Water Resources Research Act Program

Details for Project ID 2015NE266B

Design of Multi-Scale Soil Moisture Monitoring Networks in Agricultural Systems Using Hydrogeophysics

Institute: Nebraska
Year Established: 2015 Start Date: 2015-03-01 End Date: 2016-02-28
Total Federal Funds: $20,000 Total Non-Federal Funds: $40,001

Principal Investigators: Trenton Franz

Abstract: The Food and Agriculture Organization of the United Nations (FAO) estimates an increase of 70 percent in cereal grains production will be necessary to feed the projected nine billion people worldwide by 2050, placing great demand on dwindling agricultural water resources. Currently, 70 percent of global anthropogenic consumptive water use is for agriculture where irrigation agriculture accounts for 40 percent of global food production. However, global trends in consumptive water use indicate a growing yet unsustainable reliance on groundwater resources. Despite its critical importance in global food security, water paradoxically is wasted at an alarming rate. On the global scale, Clay (2004) estimates 60 percent of the 2,500 km3 used for agriculture each year is “wasted” through inadequate water conservation, losses in distribution, and inappropriate times and rates of irrigation. Given the massive time, labor, and economic costs of water application, a primary challenge is to better understand how much water in the soil is available for use by plants. The underlying difficulty when measuring soil moisture availability is its inherent heterogeneity in time and space in both natural and agricultural settings, consequently requiring intensive time and labor sampling strategies in order to accurately quantify large areas. Thus, there is a critical need to quantify soil moisture storage at the application scales where water management decisions are made with accurate and pragmatic techniques. In the absence of such techniques, the development of efficient water application strategies and agricultural production sustainability will likely remain difficult. My long-term goal is to develop effective strategies to improve the efficiency of water use in irrigated agriculture. The goal of the work proposed in this application is to develop improved hydrogeophysical procedures for accurately quantifying soil moisture storage at scales where water management decisions are made. My central hypothesis is that application of hydrogeophysical techniques will allow accurate and pragmatic measurement techniques of soil moisture storage at critical management scales. My hypothesis has been formulated, in large part, based on existing literature and my own preliminary findings that demonstrate that hydrogeophysical procedures can accurately quantify soil moisture storage at a variety of spatiotemporal scales. The goal of this application will be achieved through two objectives: Objective 1: Identify hydrogeophysical techniques to quantify soil moisture storage of individual management sections within agricultural fields. My working hypothesis is that combining spatial datasets from mobile cosmic-ray neutron probes with in-situ point sensors will allow me to develop statistical relationships for predicting realtime soil moisture storage estimates of individual management zones distributed across the entire field. The development and delivery of realtime data is essential for use in decision support tools. Objective 2: Identify hydrogeophysical techniques to quantify soil moisture storage of many agricultural fields. My working hypothesis is that combining stationary and mobile cosmic-ray neutron probes will allow me to develop statistical relationships for predicting realtime soil moisture storage estimates of individual fields distributed across the entire watershed.