prevent proper nitrogen uptake, and decrease soil pH below a safe acidity. For that reason, keeping an eye on sulfur content in sap is particularly important for hydroponic growers. Applying sulfur-based fertigation solvents can quickly pose a risk of excessively acidic conditions.

Similarly to other metals, plants need zinc in small, available quantities. Incorrect zinc levels can cause problems such as shortened internodes, interveinal chlorosis, and toxicity causing stunted root growth and small leaves. The zinc levels analyzed in plant sap is the best indicator of how much zinc the plant is currently receiving as it is not highly mobile and can be indicative of pH and copper problems.

New from NEWAGE!

Now available at NEWAGE Laboratories is Plant Sap Analysis! Plant sap testing provides more dynamic crop information than soil test or tissue testing alone, and it helps maximize your yields. Sap analysis is particularly beneficial to production and yields when analyzed routinely, allowing farmers to make adjustments to amendments and additives.

During varying growth stages, crop nutrient demands can shift drastically. Analyzing the sap of your plants will help facilitate accurate adjustments in crop nutrient amendments to correct imbalances and deficiencies. The adjustments help you maintain target yield goals and optimize amendment input costs.

What is Plant Sap Analysis?

When analyzing the sap of a plant, whether it be blueberries, peanuts, rice, hemp, soybeans, or any other crop, we take a closer look at the spectrum of nutrients that are active in the plant. 

*Listed to the left are the relevant nutrients we look for in sap, and listed below is a chart to help identify nutrient deficiencies due to competing uptake of elements.

Listed above is an interpretation of competing nutrients in sap uptake. Deficiencies of nutrients in the upper-quadrants appear in the upper-parts of plants on the new growth. Deficiencies of nutrients in the lower-quadrants appear in the lower-parts of the plants on the old growth. Nutrients in diagonal quadrants generally compete with each other.

Individual Sap

Individual sap tests allow you to get a full rundown of the nutrients actively flowing through your plants’ xylem and phloem at the time of testing. This is a more accurate representation of what your plant has available compared to soil and tissue tests.

Translocative Sap

Translocative sap analysis combines the power of individual sap testing with the trusted knowledge that comes with soil testing. We compare what nutrients are available in the soil with what your plants are actively taking up through the roots. Translocative sap tests are most informative when taken periodically over a season. This allows you to monitor what your crops are really absorbing from their soil amendments, and lets you make helpful and informed management decisions during the growing season when it is most important.

Comparison Sap

Instead of treating a plant as having uniformity in its nutrient content, we take a comparative look between the older and newer growth of the plant. Combining analyses of sap between leaves of different growth stages gives additional insight into how the availability of nutrients has shifted over the season. This can be particularly informative for hydroponic, aeroponic, and other soil-less growers who want to see how their plants nutrition uptake changes over time.

November 9th, 2023:      Specialty Crops Annuals     (Potatoes, Watermelon, Strawberries etc.)

December 7th, 2023:         Specialty Crops             (Trees, Vines, and Berries) 

January 18th, 2024:             Cannabis Spp.

February 8th, 2024:             Cereal/Oil Crops                  (Wheat, Soybean, Canola etc.)       

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NEWAGE Laboratories teamed up with Charlie McKenzie from CropTalk to help break down why sap analysis is such a powerful analytical tool for growers across the globe. 


One-Time Buy

Small Pre-Purchased Bundles
– $78.75
(with 25 pairs) 

Large Pre-Purchased Bundles
– $70
(with 50+ pairs; free consultation time included) 

Prices include TWO tests! Choose from:

Translocative Sap Analysis

  • Sap Analysis (New Leaf)
  • Rapid Soil Tests

Comparative Sap Analysis

  • Sap Analysis (New Leaf)
  • Sap Analysis (Old Leaf)

Fruit Sap Analysis

  • Sap Analysis (Fruit)
  • Rapid Soil Tests