Healthy Soils Strawberry Meeting Recap

Thank you to everyone who attended our strawberry meeting on January 13th! It was great to see everyone and I hope you found the content valuable. Here is a quick recap of the presentations:

Eryn Wingate: Soil Health

  • Healthy soils are living ecosystems
  • Microbes are ecosystem engineers
  • Plants and microbes evolved together over hundreds of millions of years
  • Cation exchange on clay and organic matter surfaces hold nutrients in the soil and release nutrients into soil solution

Watch the video!

Video Notes:

A couple of times I misspoke and said cations have negative charge. Corrections:

Cation = positively charged atom in a water solution

Clay surfaces have negatively charged exchange sites that attract and hold cations.

Other Presentations Given on January 13th:

Daniel Cathey, Yara: Balancing Nutrients in Strawberry Production

  • Provide plant nutrients in the appropriate form in the right ratios, and at the right time.
  • By applying nutrients at the optimum rate and timing we can get better tasting fruit, longer shelf life, and higher disease resistance.
  • It is a challenge to balance fertilizer requirements with salinity management. We must provide enough fertilizer without raising soil solution EC above crop tolerance levels.
    • In general, strawberries are very sensitive to salinity, but some varieties are more sensitive than others.

Paul Crout: Managing Soil Salinity in Berries

  • Salts impact crop production through two mechanisms:
    • Salts increase water stress- high EC makes its harder for plants to get enough water, even when the soil is very moist.
    • High salt content in the soil cause nutrient toxicity, especially sodium and chloride toxicity. Sodium and chloride are absorbed through roots and leaf surfaces, and accumulate in leaf tips.
  • Take soil samples from the root zone, not the edges of the bed. EC in the wetting zone will be lower than EC far away from the drip emitter. Salts follow the wetting front and accumulate where they are deposited at the driest spots in the bed.
  • Sodium competes with potassium for plant uptake, so if there is too much sodium in the root zone, the plants might be potassium deficient.
  • To get rid of excess sodium, apply calcium and leach the sodium with excess water. Calcium will replace sodium on cation exchange sites and the sodium will leach down the soil profile past the root zone when enough irrigation water is applied. Soil amendments include:
    • Calcium thiosulfate
    • Gypsum
    • Elemental sulfur
    • Sulfuric acid injection
  • Use the LR equation to determine how much irrigation water you need to lower soil solution EC to the desired level. See this pdf for the equation and explanation: Managing Salts by Leaching

Paul Crout, Helena: Humic Acids: Where They Come From and Their Utility in Agriculture

The dark surface layer in this soil is rich in humus.
  • Humic acids in many fertilizer products are derived from a substance called leonardite mined from rock in New Mexico. Leonardite formed from ancient organic matter deposits.
  • Humus is fully decomposed soil organic matter. It is dark brown or black and contains no recognizable plant tissue. Humus can be divided into two major fractions:
    1. Insoluble Humin (solid)
    2. Soluble Humic Acids (liquid)
  • Humic Acids are categorized into two more fractions
    1. Humic Acids (soluble only in high pH solutions)
    2. Fulvic Acids (soluble in high and low pH solutions)
  • Humic and fulvic acids are umbrella terms that refer to many different types of organic acid molecules. An “organic molecule” is a carbon-based molecule.
  • Humic acids coat mineral surfaces and act like glue facilitating soil aggregation and soil structure development.
  • Humic acids act as nutrient sponges. They attract and hold both positively and negatively charged nutrients.
  • Fulvic acids act as nutrient transporters. They increase plant nutrient uptake.
  • Functional groups on organic acid molecules are responsible for properties such as nutrient complexing, cation exchange capacity, and anion exchange capacity, and plant genetic expression.
  • Plants grown in soil with lots of humic substances are less prone to stress, grow with more vigor, and produce higher yields with better quality.

Mike Ravalin, Helena: Irrigation Management

  • Always test your irrigation water to determine concentrations of bicarbonates, sodium, chlorides, etc.
  • Drip system uniformity determines fertilizer uniformity. The fertilizer goes where the water goes.
  • Use humic acid fertilizer amendments to complex plant nutrients, and investigate differences between products before buying.

Jim Dana, AgriWest

  • Create nutrient management plans in advance and adjust fertilizer amendments in season based on plant tissue, soil, or lysimeter lab results.
  • Apply nutrients based on the 4Rs of nutrient management
    • Right Rate
    • Right Source
    • Right Time
    • Right Place
  • Keep track of fertilizer inputs and yields to analyze the effectiveness of your fertilizer program at the end of the season.

Patricia Dingus, Yara: How to Use Yara CheckIt! Mobile App

  • CheckIt! Can be downloaded onto iphones, ipads, android phones, and tablets
  • The app provides photos of crop nutrient deficiencies and toxicities.
  • Users can search for photos based on symptoms such as leaf tissue chlorosis
  • Users can also view photos organized by nutrients
  • Get the app at:

We had an info packed meeting! Call or email me, Eryn, anytime for fertilizer recommendations or nutrient management advice. I also provide nutrient application tracking services to help you monitor pounds N, P, K etc. applied throughout the season.

Phone: (805)437-9648           Email: