About

Majdi Abou Najm is an Associate Professor of Soil Biophysics in the Department of Land, Air and Water Resources at the University of California, Davis. His academic position is based in the Plant and Environmental Sciences Building. His work focuses on soil biophysics, which involves studying the physical properties and processes of soils, particularly in relation to water management, irrigation, and soil health. He contributes to the department's efforts in understanding soil-water-plant interactions and developing sustainable agricultural practices. His research and expertise support the department's broader goals of advancing knowledge in land, air, and water resources, with an emphasis on practical applications in agriculture and environmental management.

Research topics

• Computer Science
• Economics
• Environmental economics
• Environmental resource management
• Distributed computing

Selected publications

• Global Potential of Agrivoltaics for Sustainable Food and Energy Transitions

  2026-03-13

  articleOpen accessSenior authorCorresponding

  The dual challenge of meeting rising global food demand while accelerating the clean energy transition requires innovative land-use strategies. Agrivoltaics—the co-location of solar photovoltaics and agriculture—offers a transformative solution, yet global adoption has been hindered by a lack of standardized sunlight requirements for crops. Here, we introduce a framework to quantify crop-specific light requirements using the Daily Light Integral (DLI). We define two distinct thresholds: a “theoretical” DLI and a “real-world” DLI. Applying these thresholds to the world’s four staple crops (wheat, maize, rice, and soybean), we assess the global potential for co-generation without compromising food security. Our analysis reveals that even under conservative design scenarios SC40 that prioritize food security, agrivoltaic systems could generate over 100,000 TWh of electricity annually. Soybean and wheat demonstrate the highest compatibility, particularly in the Middle East, South Asia, and the Americas. These findings outline a quantitative pathway for sustainable land-use transitions, showing that multifunctional landscapes can simultaneously mitigate climate change, reduce water use, and strengthen rural resilience. Agrivoltaics exemplifies the water–energy–food–environment nexus at scale by improving land-use efficiency, creating favorable microclimates, and reducing evaporative demand.

  PublisherDOI

• Optimizing the water energy food nexus in Lebanon: a case study of the nexus in a developing country context

  Environmental Development · 2026-01-22 · 2 citations

  article
  PublisherDOI

• Author Correction: Arctic food and energy security at the crossroads

  Communications Earth & Environment · 2025-03-11

  articleOpen access

  Correction to: Communications Earth & Environmenthttps://doi.org/10.1038/s43247-025-02122-6, published online 18 February 2025 In the version of the article initially published, the definition “blended knowledge (BK)” was missing from the Fig. 1 legend and has now been added to the HTML and PDF versions of the article.

  PublisherOA PDFDOI

• Food, Energy, and Health Implications of Agrivolgtaic Farms

  2025-10-29

  articleOpen access

  The societal benefits of agrivoltaics are well supported, with ample empirical evidence for their suitability for collocated energy generation, crop cultivation, and water savings, even for staple crops. What is lacking is a holistic modeling framework to design and optimize AV systems for specific crop types, micro-environments, and panel configurations. To this end, a multiphysics model that solves momentum, energy, and mass exchanges among interacting components, and determines the implications of AV on photosynthesis, power generation, and worker thermal comfort, is introduced. The model is tested against field data from California, and Minnesota. Its applications are illustrated for a representative AV scenario using weather data from central New Jersey, showcasing the multifaceted benefits of AV for a tomato farm under photovoltaic panels. In this scenario, the model predicts a 5.6 °C reduction in average daytime panel temperature (compared to a regular PV installation), reducing overheating-related energy losses by 15.2%. Despite a 47% reduction in light for the setup modeled here, net carbon assimilation declined only by 31%. Daytime crop leaf temperature declined by 1.84 °C, and these reductions offset some of the decline in carbon assimilation. Another benefit is the reduction in transpiration losses by 22.4% compared to an open crop field. Finally, the average perceived temperature experienced by workers improves by approximately 5.2 °C during working hours. While these are illustrative results for a particular crop and climate, they demonstrate how the model enables integrated assessment and optimization of agrivoltaic benefits across varying climates, crops, and PV technologies.

  PublisherOA PDFDOI

• Renewable energy sources for arctic food sufficiency and sustainability

  npj Sustainable Agriculture · 2025-07-26 · 1 citations

  articleOpen access

  One of the UN’s 17 sustainable development goals (SDGs), SDG 7, is to “ensure access to affordable, reliable, sustainable and modern energy for all.” This goal addresses the need for environmental sustainability while highlighting energy’s vital role in promoting social and economic justice. It calls for sustainable, affordable, modern, and reliable energy usage for the health and well-being of society while mitigating climate change. Here, we briefly review available literature and data to examine how renewable energy, food security, and sustainability are interconnected in Arctic countries and regions, and how these regions can “ensure access to affordable, reliable, sustainable and modern energy for all” and progress towards achieving food self-sufficiency by integrating renewable energy sources into food production systems. We analyze several case studies to draw conclusions on how Arctic communities can become resilient, sustainable, and economically prosperous by promoting local food production while preserving cultural practices.

  PublisherOA PDFDOI

• Emerging issues and research opportunities in vadose zone processes

  Vadose Zone Journal · 2025-07-01 · 6 citations

  articleOpen access

  Abstract The vadose zone—the variably saturated, near‐surface environment that is critical for ecosystem services such as food and water provisioning, climate regulation, and infrastructure support—faces increasing pressures from both anthropogenic and natural factors, including changing climatic conditions. A more comprehensive understanding of vadose zone processes and interactions is imperative to effectively address these challenges and safeguard water and soil resources. This review outlines selected key issues, knowledge gaps, and research opportunities across six thematic sections. Each section presents a problem statement, a summary of recent innovations, and a compilation of emerging challenges and study opportunities. The selected topics include scaling and modeling of vadose zone properties and processes, soil moisture monitoring initiatives, surface energy balance, interplay between preferential water flow paths and biogeochemical processes, interactions between fires and vadose zone dynamics, and emerging contaminants and their fate in the vadose zone. This overview is intended to serve as a compendium of vadose zone science that encompasses both insights gained from prior research and anticipated needs for the coming years.

  PublisherDOI

• Effects of red and blue light treatment on water, microclimate, soil and tomato crops in California

  Energy Nexus · 2025-12-11

  articleOpen access1st authorCorresponding

  • Use of spectral-selective light filters above crops improves water use efficiency. • Despite yield reduction under filters, water use efficiency increased under filters. • Feasibility analysis show overall land productivity increased despite yield reduction. • Those encouraging results position agrivoltaics as climate-smart solution for agriculture. Recent advances in agrivoltaic systems (AVSs) have revived interest in understanding the effects of not only light intensity but also different light spectra on plants and overall land productivity, with research showing plant carbon assimilation being more efficient under red light, while the more energetic blue light would be more effective for producing solar electricity. AVSs are highly efficient in harvesting solar radiation for the co-generation of food and solar electricity, thus resulting in higher land productivity, compared to single-use alternatives, i.e., agriculture or utility-scale solar. This is particularly advantageous in arid and semi-arid areas with abundant sun and limited land and water. The question becomes: how much light and what particular spectra of light are more efficient for food and for energy conversion, and how can any light treatment impact water, soil, microclimate and plant productivity? This study explores the potentials of spectrally selective PV panels by testing the performance of field grown processing tomato with the focus on red and blue light treatments. The study evaluates crop productivity and water savings by monitoring microclimate, soil, and plant responses under two specific wavelength patterns (red and blue filters) compared to the full unfiltered light spectrum (control). The red and blue treatments, applied on processing tomatoes in Yolo County (California), yielded 67 % and 58 % of the control, respectively. However, changes in the microclimate — particularly the reduction in solar radiation —resulted in a significant decrease in evapotranspiration. Consequently, the potential water use efficiency (WUE) for the blue and red light treatments compared to the control was improved by 10 % and 13 %, respectively. Overall, our study suggests that benefits from renewable energy and reduced water usage could offset yield reductions, making spectrally selective AVSs a potentially viable and sustainable land-use option, especially in water-scarce regions.

  PublisherDOI

• Investigation of the prevalence of Enterobius vermicularis infection in Kindergartens in Lahijan City, in 2023-2024

  Journal of Torbat Heydariyeh University of Medical Sciences · 2025-06-01

  articleOpen access1st authorCorresponding
  PublisherOA PDFDOI

• Modeling nitrate leaching risk from flood managed aquifer recharge in California's agricultural lands

  Vadose Zone Journal · 2025-11-01

  articleOpen access

  Abstract Flood managed aquifer recharge (Flood‐MAR) is an emerging practice to enhance groundwater sustainability through recharge of aquifers. However, in agricultural systems Flood‐MAR may harm groundwater quality, given residual soil nitrate (NO 3 − ). This research evaluated Flood‐MAR NO 3 − leaching risk across a precipitation and soil textural gradient in a globally important agricultural region, California's Central Valley, and whether Flood‐MAR timing strategies could mitigate the risk. Using multi‐decadal root zone water quality model simulations of irrigated and fertilized maize (250 kg N ha −1 year −1 ) on well‐drained soils as a representative case‐study, results suggest Flood‐MAR can be used with near‐negligible additional NO 3 − leaching in locations with median annual precipitation >400 mm year −1 . In those locations, wet‐year precipitation leached most residual NO 3 − without practicing Flood‐MAR. At drier locations, Flood‐MAR NO 3 − leaching risk increased most clearly in loamy soils. Additional NO 3 − leaching risk increased in drier climates because minimal precipitation‐driven deep percolation maintained residual NO 3 − accumulation across growing seasons. In fine‐texture soils, NO 3 − leaching risk was mitigated by denitrification, preventing residual NO 3 − accumulation. Flood‐MAR practices diminished denitrification, leaching NO 3 − rapidly when soils were colder and biogeochemically inactive, and thereby decreased growing season denitrification when soils were warmer and denitrification rates higher. Effects of Flood‐MAR timing strategies (January Flood‐MAR vs. March Flood‐MAR), combined with variable pauses among applications (3‐ vs. 7‐ vs. 21‐day intervals) were negligible. Infrequent Flood‐MAR should be practiced with care in arid climates and especially after prolonged droughts coinciding with more limited irrigation water supplies that constrain salt‐leaching practices all favoring residual NO 3 − accumulation.

  PublisherOA PDFDOI

• Arctic food and energy security at the crossroads

  Communications Earth & Environment · 2025-02-18 · 2 citations

  articleOpen access

  Arctic food systems blend Traditional Ecological Knowledge with modern, often energy-intensive influences, triggered by colonization. Food systems’ future depends on alignment of tradition with innovation, facilitation of resilience and a heritage-driven interaction with the global economy – at a pace determined by local communities. Arctic food systems blend Traditional Ecological Knowledge with modern, often energy-intensive influences, triggered by colonization. Food systems’ future depends on alignment of tradition with innovation – at a pace determined by local communities.

  PublisherOA PDFDOI

Frequent coauthors

• Laurent Lassabatère

  École Nationale des Travaux Publics de l'État

  75 shared

• Ryan D. Stewart

  62 shared

• Simone Di Prima

  University of Basilicata

  59 shared

• Rafaël Angulo-Jaramillo

  Université Claude Bernard Lyon 1

  53 shared

• M. El‐Fadel

  Khalifa University of Science and Technology

  43 shared

• David E. Rupp

  35 shared

• Ibrahim Alameddine

  American University of Beirut

  31 shared

• Rabi H. Mohtar

  Texas A&M University

  30 shared