CLIMATE-SMART STRATEGIES OF WATER MANAGEMENT - COVER CROP SYSTEM TO ENHANCE PRODUCTIVITY, GREENHOUSE GAS MITIGATION, AND SOIL HEALTH IN RICE PRODUCTION

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: ACTIVE
• Funding Source: AFRI COMPETITIVE GRANT
• Reporting Frequency: Annual
• Accession No.: 1030298
• Grant No.: 2023-67019-39722
• Cumulative Award Amt.: $649,957.00
• Proposal No.: 2022-09788
• Project Start Date: Jun 1, 2023
• Project End Date: May 31, 2026
• Grant Year: 2023
• Program Code: [A1451]- Renewable Energy, Natural Resources, and Environment: Agroecosystem Management

Recipient Organization
LOUISIANA STATE UNIVERSITY
202 HIMES HALL
BATON ROUGE,LA 70803-0100

Performing Department
(N/A)

Non Technical Summary
Rice production faces increasing concerns of freshwater shortages due to the salinization of water and drought events. Besides the concerns over freshwater scarcity, reducing GHG is another challenge in rice production. Recently, a great interest has turned to rice produced in furrow-irrigated fields or row rice in the southern region of the U.S. However, furrow-irrigated rice has generally shown similar or even low yields as compared to traditional delayed continuous flooding rice production, likely due to increased nitrogen (N) loss. Research showed that cover crops and N inhibitors/stabilizers have been shown to enhance nutrient cycling (especially N), suppress weeds, reduce soil erosion, and mitigate GHG emissions. To investigate the influence of the furrow-irrigated rice combined with winter cover crop in the agroecosystem, an issue listed in Program Priority Area A1451, we proposed a three-year study with four specific objectives: 1) To quantify and compare the agronomic benefits of the furrow-irrigated rice-cover crop production system, 2) To determine and evaluate the impacts of furrow-irrigated rice-cover crop production system on the soil health parameters, 3) To quantify and assess GHG reduction of the furrow-irrigated rice-cover crop production system, 4) Modeling approaches to evaluate the GHG emissions and scoring soil health parameters. We will conduct a field experiment at Rice Research Station in LSU AgCenter to investigate the effectiveness of management in mitigating GHG emissions and improving soil health. Additionally, we will simulate and scoring soil health parameters using the DNDC model and the multivariate statistical approaches/structural equation model.

Animal Health Component

70%

Research Effort Categories

Basic

20%

Applied

70%

Developmental

10%

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
102	0210	1070	70%
132	0430	1060	30%

Knowledge Area
102 - Soil, Plant, Water, Nutrient Relationships; 132 - Weather and Climate;

Subject Of Investigation
0430 - Climate; 0210 - Water resources;

Field Of Science
1060 - Biology (whole systems); 1070 - Ecology;

Keywords

cover crop

dndc model

greenhouse gas emission

rice farming.

soil health

water management

Goals / Objectives
Our long-term goal of this proposed project is to develop and improve a more agronomically flexible and environment-friendly rice cropping system by integrating furrow-irrigated rice and cover crop production. It is expected that this integration will improve synergies among major ecosystem services of rice agroecosystems.Our specific objectives are1) To quantify and compare the agronomic benefits of furrowirrigated rice-cover crop production system with the common delayed flood rice production Project Narrative 3 system under different nitrogen fertilizer management, 2) To determine and evaluate the impacts of furrow-irrigated rice-cover crop production system on soil nutrient and carbon cycling as well as general soil health parameters, 3) To quantify and assess GHG reduction of furrow-irrigated rice-cover crop production system relative to the common delayed flood rice production system, 4) Modeling approaches to evaluate the GHG emissions and scoring soil health parameters under furrow-irrigated rice-cover crop production system and the common delayed flood rice production system.

Project Methods
Approach for addressing Objective 1: To quantify and compare the agronomic benefits of furrow-irrigated rice-cover crop production system with the standard delayed flood rice production system under different nitrogen fertilizer management.Field experiments will be conducted in a Crowley silt loam textured soil at LSU Agricultural Center Rice Research Station - South Unit, Crowley, Louisiana, to accomplish Objective 1. A split-plot design with two water management practices, namely: 1) delayed flooding (conventional, current practice) and 2) furrow irrigation as main-plot treatments; and factorial of cover crop (with vs. without) and N application methods (one single application vs. two-split application and with vs. without N stabilizers) as sub-plots. For cover crops with stabilized N, only one-time N fertilizer application with stabilizer is considered since the degradation of the cover crop would start earlier. A mixture of Austrian winter pea (seeded at 21 lbs/A) and cereal rye (seeded at 24 lbs/A), representing a 70:30 percent ratio of total seeding rates recommended for the region, will be used as cover crop treatment plots. The mixture of cover crops is expected to provide N and organic matter inputs to furrow-irrigated rice production. The cover crop will be planted in September and terminated four weeks before rice planting in the March of the following year. The amount of water used for each system will be recorded for each growing season.Approach for addressing Objective 2:To determine and evaluate the impacts of furrow-irrigated rice-cover crop production system on soil nutrient and carbon cycling and general soil health parameters.This objective attempts to assess the primary supporting services of rice agroecosystems as facilitated by the furrow-irrigated rice-cover crop system instead of the delayed continuous flooding rice system.1. Nutrient dynamics and availabilityDue to the high mobility and multi-pathway of potential loss, soil, and fertilizer N use efficiency will be evaluated using15N-labeledN -labeled urea. In doing so,15N labeled urea (enriched) will be obtained from Sigma-Aldrich, mixed with regular urea, and applied to selected treatment plots using a procedure described by Follett (2001). Microplots equivalent to 1/3 of the standard plot size from each main water treatment plot will be used for this part of the study. This study will be conducted in the first year of the study. Plant samples will be collected at harvesting, and grain and straw samples will be analyzed for total and labeled N. Based on the dilution of added15N in the plant samples, the contribution of soil and fertilizer urea-N sources to plant uptake under different treatments will be calculated as FN=100 (An-Ac)/(Ao-Ac) and SN=100-FN, where FN is the percentage of N derived by the plant from the labeled urea-N; SN is the percentage of N derived by the plant from the native soil; Anis atom%15N in the plant samples obtained from plots receiving labeled urea-N; Acis atom%15N in the control plot, where no N was applied, and Ao= atom% N in the labeled fertilizer N.For non-N nutrient elements, use efficiency will be evaluated based on differences between initial and final Mehlich III soil testing values and above-ground biomass and grain content, as well as the amount of nutrient added (based upon soil testing data of initial field site evaluation).2. Total, aggregate fraction, and molecular composition carbon characterizationBoth total C and C associated with different aggregate fractions will be determined. Genuine C will be determined using a C/N analyzer based on the soil collected from Objective 2. Field moist soils under other water management cover crop treatments will be collected and passed through an 8-mm sieve and air-dried for aggregate fractionation. Each ground will be separated into four different aggregate fractions (> 2mm, 2-0.25 mm, 0.25-0.053 mm, < 0.053mm) using a modified wet sieving procedure (Six et al., 1999), which has been set up in the PI's lab.3. Microbial community size and structureSoil microbial community size will be evaluated by determining total microbial biomass C (MBC) using the chloroform fumigation-extraction methods described by Vance et al. (1987). Natural organic C in extracts will be selected via a C/N analyzer (Shimadzu Model TOC-CPH, Japan). The difference between fumigated and non-fumigated is equivalent to the C associated with the microbial community.4. General soil health parametersOther general soil health parameters will also be determined. For physical attributes, soil bulk density will be measured by collecting multiple cores of known volume from different irrigation schemes. Aggregate stability will be measured using an aggregate separator on air-dried 2-mm sieved soil samples. Samples are oscillated in water before repeating the process in a sodium hexametaphosphate solution. Water-stable aggregates will be determined by the difference between those dispersed by the sodium hexametaphosphate solution and those scattered by water and the remaining sand particles. Soil active C will be determined using a spectrometer after reacting with potassium permanganate solution (Weil et al., 2003). For biological attributes, CO2burst respiration will be determined based 24 hr incubation of air-dried samples with NaOH traps followed by titrating with a known concentration of HCl (Haney et al., 2008). Soil enzyme activity of β-glucosidase and α-galactosidase for C cycling and β-Glucosaminidase for N cycling will be determined using NRCS recommended soil health procedures (Stott, 2019). These general parameters will allow the comparison of concerned rice agroecosystems with others published in the literature.Approach for addressing Objective 3: To quantify and assess GHG reduction of furrow-irrigated rice-cover crop production system relative to the standard delayed flood rice production systemGreenhouse gas fluxes will be monitored periodically from the beginning until the harvest of each growing season from the experimental plots described above (Objective 1). In doing so, gas fluxes will be collected using diffusion chambers, as defined by Lindau et al. (1991). The base unit of rooms will be transparent Plexiglas (30 x 30 x 30 cm). The removable diffusion chambers (top phase) will also be constructed of the same dimension as Plexiglas, containing a 12-volt fan mounted to the inside. At each time of collection, a 15 ml sample will be withdrawn from the top chambers using a 20 ml gas-tight syringe at 0, 30, and 60 minutes, respectively, and stored in vials, which are vacuumed before analysis.Approach for addressing Objective 4: Modeling approaches to evaluate the GHG emissions and scoring soil health parameters under furrow-irrigated rice-cover crop production systemand the standard delayed flood rice production system.The DNDC model will be adopted in this study to quantify GHG emission, C and N cycles, irrigating water management, cover crop residue management, and soil health parameters such as soil organic carbon (SOC) contents, tillage option, fertilizer application, etc. under different rice management conditions (Li et al., 2014). To run the DNDC model (V. 9.5), independent data from parameters, such as climate, soil type, crop parameters, and farm management practices, are required to simulate GHG emission, carbon and nutrient balance, and crop yield. The climate data will be obtained from the weather station at the Rice Research Station, LSU AgCenter, and regional climate station (climate datasets available from National Centers for Environmental Information:https://www.ncdc.noaa.gov/). Default values of other soil inputs will be used, and crop and farming management practices will be taken from the field operation records.

Progress 06/01/24 to 05/31/25

Outputs
Target Audience: The primary target audience who are directly involved in rice production: 1. Smallholder Farmers and Large-Scale Rice Growers are required to use practical, low-cost, and scalable water-saving techniques (e.g., Alternate Wetting and Drying - AWD) and require training, incentives, and access to tools or infrastructure. 2. Extension Agents act as the bridge between researchers and farmers. Thus, we reached out to disseminate climate-smart practices effectively. Secondary Target Audience (Supportive Stakeholders): 3. Policymakers and government agencies were the target audience for disseminating climate-smart practices effectively because they could develop supportive policies, subsidies, and frameworks for adoption and influence water governance and climate adaptation strategies. 4. Researchers and academics were the target audience because the findings can be communicated to farmers. This audience will develop, test, and refine climate-smart practices. 5. Agribusinesses and input suppliers who provide equipment, seeds, fertilizers, and irrigation tools were the audience. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?During this reporting period, we successfully showcased our project at both international and local conferences, with the following results: 1. On December 9, we participated in the project directors meeting for the Sustainable Agroecosystems initiative held in Austin, Texas. During the meeting, we had the opportunity to present our progress on the project. Our presentation was titled "Climate-Smart Strategies of Water Management: Implementing Cover Crop Systems to Enhance Productivity, Mitigate Greenhouse Gases, and Improve Soil Health in Rice Production." In our discussion, we highlighted the innovative approaches we are employing to address crucial environmental challenges while promoting sustainable practices in agriculture. 2. We had the opportunity to participate in the 2024 ASA-CSSA-SSSA International Annual Meetings held from November 10 to 13 in San Antonio, Texas. During this esteemed gathering, we presented our research on a comparative study of biochars produced through thermal carbonization and hydrothermal carbonization. Our presentation focused on their impact on crop production, greenhouse gas (GHG) emissions, and the distinct characteristics of each biochar type. The conference provided a valuable platform for sharing insights and collaborating with fellow researchers in the field. 3. We had the opportunity to attend the 2025 Rice Technical Working Group (RTWG) meeting, held from February 17 to 20 in New Orleans, Louisiana. During this event, we shared our insights and experiences regarding effective water management practices that we've implemented in Northwest Louisiana. Engaging with fellow participants, we aimed to contribute to the dialogue on sustainable agricultural practices and the challenges faced in rice production. 4. On February 28, 2025, we proudly showcased our innovative rice project at the "Soil Health and Cover Crops Field Day" held at the Red River Research Station, LSU AgCenter. The event provided a vibrant platform for demonstrations and discussions, allowing us to highlight the benefits and advancements of our research in sustainable rice cultivation. How have the results been disseminated to communities of interest?The target audience consists of small and medium rice farmers who are typically located in areas with traditional flooded paddy systems. They often encounter challenges such as water scarcity, rising input costs, and the necessity to increase yields sustainably. This group plays a crucial role in the implementation of furrow irrigation and alternative water management techniques, such as Alternate Wetting and Drying (AWD). The LSU AgCenter extension personnel received training on field techniques to provide effective training and technical support. They played a crucial role in promoting the adoption of improved practices. It is essential for them to have a solid understanding of how water-saving techniques influence both productivity and environmental impacts. Policy makers and government agricultural officers play a crucial role in shaping agricultural policies and water use regulations. By providing them with data on the environmental and economic benefits of furrow irrigation, as well as the potential for reducing greenhouse gas emissions, we can encourage the development of supportive policies and subsidies or the inclusion of these practices in climate-smart agriculture programs. Researchers focused on environmental and climate change were particularly concerned about the environmental impact of rice cultivation, especially regarding methane emissions. They can promote practices such as furrow irrigation through climate action programs and support training and incentive models for farmers. Companies providing irrigation equipment, seeds, and soil/water monitoring tools were targeted to understand the market potential for products designed for furrow irrigation and water-saving practices, which are critical for business development. Researchers and students in the fields of agronomy, irrigation science, soil science, and climate-smart agriculture were engaged in developing and validating alternative methods. The findings based on scientific knowledge were shared with these audiences through the Red River Research Station Field Day, as well as through informal educational programs that included field tours, laboratory tours, internships, workshops, extension activities, and outreach efforts. What do you plan to do during the next reporting period to accomplish the goals?This year, we implemented an enhanced field setup aimed at optimizing our agricultural practices, with a particular emphasis on effective water management techniques. Additionally, we established a system for collecting greenhouse gases, enabling us to monitor the impact of these treatments on reducing emissions of methane (CH4) and nitrous oxide (N2O). This comprehensive approach will help us better understand and mitigate the environmental effects of our farming practices.

Impacts
What was accomplished under these goals? 1. The mixed cover crop consisted of 70% winter pea and 30% winter rye, applied at a rate of 100 pounds per acre on December 12, 2024, prior to planting the main crop. The non-flooded furrow irrigated rice system enhances water use efficiency and reduces soil degradation compared to continuous flooding. Water is applied in furrows rather than continuously flooding fields, significantly reducing water input. However, we have to continue investigating for crop yields. This year, we will conduct furrow irrigated rice systems to maintain rice yields similar to those of delayed flooded rice systems. 2. The gas collection chambers were designed to assess greenhouse gas emissions in rice fields under diverse treatment conditions. Preliminary data suggest that the furrow-irrigated rice system contributes to a reduction in methane (CH?) emissions, which is a positive finding worth considering in our ongoing research. 3. The furrow-irrigated rice with cover crop system has shown promise in conserving water, improving soil quality, lowering greenhouse gas emissions, and maintaining competitive yields compared to the delayed flood system, all while adding agronomic flexibility and environmental sustainability. 4. Summarize that the innovative approach of using furrow irrigation for rice cultivation, complemented by the integration of cover crops, has demonstrated significant potential in various key areas. This method not only conserves valuable water resources but also enhances soil health. In addition, it has been shown to reduce greenhouse gas emissions, contributing positively to environmental sustainability. Remarkably, this system maintains competitive crop yields when compared to the traditional delayed flood irrigation method. Furthermore, it provides farmers with greater agronomic flexibility, allowing for a more adaptive and resilient farming strategy that aligns with sustainable agricultural practices.

Publications

• Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Jeon H.J., D. Kim, F.B. Scheufele, K.S. Ro, J.A. Libra, N. Marzban, H. Chen, C. Ribeiro, C.Y. Jeong*. 2024. Occurrence of Polycyclic Aromatic Hydrocarbons (PAHs) in Pyrochar and Hydrochar during Thermal and Hydrothermal Processes. Agronomy. 2024, 14, 20240.
• Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Ferdush J., C.Y. Jeong*, H.J. Jeon, J. Wang, K. Ro, X. Zhang, M.S. Lee. 2024. Assessing the long-term effects of conservation agriculture on cotton production in Northeast Louisiana using the denitrificationdecomposition model. Agrosystems, Geosciences & Environment, 7, 20514.
• Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Chen, H., T. Shin, B. Park, K. Ro, C.Y. Jeong, H.J. Jeon, P-L, Tan. 2024. Coupling hyperspectral imaging with machine learning algorithms for detecting polyethylene (PE) and polyamide (PA) in soils. Journal of Hazardous Materials 471 (2024) 134346.
• Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Shin, J.D., D.K. Lee, C.K. shim, J.H. Nam, S.W. Park, S.G. Hong, J-S. Song, C.Y. Jeong*.2024. Nutrient release pattern and mitigation of N2O emissions under the application of activated poultry manure compost biochar with organic resources. Environmental Pollution 356: 124250.
• Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Farru, G., F.B. Scheufele, D.M. Paniagua, F. Keller, C.Y. Jeong, D. Basso. 2024. Business and Market Analysis of Hydrothermal Carbonization Process: Roadmap toward Implementation. Agronomy. 2024, 14, 541. https://doi.org/10.3390/agronomy14030541.
• Type: Peer Reviewed Journal Articles Status: Published Year Published: 2024 Citation: Chau, H.D., G. Cappai, J.W. Chung, C.Y. Jeong, B. Kulli, F. Marchelli, K.S. Ro, and S. Rom�n. 2024. Research Needs and Pathways to Advance Hydrothermal Carbonization Technology. Agronomy, 2024, 14, 247.

Progress 06/01/23 to 05/31/24

Outputs
Target Audience:Local producers, State agencies, County agencies, and Academic scientists via field days, local, state, and national meetings, Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals?We will report the following three objectives: Objective 1: To quantify and compare the agronomic benefits of furrow-irrigated rice-cover crop production system with the common delayed flood rice production system under different nitrogen fertilizer management, Objective 2: To determine and evaluate the impacts of furrow-irrigated rice-cover crop production system on soil nutrient and carbon cycling as well as general soil health parameters, Objective 3: To quantify and assess GHG reduction of furrow-irrigated rice-cover crop production system relative to the common delayed flood rice production system,

Impacts
What was accomplished under these goals? To accomplish objective 1, "To quantify and compare the agronomic benefits of furrowirrigated rice-cover crop production system with the common delayed flood rice production," we planted cover crop, 70 % of winter pea, and 30 % of winter cereal rye, in the Red River Research Station on November 20, 2023. We will terminate the cover crop two weeks before rice planting.

Publications