Factors Affecting In-field Soil Moisture Variability and Its Effect on Irrigation

Project Overview

GS19-214
Project Type: Graduate Student
Funds awarded in 2019: $10,845.00
Projected End Date: 02/28/2021
Grant Recipient: Mississippi State University
Region: Southern
State: Mississippi
Graduate Student:
Blade Hodges
Email
Major Professor:
Dr. Mary Love Tagert
Email
Mississippi State University

Information Products

Commodities

  • Agronomic: corn, soybeans

Practices

  • Crop Production: irrigation, water management

    Proposal abstract:

    There have been numerous studies on soil moisture as it pertains to irrigation in Mississippi, but more work is needed in the agricultural region known as the Blackland Prairie, located in east central Mississippi. Here, an increasing number of producers are implementing irrigation. Because it is not economical to access groundwater due to the depth of the aquifer, most producers here use surface water for irrigation. Producers have a finite amount of water to use for irrigation through the growing season, so it is critical that they conserve water and irrigate efficiently. Sprinkler irrigation is the primary application method, to accommodate the changing topography across the landscape. Soil moisture sensors conserve water while maintaining yields on irrigated fields, by better timing irrigation applications to match actual crop water needs. The goal of this project is to evaluate the correlation of plant vegetation characteristics (plant height, leaf area index) and other variables (soil texture, topography) to soil moisture in the active rooting zone, to determine if there is a good surrogate for soil moisture measurements. The Decision Support System for Agrotechnology Transfer crop model will also be used to evaluate the effects of climate on vegetative characteristics and soil moisture. The results from this project will help farmers determine the ideal number of sensor sets needed over a given area and the best placement of sensors within a field. Ultimately, producers will conserve more water by improving their use of soil moisture sensors to make better irrigation management decisions.

    Project objectives from proposal:

    • Measure in-field spatial and temporal variability of soil moisture in the active rooting zone of a soybean-corn rotation using Watermark GMS sensors.
    • Evaluate the correlation of root zone soil moisture to soil texture and crop variables.
    • Determine if the variability of in-field soil moisture is great enough to indicate a different irrigation schedule for different areas of the field.
    • Share project results with producers and stakeholder groups.
    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.