Recipient Organization
UTAH STATE UNIVERSITY
(N/A)
LOGAN,UT 84322
Performing Department
Plants, Soils & Climate
Non Technical Summary
Soil is one of the most crucial components in supporting life, food security, and ecosystem services on Earth. As a key part of the critical zone (Earth's surface involving rock, soil, water, air, and living organisms) that determines agricultural and environmental sustainability; soils transform and supply water, energy, nutrients, and organic materials and moderate the supply of water and nutrients to plants. Soil is where biological and chemical transformations occur, and it is the domain that sustains all flora and fauna ecosystem cycles. Meanwhile, changing societal food and energy demands, land use and climatic conditions are imposing ever greater stresses on soil. Recognizing the importance of soils for food security, agriculture, and in mitigation of climate change and sustainable development, the United Nations declared the International Year of Soils, 2015 (IYS 2015) to raise awareness worldwide. The protection and stewardship of this crucial resource can be only assured through a better understanding of soil processes at different space and time scales, thus soil physics plays an important role in understanding the physical processes at work. This Utah State University proposal is part of the W4188 project that seeks to address national needs research. The proposal also highlights overall efforts to improve environmental monitoring, implement basic soil physics research, and reach out to a broader scientific community (e.g., plant science, ecology, chemistry, and microbiology), and educate and communicate to stakeholders and colleagues within and outside our traditional disciplines. Specific research will target development of plant growth media for reduced gravity conditions on the ISS, moon and Mars. Development of a commercial Thermo-Time Domain Reflectometry sensor yielding unprecedented soil bulk density and porosity determination. In collaboration with the Utah Climate Center, we will develop soil moisture mapping capability using the vast state-wide network of soil moisture sensors from state and federal agencies. The resulting knowledge, benefits and products will benefit NASA science goals to produce plants in reduced gravity environments for both food and mental well-being of astronauts. The commercialization of more than a decade of research will benefit agricultural and environmental applications to better track soil density and porosity evolution over time resulting from tillage and subsequent trafficking activities, irrigation and plant growth and harvest. We expect the state-wide soil moisture map to improve estimates of flood, drought, fire and other natural occurring events impacted by soil moisture as a major benefit from this resource development.
Animal Health Component
30%
Research Effort Categories
Basic
40%
Applied
30%
Developmental
30%
Goals / Objectives
1. Connect new understandings of storage and transport of mass and energy to assess environmental change. See attachment.
2. Develop and test new instrumentation, methods and models to improve the mechanistic understanding of soil processes and the quality of soil information and knowledge. See attachment.
3. Integrate scale-appropriate methods to improve decisions related to the management of soil and water resources.
Project Methods
Objective 1. Connect new understandings of storage and transport of mass and energy to assess environmental change.Characterization and description of porous medium physical properties is critical for understanding the vadose zone and this becomes even more critical in containerized root systems such as in greenhouse and potted plant industries. Since the 80's scientists have been working to design and develop plant growth media suitable for space applications and reduced gravity fields, such as found on orbit, Earth's Moon or Mars. We (UT, ID, NV) intend to expand our previous work on porous medium design that optimizes water, nutrients and oxygen supply to plant roots in containerized systems that experience reduced gravity force. A variety of porous media options will be considered, including aggregates, floral foam, fabric and 3D printed geometries. Key aspects of the design will be the deliberate segregation of water- and air-filled pores using pore-size contrast and at ratios leading to optimal delivery of water and gas exchange supporting microbial and root respiration. An iterative process of design, build and characterize is anticipated to lead to one or more optimal rooting media that satisfy objectives described by the physical control system intended for space flight. Additional testing will include the growth of target crops for space and assessment of their productivity using a water and nutrient injection system, compared with a traditional potting medium. One key difference between porous media on earth and in orbit is the distribution of water, which tends to be uniform in space in a homogeneously pore-sized medium but the distribution is skewed by gravity on earth. Thus attempts will be made to design the porous medium pore size distribution which counteracts the gravity-induced water content gradient, leading to more uniform water content distribution.Once characterized, the various porous medium physical properties will be input to numerical modeling code to run simulations of the earth-based system for comparison and calibration, followed by adjustment of the gravity term, leading to opportunities to simulate behavior of the system under reduced gravity. These simulations will initially be 1-dimensional with the possibility of a 3-dimensional simulation for advanced study. Measurement and modeling of nutrient content over the growing cycle will facilitate understanding of the required nutrient injection rates and management protocols. Measurements of oxygen within the porous medium will also be carried out to understand the diffusion rates and respiration demand of the system, aiming to optimize the ratio of water- and air-filled pores. Eventually we aim to test the resulting porous medium on orbit on the ISS and potentially on the moon or Mars.Objective 2. Develop and test new instrumentation, methods and models to improve the mechanistic understanding of soil processes and the quality of soil information and knowledge.2.1. Improved multifunction measurement devicesUtah State University has been developing a heat pulse sensor for over 10 years, leading to measurement capabilities for determination of thermal properties and to a number of secondary determinations including soil water flux, soil heat flux, subsurface evaporation, and thermo-dielectric measurements using a 100 MHz electromagnetic sensor coupled with the heat pulse sensor (Sheng et al., 2016). In 2018 USU and Acclima Inc. received a USDA-SBIR grant to develop a Thermo-Time Domain Reflectometry (T-TDR) sensor. The T-TDR provides measurements of soil volumetric water content and heat capacity, from which the soil bulk density and soil porosity can be determined. This instrument has been employed in research since 1996 (Noborio et al., 1996) but has yet to be commercialized.The Acclima True TDR-310H employs faster rise time than traditional TDR devices, allowing shorter rods of just 5 cm length. Both TDR and heat pulse technologies have been well-developed independently, our aim is to combine these into a single sensor. Once we have a working prototype, there will be a number of testing phases to determine the quality of the sensor's measurement capabilities for the various outputs, including temperature, electrical conductivity, permittivity, thermal conductivity, thermal diffusivity, heat capacity, and water content. This testing will include a variety of liquids and granular porous media including soil. There will also be a series of updates and improvements to the sensor that will necessitate additional testing and documentation of these properties and the sensor performance. Ultimately, there will be development of proposals to apply the T-TDR to address research questions such as for containerized root zones relating to the air-filled pore space maintained under reduced gravity conditions. There are also many applications looking into the gas diffusion into and out of soils considering soil/microbial respiration.It is noteworthy to state that the successful operation of the prototypes does not imply that the device can be commercialized. Several other areas must be proven including a cost-effective manufacturing process in addition to sensor robustness under a variety of environmental conditions, wet/dry, freeze/thaw, and longevity of the sensor. All of these potential problems must be overcome prior to tooling up a process to manufacture the device. The cost of overcoming these obstacles and of tooling the processes for manufacturing the product is expensive and time consuming, leading to the possibility of a multi-year investment in these activities.2.2. Quantifying near-surface processes with instruments and analysesWe will continue collaboration with AZ and colleagues in China to establish improved surface and near-surface determination of soil moisture related to remote sensing. Previous efforts yielded a TDR array, which has the potential for mm-scale resolution of soil moisture with depth in the near surface. We will also work to develop surface probe(s) capable of matching the depth sensing of satellite bands. This could include robot devices that map the surface autonomously.We (UT, Poland, China) intend to pursue development of frequency-domain dielectric permittivity spectra using network analyzer and other instrument-based approaches to extract soil-specific information including water content, texture, solution ion concentration and other advanced determinations of soil properties. We will emphasize the possibility of field instruments using miniaturized vector network analyzer devices coupled with our own probes. There may be commercial potential for such devices once they are developed and demonstrated to provide novel information from soils and other porous materials.Objective 3. To integrate scale-appropriate methods to improve decisions of soil and water resources.We will work to employ over 200 soil moisture measurements across the state of Utah to develop a soil moisture map and products derived therefrom to better inform state, federal and private agencies regarding the state's soil water situation. The high-resolution map of root-zone soil moisture will improve understanding and prediction of flood, fire and drought conditions across the state. The access to data has been developed using internal grant funding, and includes 3 nodes on Utah's High Performance Computing Network. A statistical kriging and analysis algorithms is being developed to for quality control purposes and to establish a grid of soil moisture values from which to derive the soil moisture map and other products. This includes the goal to provide soil moisture analysis resources for irrigated agriculture at the farm-level. This work is in collaboration with the Utah Climate Center who will house the computing resource and resulting web-based products.