Source: PENNSYLVANIA STATE UNIVERSITY submitted to NRP
TO WHAT EXTENT WILL IMPROVED SOIL CARBON AFFECT TRANSPIRABLE SOIL WATER AND ALLEVIATE CROP WATER STRESS ACROSS CONTERMINOUS U.S.?
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1030558
Grant No.
2023-67019-39837
Cumulative Award Amt.
$287,212.00
Proposal No.
2022-09270
Multistate No.
(N/A)
Project Start Date
Aug 1, 2023
Project End Date
Sep 23, 2024
Grant Year
2023
Program Code
[A1401]- Foundational Program: Soil Health
Recipient Organization
PENNSYLVANIA STATE UNIVERSITY
408 Old Main
UNIVERSITY PARK,PA 16802-1505
Performing Department
(N/A)
Non Technical Summary
Soil carbon is responsiblefor a sizeable fractionof greenhouse gas emissions mitigation potential in agriculture. Practical ways to buildsoil carbon such as a wide range ofclimate-smartpractices are supportedby government programs and carbon markets. Although the primary major outcome is greenhouse gas emissions mitigation, their widespread adoption is also driven by the resultingsoil healthbenefits, usually referred to as co-benefits. Soilinfluence on plant water relationships is described bysoil properties such as saturation point,field capacity, permanent wilting point, and available water capacity.It is generally accepted that higher soil organic carbonimproves available water capacity, but this observation is of limited use to producers when they intendto visualizethe tangible benefits they can expect. Also, there is little scientific data onwhether increased available water capacity is negligible or sufficiently large for any practical benefits on farm water and climate resiliency. A given increase in available water capacity can result in vastly different outcomes in terms of crop water availability, crop water stress, and irrigation requirements, and these outcomes have not been evaluatedfor U.S. croplands. This project will address this absence of quantitative understanding of producer-facing hydrological impacts of soil carbon sequestration, significantly improving the state of knowledge and effective communication of soil health co-benefits.OBJECTIVES:The overall project goal is to understand, quantify, and communicate the impacts of realistically achievable improvements in soil organic carbonon agricultural water budget and producer-level risk and resiliency across U.S. agricultural ecosystems.The goal will be accomplished bythe following objectives: (1) Quantify change in root-zone available water capacity resulting from realistically achievable soil organic carbon increase across aridity regimes in the United States; (2) Determine site-specific impacts of soil organic carbon increase onsoil water availability, crop water use and stress, and irrigation requirements; and (3) Evaluate spatial and temporal drivers of soil organic carbon-causedcrop and water resiliency.APPROACH:Objectives will be carried out by simulating soil water retention properties and critical agrohydrological components using approaches that are sensitive to soil health indicators. The approach will be make use of publicly available datasets, modeling frameworksand knowledge on relationships among soil characteristics, hydrology, and climate.We will compile estimates of realistically achievable soil organic carbon increase upon adoption of major climate-smart practices, including conservation tillage, cover crops, biochar addition, prescribed grazing, or combination of these practices. We will rely on recent literature synthesis for mean soil organic carbon increase with uncertainty estimates.We will translate baseline and improved soil organic carbon across United States into baseline and improved available water capacityacross the United States using predictive functions of soil properties. Finally, we will determine the sensitivity of plant usablesoil water and crop water stress to realistically achievable soil organic carbon increase using soil water budget simulations.Utimately, the deliverables from the project will lead to improved understanding of the relationships between soil organic carbon, soil hydrology, and crop resiliency across diverseenvironments.Large-scale quantitative evidencewill enhance communication of incentives for adoption of soil health practices by producers.
Animal Health Component
20%
Research Effort Categories
Basic
60%
Applied
20%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
1020110205025%
1110430206025%
1320420207025%
4050210202025%
Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 111 - Conservation and Efficient Use of Water; 132 - Weather and Climate; 405 - Drainage and Irrigation Systems and Facilities;

Subject Of Investigation
0420 - Weather; 0110 - Soil; 0430 - Climate; 0210 - Water resources;

Field Of Science
2070 - Meteorology and climatology; 2020 - Engineering; 2050 - Hydrology; 2060 - Geography;
Goals / Objectives
The overarching goals of the project are to (a) understand whether and how much will improved soil organic carbon affect the amount of transpirable soil water in the crop root zone, the degree to which crops experience water stress, and irrigation water requirement upon adoption of climate-smart practices; and (b) how do these possible benefits change under different soils, crops, regions, and weather conditions. The goals will be achieved using three objectives:Objective #1: Quantify change in crop root zone available water capacityresulting from realistically achievablesoil organic carbon increase across conterminous U.S.Objective #2: Determine site-specific impacts of soil organic carbon-driven AWC increase on soil water availability, crop water use and stress, and irrigation requirements.Objective #3: Evaluate spatio-temporal drivers of soil organic carbon-driven agrohydrological benefits
Project Methods
Efforts: We will conduct simulations for the following successive efforts:Quantify change in crop root zone available water capacity resulting from realistically achievable soil organic carbon increase across conterminous U.S.Determine how site-specific available water capacity increase will alter soil water budgetEvaluate how different soils, crops, and environmental conditions affect potential benefits from improvedsoil organic carbonEvaluation: We will evaluate the success of the project by ensuring key milestones are accomplished, i.e., robustness of quantitative estimates and their uncertaintiesin each of the target variables mentioned above. Also, documentation and interactive presentation of the change will ensure accessibility of findings for audiences.

Progress 08/01/23 to 09/14/24

Outputs
Target Audience:The target audience is researchers in soil hydrology and soil health, and stakeholder groups. Changes/Problems:The project is ending early due to a transfer of PD to another institution andit will be continued at the new institution What opportunities for training and professional development has the project provided?(i) Training of a Ph.D. student in soil hydrology and soil heath areas. (ii) Outcomes were incorporated into a graduate level class on "Applied Agrohydrology". How have the results been disseminated to communities of interest?An extension article:Resiliency Against Agricultural Droughts and Excess Water https://extension.psu.edu/resiliency-against-agricultural-droughts-and-excess-water. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Objective #1: Quantify change in crop root zone available water capacityresulting from realistically achievablesoil organic carbon increase across conterminous U.S. 1) Major activities completed / experiments conducted: Simulated AWC change resulting from 1-5% SOC in 1% increments for 12 unique soil texturesat contrasting aridity zones during 42 years using carbon-sensitive pedotransfer functions. 2) Data collected: Under each model run, we collected altered (improved) AWC values. 3) Summary statistics and discussion of results: Field capacity and permanent wilting points of sandy clay soil had the highest sensitivity to unit change in SOC, while silt soil was minimally sensitive. 4) Key outcomes or other accomplishments realized: Improved knowledge of how soil texture influences SOC impacts on AWC, so as to be useful to a large diversity of agroecosystems. Objective #2: Determine site-specific impacts of soil organic carbon-driven AWC increase on soil water availability, crop water use and stress, and irrigation requirements 1) Major activities completed / experiments conducted: Simulatedchange in rainfed cornwater use (ET) resulting from increase inSOC in 1% increments (within 0-5%) for 12 unique soil texturesat contrasting aridity zones during 42 years using soil water budget modeling 2) Data collected: Under each model run, we collected data on (i) how much reduction in seasonal ET was incurred due to crop water stress; and (ii) daily crop water stress factor. 3) Summary statistics and discussion of results: Greater SOC improved both metrics under all scenarios.We find that crop water stress cannot always be avoided or reduced because of increased AWC. That is because there might not be sufficient precipitation to leverage the benefit of the additional soil water storage (e.g. arid and semi-arid sites without irrigation). Similarly, during wet years in humid sites, AWC benefit may not result in significant benefits as ETc can be maintained at its optima even at lower SOC and AWC. Overall, the extent to which crop water stress will be alleviated is a complex function of soils, weather, and aridity. Thus, (i) whether SOC will result in drought resiliency outcomes and (ii) to what degree this benefit can be expected is site-year-management specific.We find that crop water stress cannot always be avoided or reduced because of increased AWC. That is because there might not be sufficient precipitation to leverage the benefit of the additional soil water storage (e.g. arid and semi-arid sites without irrigation). Similarly, during wet years in humid sites, AWC benefit may not result in significant benefits as ETc can be maintained at its optima even at lower SOC and AWC. Overall, the extent to which crop water stress will be alleviated is a complex function of soils, weather, and aridity. Thus, (i) whether SOC will result in drought resiliency outcomes and (ii) to what degree this benefit can be expected is site-year-management specific. 4) Key outcomes or other accomplishments realized: These findings improved understanding of how nuanced crop water use versus SOC relationships can be, which is a significant advance from mostly qualitative relationships understood previously. Objective #3: Evaluate spatio-temporal drivers of soil organic carbon-driven agrohydrological benefits Since this project is ending early due to a transfer and that it will be continued at PD's institution, the findings from last objective areyet to be analyzed.

Publications

  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Kukal, M. S., & Irmak, S. (2023). Can limits of plant available water be inferred from soil moisture distributions?. Agricultural & Environmental Letters, 8(2), e20113.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Gulati, D., & Kukal, M. S. (2024, July 28-31). Translating soil carbon sequestration into agrohydrological outcomes across a spectrum of aridity and soil texture. Abstract ID 2400890. [Oral presentation]. ASABE 2024 annual international meeting, Anaheim, CA, United States.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Gulati, D., & Kukal, M. S. (2024, July 14-17). Translating soil carbon sequestration into agrohydrological outcomes across a spectrum of aridity and soil texture. Paper no. 24-066. [Oral presentation]. NABEC 2024, State College, PA, United States.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2024 Citation: Gulati, D., Thorp, K. R., DeJonge, K., & Kukal, M. S. (2024) Hydrological Losses Under Increased Soil Organic Carbon and Weather Variability in Different Soil Textures [Abstract]. ASA, CSSA, SSSA International Annual Meeting, San Antonio, TX. https://scisoc.confex.com/scisoc/2024am/meetingapp.cgi/Paper/157317
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2024 Citation: Gulati, D., Thorp, K. R., DeJonge, K., & Kukal, M. S. (2024) How Does Improving Soil Structure Impact Crop Evapotranspiration and Water Stress across Soil Textures and Aridity? [Abstract]. ASA, CSSA, SSSA International Annual Meeting, San Antonio, TX. https://scisoc.confex.com/scisoc/2024am/meetingapp.cgi/Paper/157313
  • Type: Journal Articles Status: Published Year Published: 2024 Citation: Kukal, Meetpal Singh. "Relative and Unified Skill of Environmental, Edaphic, and Management Factors to Explain Crop Yield Variance Using Machine Learning." (2024): 995-1011.


Progress 08/01/23 to 07/31/24

Outputs
Target Audience:Scientific researchers; students; producers Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?The project is currently providing training to one graduate student leading these project activities in the areas of climate smart agriculture and its impacts on agrohydrology. How have the results been disseminated to communities of interest?So far, we have presented these partial findings atNORTHEAST AGRICULTURAL / BIOLOGICAL ENGINEERING CONFERENCE (State College, PA; July 2024). What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, we plan to conclude our work on rainfed crop evapotranspiration impacts and assess impacts on hydrological losses (runoff and deep percolation) under irrigated and deficit systems. We plan to author 3-4 articles that will summarize these activities to the broader community.

Impacts
What was accomplished under these goals? Major activities: The project addresses the question of whether and how much adding soil organic carbon will improve the hydrologic state of soil and water stress in crops. The outcomes will help agricultural producers to understand and quantify exactely how much crop water stress will be relieved or irrigation water use will decrease upon adopting climate-smart agricultural practices that help build soil organic carbon. This will be realized by generating quantitative knowledge on change in soil water budgets across regions with contrasting soil types and aridity. Objective 1: We simulated change in available water capacity for 12 different soil textures when soil orgnic carbon increased from 0 to 5% in 1% increments by using carbon-sensitive pedotransfer functions published recently in the literature. Objective 2: We combined outcomes of objective 1 (i.e, available water capacity under different soil textures and soil organic carbon scenarios) with a soil water budget modeling framework following standardized approaches to simulate evapotranspiration of rainfed corn crop at a site with highest production in each of the four aridity classes (arid, semi-arid, dry sub-humid, and humid) in the U.S. during 1981-2021. We determined to what degree crop water stress was relieved by tracking the deficit in actual seasonal evapotranspiration from its well-watered equivalent, as well as tracking daily crop water stress coefficient as defined by FAO-56. Major accomplishments/outcomes: While currently ongoing, our investigations so far have revealed that impacts of increasing soil organic carbon on crop water stress are highly variable by soils, aridity, and timing of precipitation combined with antecedent soil moisture. The most benefit was observed for the arid site, where the evapotranspiration deficit was the most sensitive to change in seasonal aridity index. We found that clay and sandy clay soils show the most sensitivity of evapotranspiration deficit to SOC increase, while silt soils benefit the least.

Publications

  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Kukal, M. S., & Irmak, S. (2023). Can limits of plant available water be inferred from soil moisture distributions?. Agricultural & Environmental Letters, 8(2), e20113.
  • Type: Journal Articles Status: Accepted Year Published: 2024 Citation: Kukal, M. S. (2023). Relative and Unified Skill of Environmental, Edaphic, and Management Factors to Explain Crop Yield Variance using Machine Learning. Journal of the ASABE
  • Type: Conference Papers and Presentations Status: Published Year Published: 2024 Citation: Gulati, D., Kukal, M.S. (2024) Translating Soil Carbon Sequestration into Agrohydrological Outcomes across a Spectrum of Aridity and Soil Texture. NORTHEAST AGRICULTURAL / BIOLOGICAL ENGINEERING CONFERENCE