Location: Coastal Plain Soil, Water and Plant Conservation Research
2023 Annual Report
Objectives
1. Develop and test improved tillage, cover crops, and biomass management to enhance soil health and resiliency and improve long-term agricultural sustainability and productivity in the Southeastern Coastal Plain.
2. Develop manure treatment and handling systems that minimize the emissions of greenhouse gases, antimicrobial resistance genes, odors, nutrients, and pathogens to improve soil health and water quality outcomes.
2.A. Develop new, affordable treatment technologies for removal/recovery of manure nutrients from swine, poultry, and dairy operations and industrial/municipal wastes.
2.B. Conduct multiscale assessment of the impact of manure treatment and nutrient management systems on agricultural ecosystem services for soil conservation and water quality protection.
2.C. Increase the value of agricultural residuals using hydro- and thermal technologies.
2.D. Develop improved techniques for quantifying ammonia deposition near livestock production sites.
3. Develop biostimulants and other soil amendments and assess their ability to improve soil health, nutrient cycling, and soil fertility and resiliency.
3.A. Develop and assess microbial inoculants and other soil amendments for their ability to enhance revegetation and improve drought resistance in remediated and degraded soils.
3.B. Develop biochar and hydrochar applications to improve their use in agricultural and non-agricultural settings.
Approach
New management practices and treatment technologies are required to help crop and animal producers increase soil productivity and health; reduce unwanted atmospheric emissions, excessive nutrients, and pathogens; and improve affordability of animal waste treatment. To meet these needs, we aim to develop in this project: i) knowledge of the impact of crop systems and novel soil amendments on the soil ecosystem and nutrient and carbon cycling; ii) new manure treatment technologies; iii) model-based approaches to evaluate nutrient and gas emission reduction strategies; iv) management strategies to reclaim degraded soils; v) management practices to reduce pathogens and antimicrobial resistance genes in agricultural wastes; and vi) knowledge of and metrics for properties that make a soil more productive. The project has three objectives. Improved tillage, cover crops, and biomass management will be developed to enhance soil health and resiliency and improve long-term agricultural sustainability and productivity in the Southeastern Coastal Plain. Innovative manure treatment systems will be developed to minimize greenhouse gas emissions, and reduce antimicrobial resistance genes and pathogens, odors, and excess nutrients, to improve soil health and water quality outcomes. The manure treatment technologies include recovery of ammonia using gas-permeable membranes, enhanced deammonification treatment, and engineered biochar and hydrochar systems to valorize agricultural residuals. Manure management's beneficial impact will be assessed using multiscale models, and improved techniques will be used to assess ammonia emissions from manure, including deposition near livestock operations. Biostimulants and other soil amendments will be investigated for their ability to improve soil health, nutrient cycling, soil fertility, and resiliency. Research methods include laboratory, pilot-scale, and field-scale experiments using modern analytical equipment. Research products will advance the state-of-the-science for more effective conservation and management of soil resources, innovative animal waste treatment technologies as environmentally safe alternatives to traditional land application, and guidelines for beneficial byproduct utilization.
Progress Report
Soybean and cotton biomass samples were collected at the end of the 2022 growing season, processed, and analyzed for total carbon and nitrogen. Cotton lint and soybean grain yields were determined and compiled for the 2022 season. Following the cash crops harvest, carinata was planted in the plots in December 2022 as a double crop. Unusually extreme cold temperatures (-9.4 °C) 3-weeks after planting carinata resulted in a significant (>80%) stand loss. To compensate, a four-species winter cover crop mixture was established in January 2023, in place of carinata. Cover crop biomass yield data were collected before their termination in April 2023 and are being analyzed for nutrient content. (Obj 1a)
An automated soil carbon dioxide (CO2) flux system (LiCOR LI-8100A) was installed, and daily CO2 measurements are being recorded. Soil CO2 flux data from the first two years of the study have been summarized and are pending further analysis. (Obj 1b)
Soil samples were collected immediately following cotton and soybean harvest in Fall 2022, and before cover crop termination in spring 2023. Soil samples have been processed and analyzed for chemical properties including pH and electrical conductivity, soil carbon and nitrogen pools, as well as other essential nutrients including soil P. (Obj 1c)
Soil enzyme analyses for beta-glucosidase and acid phosphatase, are in progress. Fluorescein diacetate activity assays to measure overall microbial activity are also underway. (Obj 1d)
Cooperated in a CRADA with commercial partner to pilot test de-ammonification of anaerobically digested swine wastewater and water recycling into the barns to improve the health of the animals. The testing done with confined piglets and replicated five times showed significant improvement in the rate of gain of the animals with nitrified water under the pits. (Obj 2a.1)
Development of improved treatment methods for recovery of N and P from manure using gas-permeable membranes. Conducted batch treatment experiments using electrochemical methods and gas-permeable membranes to recover ammonia from liquid swine manure. (Obj 2a.2)
Testing of phosphorus and protein extraction from manure using acid precursors. Testing was done to evaluate for the first time the use of lactose waste as an acid precursor to extract phosphorus from dairy manure. (Obj 2a.3)
Conducted batch treatment experiments using selected municipal sludge acid rates for phosphorus extraction followed by phosphorus recovery trials after acid extraction (Obj 2a.4)
Revisited the updated Intergovernmental Panel on Climate Change (IPCC) method on emissions from livestock and manure management for estimating methane emission from uncovered swine concentrated animal feeding operation (CAFO) waste treatment lagoons in North Carolina. Applied method to quantify and upscale methane emission reduction of a solid-liquid separation system. In addition, testing a machine learning (ML) filtering algorithm to retrieve swine CAFO lagoon's properties from aerial red, green, and blue (RGB) and near infrared (NIR) images. (Obj 2b)
Performed thermogravimetric pyrolysis kinetic analyses for selecting optimal co-pyrolysis temperature and duration for cotton gin trash and plastic wrapping film samples. Made 3 kg plastichar from co-pyrolyzing cotton gin trash and the plastic wrapping film and sent to Louisiana State University collaborator for evaluating its effectiveness in amending soils for improved tomato yield and reduction of environmental pollution (MTA# 18201) (Obj 2c.1)
Determination of pathogen kill rates, and degree of deoxyribonucleic acid (DNA) degradation using Escherichia coli as a proxy organism in poultry mortality studies, under different hydrothermal carbonization treatment (HTC) regimens has been completed. Chemical analyses of gas, liquid, and solid products, as well as anaerobic digestion of hydrothermal carbonization process liquid, are planned. (Obj 2c.2)
A cooperating swine producer near Ames, Iowa, was identified, and an agreement was reached to allow on-farm ammonia concentration measurements. Agreements with farmers downwind of the farm to setup sensors to measure concentration and wind turbulence were also secured. An agreement with a landowner to obtain upwind/background measurements was delayed, but a landowner has been identified and an agreement is being pursued. Measurements will begin after this final agreement is secured. (Obj 2d)
A second year of microbial inoculant was prepared in Florence, SC, shipped to Webb City, MO, and applied to plots established the prior year. Samples were collected in November 2022 and April 2023, and DNA was extracted to monitor potential changes to the microbial communities and function within the established plots. Plans were made between ARS, the US Environmental Protection Agency, Colorado State University collaborators, and Webb City, Missouri, officials for site maintenance and Fall 2023 sample collection. (Obj 3a.1)
Plots were re-established for a second year, and microbial inoculants – a combination of microbial and arbuscular mycorrhizal fungi – were applied. Sensors to monitor moisture were calibrated inserted at 5 and 25 cm depths to monitor plant available water. Early season soil samples have been collected, and are pending analysis, to monitor microbial activity prior to start of the drought stress portion of the study. (Obj 3a.2)
Inactivated, magnesium-activated, and iron-activated poultry litter- and pine chip-derived biochars were produced at pyrolysis temperatures ranging from 500-900°C. We collected two soils with high concentrations of soluble P from Maryland and Delaware. Activated and non-activated swine-manure based hydrochars are currently evaluated for its effectiveness in sorbing P. (Obj 3b.1)
Inactivated and manganese-activated poultry litter- and pine chip-derived biochars were produced at pyrolysis temperatures of 500 and 700°C. Laboratory batch experiments were completed to determine the sorption of cadmium, copper, lead, nickel, and zinc by the biochars as a function of solution pH, heavy metal concentration, and time. Activated and non-activated manure-based hydrochars are currently evaluated for their effectiveness removing heavy metals via sorption. (Obj 3b.2)
Accomplishments
1. Reduction of methane emissions from swine manure management using solid-liquid separation. Typical swine manure management causes substantial methane emissions. Retrofitting of anaerobic lagoons with solid-liquid separation modules could enable methane avoidance strategies. However, quantitative emissions reduction estimates are needed for effective methane emission reduction programs. ARS researchers in Florence, South Carolina, quantified methane emission reductions using two full-scale swine waste treatment systems: 1. the conventional lagoon-based swine waste treatment system (baseline scenario), and 2. the lagoon-based system retrofitted with a solid-liquid separation module (project activity). Results showed that methane emissions are reduced by 65.9% with the solid-liquid separation treatment: average annual methane emissions per 1000 kg live pig weight were 332.2 kg and 113.2 kg in scenarios 1 and 2, respectively (20.3 and 6.9 kg methane per finishing pig per year). A multiscale evaluation for the North Carolina region showed hotspots of methane emissions at county, watershed, and regional levels. This new information could help to effectively attack the methane emission problem from manure management in the region.
Review Publications
Sohoulande Djebou, D.C., Szogi, A.A., Novak, J.M., Stone, K.C., Martin, J.H., Watts, D.W. 2023. Instream constructed wetland capacity at controlling phosphorus outflow under a long-term nutrient loading scenario. Modeling Earth Systems and Environment. https://doi.org/10.1007/s40808-023-01763-w.
Sohoulande Djebou, D.C., Szogi, A.A., Novak, J., Stone, K.C., Martin, J.H., Watts, D.W. 2022. Long-term nitrogen and phosphorus outflow from an instream constructed wetland under precipitation variability. Sustainability. https://doi.org/10.3390/su142416500.
Padilla, J.T., Selim, H.M., Gaston, L.A. 2022. Modeling the competitive sorption and transport of Ni(II) and Zn(II) in soils: Comparing two multicomponent approaches. Journal of Contaminant Hydrology. 252. Article 104108. https://doi.org/10.1016/j.jconhyd.2022.104108.
Padilla, J.T. 2023. Simple approaches to modeling pH-dependent and multicomponent sorption of Ions by variable-charged minerals. Soil Science Society of America Journal. https://doi.org/10.1002/saj2.20555.
Bernal, M.P., Vanotti, M.B. 2023. Insights into waste management in agroecosystems. Frontiers in Sustainable Food Systems. 7. Article 1176007. https://doi.org/10.3389/fsufs.2023.1176007.
Vanotti, M.B. 2023. Circular economy approaches in the livestock waste area. Food and Fertilizer Technology Center (FFTC) Journal of Agricultural Policy. 4:48-54. https://doi.org/10.56669/ANBP7094.
Farru, G., Libra, J., Ro, K.S., Cannas, C., Cara, C., Muntoni, A., Piredda, M., Cappai, G. 2023. Valorization of face masks produced during COVID-19 pandemic through hydrothermal carbonization (HTC): a preliminary study. Sustainability. 15(12):9382. https://doi.org/10.3390/su15129382.
Marzban, N., Libra, J.A., Rotter, V.S., Ro, K.S., Paniagua, D.M., Flornenko, S. 2023. Changes in selected organic and inorganic compounds in hydrothermal carbonization (ATC) process liquid while in storage. ACS Omega. 8(4):4234-4243. https://doi.org/10.1021/acsomega.2c07419.
