WELO Soil Testing for 2024

Water scarcity is a growing concern worldwide, and as populations increase and climates change, the need for efficient water management practices becomes increasingly critical. In response to this challenge, many regions have implemented regulations and ordinances aimed at conserving water, particularly in landscaping practices. One such regulation is the Water Efficient Landscape Ordinance (WELO), which mandates water-efficient landscaping designs and practices. Central to WELO compliance is the thorough assessment of soil conditions through soil testing. In this article, we will delve into the significance of soil testing for WELO compliance, exploring its importance, methods, and implications for water-efficient landscaping.

Understanding the Water Efficient Landscape Ordinance (WELO):

The Water Efficient Landscape Ordinance (WELO) is a regulatory framework established to promote water conservation in landscaping projects. It applies to new construction, rehabilitated landscapes, and certain renovations, requiring compliance with specific water-efficient landscape design and installation standards. The goal of WELO is to reduce water consumption in outdoor landscapes, minimize irrigation runoff, and enhance overall water efficiency.

Importance of Soil Testing for WELO Compliance:

Soil testing plays a crucial role in WELO compliance as it provides essential information about soil composition, structure, and water retention capacity. By understanding soil characteristics, landscape professionals can design irrigation systems and select plant species that are well-suited to the site's conditions, thereby optimizing water use and minimizing water waste. The following are key aspects of soil testing for WELO compliance:

  1. Soil Composition Analysis: Soil testing involves analyzing the composition of the soil, including its texture, organic matter content, and nutrient levels. This information helps determine the soil's water retention capacity, drainage characteristics, and fertility, which are vital considerations for designing water-efficient landscapes.

  2. Water Infiltration Rate Assessment: One critical aspect of soil testing for WELO compliance is assessing the soil's water infiltration rate. This refers to the speed at which water penetrates the soil surface and percolates through the soil profile. Soils with high infiltration rates may require less frequent irrigation, while soils with low infiltration rates may necessitate modifications to irrigation systems to prevent runoff and water wastage.

  3. Determining Irrigation Requirements: Soil testing helps landscape professionals determine the irrigation requirements of a site based on soil moisture levels, plant water needs, and climate conditions. By accurately assessing soil moisture retention and distribution, irrigation schedules can be optimized to ensure water is applied efficiently and effectively, minimizing water loss through evaporation and runoff.

  4. Selection of Plant Species and Landscape Design: Soil testing results inform the selection of appropriate plant species and landscape design features that are compatible with the site's soil conditions. Plants that are well-adapted to the soil type and moisture levels require less water and maintenance, contributing to overall water efficiency in the landscape.

Methods of Soil Testing for WELO Compliance:

Several methods can be employed to conduct soil testing for WELO compliance, including:

  • Laboratory Soil Analysis: Soil samples are collected from the site and sent to a laboratory for comprehensive analysis, including tests for soil texture, pH, organic matter content, nutrient levels, and water retention capacity.

  • On-Site Soil Assessment: Soil texture and infiltration rate can be assessed directly on-site using simple techniques such as the feel and ribbon test for texture and the infiltration ring test for infiltration rate.

Implications for Water-Efficient Landscaping:

By integrating soil testing into the landscape design and installation process, stakeholders can ensure compliance with WELO requirements and promote water-efficient landscaping practices. The benefits of soil testing for WELO compliance include:

  • Reduced Water Consumption: Optimizing irrigation practices based on soil testing results can lead to significant water savings by minimizing overwatering and runoff.

  • Enhanced Plant Health and Landscape Resilience: Selecting plant species and designing landscapes that are well-suited to the site's soil conditions promotes healthier plant growth and resilience to drought and other environmental stresses.

  • Compliance with Regulatory Requirements: Soil testing ensures compliance with WELO standards, helping landscape projects meet regulatory requirements and avoid penalties.


Soil testing is a vital component of WELO compliance, enabling landscape professionals to design water-efficient landscapes that conserve water, enhance plant health, and comply with regulatory standards. By understanding soil composition, infiltration rates, and moisture retention capacity, stakeholders can optimize irrigation practices, select appropriate plant species, and design landscapes that promote water conservation and sustainability. Incorporating soil testing into landscape design and installation processes is essential for achieving water-efficient landscaping goals and mitigating the impact of water scarcity on the environment and communities.

Back to blog

Our tests

Have a question? Get in touch.

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.

Order a Soil Test Kit

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 info@alluvialsoillab.com

1 of 4