About

Neslihan Akdeniz is associated with the Center for Digital Agriculture at the University of Illinois. The center focuses on research and development in digital and precision agriculture, including AI-driven tools, data analysis, and innovative technologies to support sustainable farming practices. The center offers various programs such as a Master’s Degree in Engineering with a concentration in Digital Agriculture, interdisciplinary collaborations, and joint seminar series with institutions like National Taiwan University. The center's initiatives include developing decision-support services like CropWizard, which utilizes generative AI to assist agricultural professionals, and projects like AIFARMS, which advance understanding of AI applications in agriculture. The center also hosts events, hackathons, and conferences to promote global perspectives on digital and smart agriculture, emphasizing transparency, trust, and technological advancement in the agricultural sector.

Research topics

• Agronomy
• Biology
• Environmental science
• Forestry
• Chemistry
• Agricultural engineering
• Animal science
• Agricultural science
• Engineering
• Environmental chemistry
• Microbiology
• Business
• Environmental engineering
• Geography
• Food science

Selected publications

• Practical Guidelines to Improve the Sustainability of Ventilation Fan Use in Agricultural Operations

  Sustainability · 2026-03-03 · 1 citations

  articleOpen accessSenior authorCorresponding

  Ventilation systems in agricultural settings are designed to deliver specific air exchange rates, which are often not achievable using natural ventilation. In this study, we analyzed 105 agricultural ventilation fans tested between 2015 and 2025 at the Bioenvironmental and Structural Systems (BESS) Laboratory, including 0.6, 0.9, 1.2, and 1.5 m diameter fans operating at static pressures ranging from 0 to 75 Pa. The main objective of the study is to develop and introduce guidelines to help select the most suitable ventilation fans to improve the sustainability of agricultural operations. Two web-based interactive calculators were developed to visualize fan performance relative to low- and high-performing fans of the same diameter. Our findings indicated that the ventilation efficiency ratio (VER) of the fans ranged from 2 to 50 m3 h−1 W−1, and larger fans consistently showed higher efficiency at typical operating pressures of 12.5 to 37.5 Pa. In general, variable-speed fans operated at 85%, rather than full capacity, achieved higher efficiency. Two cost comparison scenarios were examined. In the first scenario, the fan with a higher purchasing cost but also 35% higher efficiency resulted in a payback period of 4.1 years. In the second scenario, the difference in fan efficiencies was less than 3.5%, which did not help with recovering higher purchase costs during the 10-year analysis period. It was concluded that selecting fans solely based on purchase price can lead to higher long-term costs. To improve the sustainability of agricultural fans, VER and operating conditions need to be evaluated together and integrated into automated control strategies. Future studies can focus on integrating fans with high efficiencies into sensor-based automated ventilation control systems to quantify long-term energy savings in livestock buildings and other agricultural operations.

  PublisherOA PDFDOI

• A comprehensive review of computational modeling, data analytics, and intelligent approaches to greenhouse ventilation systems

  Smart Agricultural Technology · 2026-04-23

  articleOpen accessSenior authorCorresponding

  • Review of 1,392 greenhouse ventilation studies published from 2016 to 2025. • 460 studies applied CFD, ML, or AI to analyze greenhouse ventilation. • Natural ventilation reduces energy use but depends on wind and geometry. • CFD simulations quantify air velocity and temperature gradients. • ANN and SVM models predict greenhouse microclimate and ventilation control. Ventilation is the primary mechanism to control temperature, relative humidity, and carbon dioxide levels in greenhouses. Properly designed ventilation systems remove sensible and latent heat generated by solar radiation and crop transpiration while maintaining adequate air exchange between indoor and outdoor environments. This review synthesizes research published between 2016 and 2025 on natural, mechanical, and hybrid ventilated greenhouses, with emphasis on the increasing use of computational and data-driven approaches. In this study, a comprehensive literature search was conducted across Web of Science, Scopus, and Google Scholar. A total of 1,392 publications on greenhouse ventilation were identified, including 460 studies focusing on computational fluid dynamics (CFD), machine learning (ML), or artificial intelligence (AI). The number of studies applying ML and AI increased after 2018. The review summarizes differences among ventilation strategies. Natural ventilation offers low energy demand and simple operation, yet its effectiveness depends on greenhouse geometry and weather conditions. Natural ventilation often causes spatial variability, affecting temperature distribution. Mechanical ventilation provides more consistent environmental control when natural ventilation cannot maintain desired conditions, particularly in regions with high solar radiation. Hybrid systems combine natural and mechanical ventilation, allowing flexible operation under changing environmental conditions. Computational fluid dynamics (CFD) has become an important analytical tool for examining airflow patterns, ventilation rates, and temperature distribution across greenhouse structures. However, CFD simulations are often run under steady-state conditions that do not fully reflect the transient conditions observed in commercial-scale greenhouses. In recent studies, machine learning models, such as artificial neural networks and support vector machines, were used to predict greenhouse microclimate variables from weather data and sensor measurements, enabling predictive control of vent openings and fan operation. Future research can focus on integrating validated computational models and real-time monitoring systems to support sustainable ventilation control across diverse greenhouse environments.

  PublisherDOI

• Direct Air Emission Measurements from Livestock Pastures Using an Unmanned Aerial Vehicle-Based Air Sampling System

  Remote Sensing · 2025-09-03

  articleOpen accessCorresponding

  Quantifying air emissions from livestock pastures remains challenging due to spatial variability and temporal fluctuations in emissions due to weather conditions. In this study we used a small unmanned aerial vehicle (sUAV) equipped with real-time sensors and an air sample collection system to directly measure carbon dioxide (CO2), methane (CH4), ammonia (NH3), nitrous oxide (N2O), nitrogen dioxide (NO2), hydrogen sulfide (H2S), total volatile organic compound (VOC), and particulate matter (PM1, PM2.5, PM10) emissions across two dairy pastures, two beef pastures, and one sheep pasture in Wisconsin. Emission rates were calculated using the Lagrangian mass balance model and validated against ground-level dynamic flux chamber (DFC) measurements. UAV-based CO2 concentrations showed a strong correlation with DFC measurements (R2 = 0.86, RMSE = 21.5 ppm, MBE = +9.7 ppm). Dairy 1 yielded the highest emissions for most compounds, with average emission rates of 0.50 ± 0.28 g m−2 day−1 head−1 for CO2, 8.48 ± 2.75 mg m−2 day−1 head−1 for CH4, and 0.20 ± 0.60 mg m−2 day−1 head−1 for NH3. The sheep pasture, on the other hand, had the lowest CH4 and NH3 emission rates, averaging 0.35 ± 0.22 mg m−2 day−1 head−1 and 0.02 ± 0.05 mg m−2 day−1 head−1, respectively. Rainfall events (≥ 5 mm within five days of sampling) significantly elevated N2O emissions (0.56 ± 0.40 vs. 0.13 ± 0.17 mg m−2 day−1 head−1). Particulate matter emissions were significantly affected by forage density. PM2.5 emission rates reached 1.25 × 10−4 g m−2 day−1 head−1 under low vegetative cover. It was concluded that emissions were affected by both animal species and the environmental conditions. The findings of this study provide a foundation for further development of emission inventories for pasture-based livestock production systems.

  PublisherOA PDFDOI

• Ventilation Fans Offset Potential Reductions in Milk Margin from Heat Stress in Wisconsin Dairy Farms

  Agriculture · 2025-04-28 · 2 citations

  articleOpen access1st authorCorresponding

  Heat stress is becoming an increasing concern for dairy farmers due to elevated temperatures and wind shadow caused by rural development. Mechanical ventilation helps mitigate heat stress; however, transitioning from natural to mechanical ventilation increases operational costs. In this study, the number of days with no heat stress, as well as mild, moderate, and severe heat stress, was calculated for Madison, Wisconsin, over the past five years. Monthly milk margins were determined using all milk prices and feed costs from the Dairy Margin Coverage (DMC) program. The goal was to compare the potential reduction in milk margin coverage to the electricity costs of operating ventilation fans. The results indicated that while the five-year average milk margin reduction due to heat stress was USD 20,204 for a 600-head facility, the electricity cost accounted for approximately 42.6% of this amount. However, milk margins fluctuated annually due to volatility in milk and feed markets. For example, in 2021, the reduction in milk margins was estimated at USD 9804, while electricity costs reached USD 8574. It was concluded that in some years, when no severe heat stress occurs, the benefits of ventilation may be close to the expenses. Therefore, adhering to best management practices is critical for minimizing electricity costs while using ventilation fans in dairy operations.

  PublisherOA PDFDOI

• Assessing ventilation design of dairy buildings equipped with automated milking systems using computational fluid dynamics

  Computers and Electronics in Agriculture · 2025-08-21 · 1 citations

  articleOpen accessSenior authorCorresponding

  • CFD models were developed and validated for two full-scale AMS dairy barns. • Baffles reduced pen temperature by 4.25 % and more than doubled airflow. • Supply fans showed no airflow benefit at cow resting height (0.5 m). • AMS units placed along the side wall did not block airflow (preferred layout). • Air inlets with baffles improved airflow more efficiently than supply fans. Automated milking systems (AMS) are increasingly used in dairy production to address labor shortages while supporting cow health and milk production. However, their integration into barn layouts can restrict airflow and increase the risk of heat stress in lactating cows. In this study, we developed and validated computational fluid dynamics (CFD) models for two full-scale AMS barns to evaluate airflow and temperature distribution under different ventilation designs. Farm 1, a tunnel-ventilated barn, housed 218 lactating cows and six milking robots, while Farm 2, a cross-ventilated barn, accommodated 424 lactating cows and eight robots. The model geometry incorporated standing and lying cows, AMS units, ventilation and circulation fans, air inlets, stalls, feed alleys, and baffles. A mesh convergence test was conducted, with the final number of elements ranging from 16.7 to 21.4 million and y + values below 300. In Farm 1, replacing supply fans with an air inlet had no significant impact on temperature or airflow distribution at either cow resting or standing heights, indicating limited benefit from using supply fans, especially considering their energy consumption. Meanwhile, adding baffles reduced temperatures in the commitment pen by up to 4.25 % and increased air velocity at 0.5 m from 0.33 ± 0.2 to 0.77 ± 0.3 m s −1 (p = 0.005). In Farm 2, AMS units were placed along the side wall, and as expected, their removal had no measurable effect on temperature (≤0.2 °C difference, p > 0.05) or air velocity (≤0.08 m s −1 difference, p > 0.05). This highlights the importance of strategically placing AMS units, even in retrofitted barns, to prevent blocking airflow. Although supply fans improved airflow at 1.5 m, they provided no benefit at 0.5 m, where air velocity remained low (0.98 ± 0.1 m s −1 ), comparable to or even lower than other treatments, further suggesting their limited effectiveness, particularly at cow resting height.

  PublisherDOI

• Enhancing Anaerobic Digestion of Agricultural By-Products: Insights and Future Directions in Microaeration

  Bioengineering · 2025-10-18

  reviewOpen accessSenior authorCorresponding

  Anaerobic digestion of manures, crop residues, food waste, and sludge frequently yields biogas with elevated hydrogen sulfide concentrations, which accelerate corrosion and reduce biogas quality. Microaeration, defined as the controlled addition of oxygen at 1 to 5% of the biogas production rate, has been investigated as a low-cost desulfurization strategy. This review synthesizes studies from 2015 to 2025 spanning laboratory, pilot, and full-scale anaerobic digester systems. Continuous sludge digesters supplied with ambient air at 0.28–14 m3 h−1 routinely achieved 90 to 99% H2S removal, while a full-scale dairy manure system reported a 68% reduction at 20 m3 air d−1. Pure oxygen dosing at 0.2–0.25 m3 O2 (standard conditions) per m3 reactor volume resulted in greater than 99% removal. Reported methane yield improvements ranged from 5 to 20%, depending on substrate characteristics, operating temperature, and aeration control. Excessive oxygen, however, reduced methane yields in some cases by inhibiting methanogens or diverting carbon to CO2. Documented benefits of microaeration include accelerated hydrolysis of lignocellulosic substrates, mitigation of sulfide inhibition, and stimulation of sulfur-oxidizing bacteria that convert sulfide to elemental sulfur or sulfate. Optimal redox conditions were generally maintained between −300 and −150 mV, though monitoring was limited by low-resolution oxygen sensors. Recent extensions of the Anaerobic Digestion Model No. 1 (ADM1), a mathematical framework developed by the International Water Association, incorporate oxygen transfer and sulfur pathways, enhancing its ability to predict gas quality and process stability under microaeration. Economic analyses estimate microaeration costs at 0.0015–0.0045 USD m−3 biogas, substantially lower than chemical scrubbing. Future research should focus on refining oxygen transfer models, quantifying microbial shifts under long-term operation, assessing effects on digestate quality and nitrogen emissions, and developing adaptive control strategies that enable reliable application across diverse substrates and reactor configurations.

  PublisherDOI

• Alkaline Hydrolysis of Poultry Carcasses  and Health Risk Assessment of Exposure  to Target Volatile Organic Compounds

  Journal of the ASABE · 2024-01-01 · 3 citations

  article

  Highlights Hydroxide solutions (1 M, 2 M, 4 M) were used for chicken carcass hydrolysis. pH of hydrolysates remained above 13.1 for the entire 10 weeks. Headspace samples had characteristic fish odor due to trimethylamine. Over 17% of the workers exposed to gases for 3 hours daily risk developing serious health risks. Abstract. Animal carcass management is an essential part of a livestock production system. Alkaline hydrolysis is a relatively new disposal method used to digest and break down animal tissues. Despite the effectiveness of inactivating pathogens, alkaline hydrolysis has not been widely accepted as a disposal method because of its high capital and operating costs when done at high temperatures and pressure. The objectives of this research were (1) to test if alkaline solutions at ambient temperature and pressure can be used to hydrolyze poultry carcasses; (2) to quantify target VOCs emitted from carcasses, and (3) to neutralize and aerobically treat hydrolysates to prepare liquid fertilizer. 1 molar (M), 2 M, and 4 M potassium hydroxide solutions were used to hydrolyze chicken carcasses, and the headspace was sampled to quantify target VOCs. The pH of the hydrolysates stayed above 13.1 during the study, which was considered sufficient for eliminating pathogens of concern. Concentrations of target VOCs fluctuated over 10 weeks, and concentrations of trimethylamine (TMA), acetic acid, and propionic acid exceeded their recommended inhalation exposure limits. It was found that more than 17% of the workers exposed to the process headspace gases for 3 h a day would be at a high risk of developing serious chronic health problems. Although the results of this study indicated that chicken carcasses can be hydrolyzed under ambient conditions, they raised concerns about the health risks associated with inhalation exposure to the gases produced during the process. Future studies are needed to adjust daily exposure times depending on the ventilation rates of full-scale alkaline hydrolysis sites. Keywords: Alkaline hydrolysis, Cancer risk, Carcass, Livestock, Solid-phase microextraction.

  PublisherDOI

• Field Measurements of Spatial Air Emissions from Dairy Pastures Using an Unmanned Aircraft System

  Remote Sensing · 2024-08-16 · 2 citations

  articleOpen accessSenior authorCorresponding

  Unmanned aircraft systems (UASs) are emerging as useful tools in environmental studies due to their mobility and ability to cover large areas. In this study, we used an air analyzer attached to a UAS to measure gas and particulate matter (PM) emissions from rotationally grazed dairy pastures in northern Wisconsin. UAS-based sampling enabled wireless data transmission using the LoRa protocol to a ground station, synchronizing with a cloud server. During the measurements, latitude, longitude, and altitude were recorded using a high-precision global positioning system (GPS). Over 1200 measurements per parameter were made during each site visit. The spatial distribution of the emission rates was estimated using the Lagrangian mass balance approach and Kriging interpolation. A horizontal sampling probe effectively minimized the impact of propeller downwash on the measurements. The average concentrations of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) were 800.1 ± 39.7 mg m−3, 1.38 ± 0.063 mg m−3, and 0.71 ± 0.03 mg m−3, respectively. No significant difference was found between CO2 concentrations measured by the UAS sensor and gas chromatography (p = 0.061). Emission maps highlighted variability across the pasture, with an average CO2 emission rate of 1.52 ± 0.80 g day−1 m−2, which was within the range reported in the literature. Future studies could explore the impact of pasture management on air emissions.

  PublisherDOI

• Energy-saving cooling strategies in tunnel-ventilated dairy buildings: Computational fluid dynamics (CFD) simulations and validation

  Smart Agricultural Technology · 2024-09-19 · 7 citations

  articleOpen accessSenior authorCorresponding

  • Energy-efficient cooling strategies were investigated for a dairy barn. • A total of 252 detailed cow models were placed inside a tunnel-ventilated building. • Floor and tube cooling were simulated using ground-source heat pumps as a reference. • CFD simulations demonstrated significantly lower temperatures with tube cooling. • Additionally, tube cooling resulted in 47.5–62.5 % less electricity consumption. Ventilation is a key strategy for addressing heat stress in dairy cattle. In this study, we developed computational fluid dynamics (CFD) models for a 252-head free stall tunnel-ventilated dairy building equipped with ridge openings and circulation fans. A detailed cow model was developed for a standard 625 kg Holstein cattle. Both tube and floor cooling were developed as supplemental cooling strategies using a ground source heat pump while the ventilation fans continued to operate at a reduced air speed (30 to 65 % reduction). The average air velocity within the stalls for the control (1.4 ± 0.32 m s -1 ) was significantly higher than the average velocity achieved with floor cooling (1.02±0.41 m s -1 ) and tube cooling (0.69±0.21 m s -1 ) ( p = 0.043). Despite lower air velocities, CFD simulations showed that the average temperature at cow resting height for tube cooling (27.9 ± 0.21 °C) was significantly lower than that for the control (28.6 ± 0.36 °C) and floor cooling (28.3 ± 0.14 °C) ( p = 0.021). For 252 cows, the total electricity consumption for the control was 40,590 kWh during summer, while for floor cooling, it varied between 30,683 and 36,181 kWh, and for tube cooling, it ranged from 15,879 to 21,378 kWh. Ventilation-related greenhouse gas (GHG) emissions from the tunnel-ventilated barn were 0.12 t of CO 2 eq. per cow. Future studies could investigate the impact of reduced airflow rates on air quality inside the buildings.

  PublisherDOI

• Mitigating heat stress for agricultural workers using computational fluid dynamics (CFD) simulations

  Energy and Buildings · 2024-12-12 · 5 citations

  articleCorresponding
  PublisherDOI

Frequent coauthors

• Brian P. Hetchler

  University of Minnesota

  39 shared

• Jacek A. Koziel

  United States Department of Agriculture

  30 shared

• David B. Parker

  West Texas A&M University

  29 shared

• Sarah Bereznicki

  21 shared

• Larry D. Jacobson

  21 shared

• Albert J. Heber

  21 shared

• Edward A Caraway

  West Texas A&M University

  14 shared

• Larry D. Jacobson

  14 shared