Soil Testing in Fresno, California

Fresno, located in California's Central Valley, is characterized by its agricultural prominence and unique soil diversity. The city's soil types are influenced by the region's climate, topography, and historical factors, making Fresno a vital hub for agricultural productivity. From the fertile farmlands to the urban landscapes, Fresno's soils play a critical role in shaping the city's economy, environment, and land use practices. Let's explore the different soil types found in Fresno and their significance.

  1. Alluvial Soils: Fresno's soil composition is strongly influenced by its proximity to the San Joaquin River and its tributaries. Alluvial soils, which have developed from sediment deposition by rivers, dominate the landscape in the Central Valley. These soils are characterized by their fertility and high nutrient content, making them ideal for agriculture.

    The fertile alluvial soils of Fresno have supported the region's thriving agricultural industry for decades, cultivating crops like almonds, grapes, and various fruits and vegetables. These soils are a key contributor to Fresno's reputation as one of the world's most productive agricultural regions.

  2. Sandy Loam Soils: Sandy loam soils are common in the Fresno area and are particularly well-suited for agriculture. Sandy loam is a balanced soil texture that offers good water-holding capacity, drainage, and nutrient retention. This type of soil is conducive to root growth and allows for efficient nutrient uptake by plants.

    Many of Fresno's major crops, including grapes, citrus fruits, and nuts, thrive in sandy loam soils, contributing to the city's agricultural diversity and economic prosperity.

  3. Clay Soils: Clay soils are present in certain regions of Fresno and the surrounding areas. These soils have fine particles that retain water and nutrients effectively, but they can become compacted and poorly drained, particularly during heavy rainfall.

    Proper soil management practices, such as soil amendment and aeration, are essential for preventing compaction and ensuring proper drainage in clay-rich areas. Some crops that are more tolerant of waterlogged conditions can thrive in these soils.

  4. Volcanic Soils: In some parts of Fresno, particularly in the foothills of the Sierra Nevada Mountains, volcanic soils can be found. These soils are rich in minerals and nutrients due to their formation from volcanic ash and rock. Volcanic soils support healthy plant growth and are often used for agriculture.

    The presence of volcanic soils contributes to the diversity of crops grown in the region and showcases the geological history of the area.

  5. Urban Soils: As an urban center, Fresno features a mix of anthropogenic soils resulting from construction, development, and landscaping activities. Urban soils can vary widely in composition and quality, depending on the materials used and the history of the site.

    Effective soil management practices are important for promoting healthy vegetation in urban environments. Proper soil testing, appropriate plant selection, and irrigation techniques ensure that urban green spaces and landscaping thrive.

  6. Alkali Soils: Some regions of Fresno experience the presence of alkali soils, which have high levels of soluble salts. These soils often have white, crusty salt deposits on the surface. Alkali soils can pose challenges for agriculture, as excessive salt levels can hinder plant growth.

    Managing alkali soils involves leaching excess salts from the soil through proper irrigation practices. Some crops and plants are more tolerant of saline conditions and can be cultivated in areas with alkali soils.

  7. Loess Soils: Loess soils, which are formed from wind-blown deposits of fine particles, are present in certain parts of Fresno. These soils are typically well-drained and fertile, supporting a variety of crops and vegetation.

    Loess soils contribute to the agricultural productivity of Fresno and showcase the complex processes that shape soil formation over time.

For soil testing supplies, we recommend reaching out to these garden centers:

  • Lotus Gardens Outdoor Living Center Inc at 2271 N Grantland Ave, Fresno, CA 93723, USA. It has a 4.7 star rating on Google Maps.
  • Belmont Nursery at 7730 E Belmont Ave, Fresno, CA 93737, USA. Spacious nursery offering flowers, trees & shrubs, plus consultation services & plant rentals. It has a 4.5 star rating on Google Maps.
  • Green Hills Nursery at 2408 N Armstrong Ave, Fresno, CA 93727, USA. It has a 4.8 star rating on Google Maps.
  • Garden Center at The Home Depot at Home Depot, 7150 N Abby St Garden Center, Fresno, CA 93720, USA. It has a 4.3 star rating on Google Maps.
  • Gazebo Gardens Inc at 3204 N Van Ness Blvd, Fresno, CA 93704, USA. It has a 4.7 star rating on Google Maps.
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Understanding Soil Health

Assessing soil health involves looking at physical, chemical, and biological components.

Soil health is a fundamental concept that underpins the success of agriculture, gardening, and land management practices. It refers to the overall well-being and vitality of the soil ecosystem, encompassing physical, chemical, and biological aspects. Understanding soil health is crucial for maintaining sustainable and productive landscapes while also contributing to environmental conservation.

  1. Physical
    The physical properties of soil play a critical role in its health. These properties include soil texture, structure, compaction, and water-holding capacity. Soil texture refers to the proportions of sand, silt, and clay particles in the soil. A balanced texture allows for adequate water drainage and retention, preventing waterlogging and drought stress. Soil structure influences root penetration, aeration, and nutrient movement. Healthy soil structure promotes a friable and well-drained medium for plant growth.
  2. Chemical
    Soil chemistry directly affects nutrient availability and plant growth. Key chemical factors include soil pH, nutrient content, and the presence of contaminants. Soil pH measures the soil's acidity or alkalinity and profoundly influences nutrient uptake by plants. Nutrient content, including macronutrients like nitrogen, phosphorus, and potassium, must be in balance to support healthy plant growth. Monitoring and maintaining proper nutrient levels through fertilization are essential for maximizing crop yields and preventing nutrient deficiencies.
  3. Biological
    The biological component of soil health pertains to the diverse array of microorganisms, insects, and other organisms that inhabit the soil ecosystem. These organisms play crucial roles in nutrient cycling, organic matter decomposition, and disease suppression. Soil microorganisms break down organic matter, releasing nutrients that are subsequently made available to plants. A rich and diverse soil microbiome contributes to enhanced nutrient availability and plant resilience against diseases.

Our Soil Tests

We provide a range of soil tests from basic chemistry, to texture/infiltration rate, all the way to biology.

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Basic Soil Health Test

The Basic Soil Health Test is an excellent starting point for understanding your soil's condition. It offers a comprehensive analysis encompassing pH levels, nutrient content, CEC (Cation Exchange Capacity), salts, and organic matter. This budget-friendly test is ideal for identifying potential soil health issues and establishing a solid foundation for further management.

Full Chemistry Test

Our Full Chemistry Test provides a detailed assessment of your soil's quality, guiding you towards healthy and sustainable soil management practices. Through an extensive analysis, we examine macro and micronutrient levels, pH, CEC, organic matter, and salinity. This comprehensive understanding empowers us to create tailored recommendations for soil amendments and treatments, optimized for the specific plants you intend to cultivate. By optimizing your soil's chemistry, you can expect to foster more robust and vibrant plant growth.

Complete Soil Health Test

Uncover a deeper understanding of your soil's health with the Complete Soil Health Test. This comprehensive analysis goes beyond the basics, measuring nutritional factors and examining soil texture. It covers macro and micronutrients, organic matter, pH, CEC, as well as sand, silt, and clay percentages. Additionally, we assess carbon sequestration levels, providing you with a holistic view of your soil's composition. The personalized recommendations derived from this test empower you to make precise adjustments to enhance your soil's health and productivity.

MWELO Soil Management Report

For those navigating California's MWELO guidelines, our MWELO Soil Management Report is an indispensable resource. This report not only ensures compliance but also promotes sustainable and thriving landscapes. It includes comprehensive data such as soil texture, infiltration rate, pH, total soluble salts, sodium content, and organic matter percentage. With amendment recommendations, optionally tailored to specific plant types, and annual maintenance tips, you'll be equipped to create landscapes that are both aesthetically pleasing and environmentally responsible.

Heavy Metals

The Heavy Metals analysis is a vital tool in assessing potential soil contamination. Given the uncertain history of properties, this analysis identifies the presence of heavy metals that might have accumulated due to past activities or nearby industrial sources. With results available in approximately nine business days, you'll gain insights to ensure the safety and health of your soil.

Soil Food Web

Explore the intricate world beneath the surface with our Soil Food Web analysis. By estimating population sizes of essential trophic groups—bacteria, fungi, protozoa, and nematodes—we unveil the microbiological health of your soil. Additionally, we identify specific organisms within these groups, providing insights into the soil's successional level and overall condition. This analysis is applicable to soil, compost, and compost tea samples, offering a holistic perspective on your soil's biological vitality.

Pesticide Screening

The Pesticide Screening can detect hundreds on common pesticides that may have been applied or drifted from nearby sources.

Herbicide Screening

The Herbicide Screening plays an important role in ensuring the safety of your soil and plants. By detecting the presence of herbicide residues, this test can indicated whether a soil has had history of herbicide applications.

See our other tests.

Regenerative Soil Management Practices

Working with nature to improve soil means implementing practices like cover cropping, mulching, and composting.

Cover Cropping

Cover cropping involves planting specific crops during non-growing seasons to cover and protect the soil. These crops enhance soil structure, prevent erosion, suppress weeds, and provide organic matter when incorporated into the soil. Leguminous cover crops also contribute nitrogen fixation, enriching soil fertility naturally. Cover cropping is a sustainable method that improves soil health and biodiversity.


Mulching entails covering the soil surface with organic materials like straw, leaves, or wood chips. Mulch conserves soil moisture, moderates temperature fluctuations, suppresses weeds, and prevents soil erosion. As the mulch breaks down, it contributes organic matter, enriching the soil's structure and fertility. Mulching is an effective and easy way to maintain soil health.


Composting transforms organic waste into nutrient-rich compost. Incorporating compost into the soil enhances its structure, moisture retention, and fertility. Compost also introduces beneficial microorganisms that aid in nutrient cycling and disease suppression. Composting not only reduces waste but also revitalizes soil, making it an essential component of sustainable gardening.

Water Conservation Techniques

Implementing water-efficient practices such as drip irrigation, rainwater harvesting, and utilizing drought-resistant plants minimizes water use and reduces soil erosion. Conserving water in landscapes maintains soil moisture, supports plant growth, and sustains overall soil health. Water conservation techniques are vital for responsible gardening in arid and water-scarce regions.

If you have any questions feel free to get in touch with the Alluvial Soil Lab team at (831) 216-1367 or at

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