Multi-Depth Soil Moisture Data

Summed Moisture Graph

Summary: A summed moisture graph aggregates soil moisture across all depths, providing a quick snapshot of total root-zone moisture.

Value: Shows the total water content in the soil profile, helping growers assess whether the entire root zone has adequate moisture. This is especially useful for determining irrigation needs and preventing overwatering or underwatering.

Summed Moisture Graph Units

For summed moisture graphs calculated from volumetric water content (VWC) measurements using multi-depth soil moisture probes, the units should typically be expressed as millimeters of water (mm) per depth or layer. You can easily use any volume metric that is expressed as a length (mm, in, m, acft, etc.) Here’s how it works:

1. Volumetric Water Content (VWC):
   This is measured as a fraction (e.g., 0.2 or 20%) or percentage of the soil volume, representing the volume of water per unit volume of soil.

2. Converting VWC to Depth of Water (mm):
   Multiply the VWC (as a fraction) by the thickness of the soil layer (in millimeters) being measured at that depth.
   Example: If the VWC is 0.2 (20%) in a 10 cm (100 mm) layer, the depth of water is: 0.2×100=20 mm of water.0.2 times 100 = 20 , \text{mm of water.}0.2×100=20mm of water.

3. Summing Across Depths:
   For multi-depth probes, calculate the water depth for each layer and sum them to get the total water content across the profile.
   Example: For three layers of 100 mm depth with VWC values of 0.2, 0.15, and 0.1: Total moisture=(0.2×100)+(0.15×100)+(0.1×100)=20+15+10=45 mm.\text{Total moisture} = (0.2 times 100) + (0.15 times 100) + (0.1 times 100) = 20 + 15 + 10 = 45 , \text{mm.}Total moisture=(0.2×100)+(0.15×100)+(0.1×100)=20+15+10=45mm.

Final Units

The summed moisture graph should use millimeters (mm) as the unit, representing the total depth of water in the soil profile. This unit provides an intuitive sense of how much water is stored in the soil, comparable to rainfall or irrigation amounts.

Graph with All Probe Depths on the Same Graph but Split by Data Type

Summary: This graph overlays data of the same type (e.g., moisture) across all probe depths, making it easy to spot depth-based trends.

Value: Allows growers to compare trends across different soil depths for one specific variable (e.g., moisture, temperature, or salinity). This helps identify patterns such as uneven water distribution or salt buildup at certain depths.

Series of Graphs Split by Probe Depth

Summary: Separate graphs for each depth show soil moisture, temperature, and salinity, offering detailed insights into conditions at individual depths.

Value: Provides a detailed view of conditions at each depth, helping growers understand how irrigation or environmental changes affect different soil layers. It’s particularly useful for managing root-zone conditions for deep- and shallow-rooted crops.

Graph Displaying Soil Moisture, Temperature, and Salinity Across All Depths

Summary: A single graph displaying all data types across all depths provides a comprehensive overview of soil conditions.

Value: Enables holistic monitoring of all variables at all depths simultaneously, giving a complete picture of soil health. Growers can identify interactions, such as how salinity changes with moisture or temperature, across the entire profile.

Field Capacity Threshold

Represents the maximum amount of moisture the soil can hold after excess water has drained. It serves as a guide to indicate when no further irrigation is necessary to avoid overwatering.

Onset of Stress Threshold

Indicates the soil moisture level below which plants begin to experience water stress, signaling the need for irrigation to maintain crop health and yield.