About

Patrick H. Brown is a Distinguished Professor in the Department of Plant Sciences at UC Davis. He holds a Ph.D. from Cornell University, where his research focused on the essentiality of nickel for higher plants, and a B.Ag.Sci with first class honors from The University of Adelaide, Australia, in Agricultural Sciences and Biochemistry. His current teaching includes courses such as Introduction to International Agricultural Development, Just Coffee, Mineral Nutrition of Plants, and Environmental Interactions of Cultivated Plants. Brown's external activities contribute significantly to his scholarship, including roles as Associate Editor for Frontiers in Plant Science, Science Advisor for multiple organizations such as Plant Impact LLC, Compass Minerals, and NewAg International, and positions on various boards including the East San Joaquin Water Coalition and the International Council for Plant Nutrition. He has been recognized with several awards, including the Experiment Station Section Excellence in Multistate Research Award from USDA, and multiple Researcher of the Year honors from industry foundations. His research interests encompass plant nutrition, foliar fertilizers, plant physiology, and precision horticulture, with a focus on plant nutrients, water management, and sustainable crop production.

Research topics

• Computer Science
• Biology
• Ecology
• Agronomy
• Biotechnology
• Environmental science
• Inorganic chemistry
• Chemistry
• Biochemistry
• Agroforestry

Selected publications

• Integrating almond crop residues for whole orchard regenerative management

  SSRN Electronic Journal · 2026-01-01

  preprintOpen access
  PublisherDOI

• Utilizing Pharmacy as a Bridge to Connect Health Care and Public Health

  North Carolina Medical Journal · 2025-07-30

  articleOpen access1st authorCorresponding

  Pharmacy and public health may not be thought of as natural partners, but the opportunity for collaboration is strong. Each system is available, accessible, and trusted by the public. By identifying shared health priorities, pharmacy and public health can come together to strengthen each other and improve health for all.

  PublisherOA PDFDOI

• Biostimulants in Agriculture: Editorial

  Physiologia Plantarum · 2025-01-01 · 17 citations

  editorialOpen accessSenior author

  Biostimulants are becoming an important tool in agriculture, helping to improve crop growth, resilience, and quality while supporting sustainable farming practices. These products, made from natural substances or microorganisms, enhance plants' natural processes. They can improve how plants use nutrients, handle stressful conditions like drought or salinity, and boost overall crop productivity and quality. The European Regulation (EU) 2019/1009 defines biostimulants as products “the function of which is to stimulate plant nutrition processes independently of the product's nutrient content with the sole aim of improving one or more of the following characteristics of the plant or the plant rhizosphere: (a) nutrient use efficiency; (b) tolerance to abiotic stress; (c) quality traits; or (d) availability of confined nutrients in the soil or rhizosphere”. This regulation has helped clarify what biostimulants are while encouraging their disciplined use in agriculture (EU 2019). Although biostimulants have shown great potential, there is still much to learn about how they work and how to maximise their benefits. Their effectiveness depends on crop type, dose, and timing, with a particular focus on crop responses under suboptimal conditions. Biostimulants have great potential to address cropping challenges such as climate change, resource scarcity, and the need for more sustainable farming methods. They offer a practical approach to increasing food production despite abiotic constraints. This Special Issue of Physiologia Plantarum “Biostimulants in Agriculture” includes seventeen studies that explore how biostimulants can help solve some of agriculture's biggest challenges. These studies investigate how biostimulants improve nutrient use efficiency, enhance plant stress tolerance, boost growth and increase quality traits. They also explore new formulations, like nanoparticles, and innovative concepts, such as glycostimulation, which uses various glycomolecules to enhance plant growth. The research investigates the modes of action of biostimulants and their applications in real-world farming. Using advanced techniques, such as molecular studies and field experiments, these studies demonstrate how biostimulants can be tailored to different plant species, such as tomato, lettuce, maize, oilseed rape, cucumber, wheat, Indian mustard, Arabidopsis and grapevine, and growth conditions. Biostimulants are no longer just an experimental idea; they are becoming an essential part of sustainable agriculture. The studies gathered in this issue provide valuable insights into how biostimulants can shape the future of farming, making it more productive, resilient, and eco-friendly. They also show how new findings can be directly transferred to the field, helping farmers use biostimulants effectively to improve the growth and quality of their produce. Improving nutrient use efficiency (NUE) is a pivotal objective in sustainable agriculture, especially as the global demand for environmentally sound food production intensifies. Several studies in this issue highlight innovative approaches to enhancing NUE and promoting biomass accumulation. Monterisi et al. (2024) employed a multi-omics approach to investigate the role of protein hydrolysates (PHs) in nitrogen-limited lettuce plants. Their findings showed that PHs, particularly the low-molecular-weight fractions, act through hormone-like mechanisms to enhance nitrogen utilization, even under suboptimal nitrogen availability. These effects were linked to the upregulation of auxin and cytokinin biosynthesis pathways, the activation of multifaceted antioxidant responses, and enhanced cell wall plasticity, which collectively boosted plant growth and biomass accumulation under low nitrogen conditions. Pathak et al. (2024) demonstrated the synergistic potential of combining microbial and non-microbial biostimulants in wheat. They developed bioinoculants that significantly improved germination, root architecture, and nutrient content by integrating a functionally competent synthetic microbial community with humic acid or seaweed extracts. Their field trials revealed that wheat plants treated with these integrated biostimulants achieved a 40% increase in grain yield and a substantial increase in macro- and micronutrient profiles. This study underscores the importance of blending microbial diversity with biostimulants to combine agricultural productivity and sustainability. Velasco-Clares et al. (2024) investigated the application of a seaweed-derived biostimulant enriched with bioactive anti-stress compounds under optimal growth conditions. Lettuce plants treated with the biostimulant at an optimal dose of 300 mL/hL showed improved biomass production, enhanced photosynthetic activity, and enriched phytohormones, amino acids, and mineral nutrient profiles. The treatment also stimulated nitrogen assimilation, antioxidant capacity, and concentrations of key antioxidant compounds, contributing to higher crop quality and potential stress resilience. However, the study highlighted the risk of phytotoxic effects at higher doses, such as 500 mL/hL, emphasizing the critical importance of proper dosage for maximizing the benefits of biostimulants. Biostimulants may promote plant growth and development by influencing key physiological and molecular pathways. In Arabidopsis thaliana, Bahmani and Prithiviraj (2024) demonstrated that extracts from Ascophyllum nodosum regulate flowering time through the “MIR156-mediated age pathway”, a central mechanism in developmental transitions. These extracts modulate the balance between key flowering regulators by repressing MIR156, a negative regulator, and enhancing SPLs and MIR172, which promote flowering while downregulating floral repressors like AP2-like genes. Using fucoidan, a compound derived from the seaweed extract, they further highlighted the ability of extract compounds to mimic sugar signalling and activate the flowering pathway. Similarly, Ancín et al. (2024) explored the effects of microalgal and PH extracts on oilseed rape (Brassica napus) and observed significant enhancements in phenological transitions and yield. These improvements were linked to better photosynthetic performance and accelerated developmental processes supported by changes in proteomic and metabolomic profiles. The biostimulants also upregulated antioxidant enzymes, helping plants manage the stress due to rapid phenological changes. Mutlu-Durak et al. (2024) demonstrated that extracts from the brown seaweed Cystoseira barbata significantly enhanced root and shoot growth in wheat (Triticum durum) seedlings. Among the various extraction methods tested, water-based extracts applied to the substrate proved to be the most effective. These treatments increased biomass accumulation and positively affected root morphology and nutrient uptake, highlighting the critical role of biostimulants in optimizing early-stage plant growth. The authors point out that additional studies are required to explore the effects of soil and foliar applications of these extracts on growth, yield, and stress tolerance. Furthermore, the potential of these extracts in soilless systems, as well as the efficacy of ‘greener’ C. barbata extracts like supercritical and cold-pressed variants, must be assessed. In a study on a table grapevine variety, Peli et al. (2025) reported that the soil application of maize gluten-derived protein hydrolysate (GDPH) led to a shift in berry development dynamics, improving quality characteristics such as increased anthocyanin and sugar levels, larger berry diameter, and preserved berry firmness. Interestingly, the transcriptomic analysis revealed that GDPH influenced the expression of genes involved in accelerating ripening-specific metabolic processes, including the repression of green/immature berry development and cell-wall softening pathways while promoting genes involved in anthocyanin synthesis. Abiotic stresses such as drought, salinity, extreme temperatures, and heavy metal toxicity are critical challenges in agriculture, substantially reducing crop productivity and posing a threat to global food security. Biostimulants are emerging as innovative solutions to alleviate these effects by enhancing plant resilience through various biochemical and physiological mechanisms. Cerruti et al. (2024) investigated the effects of an algae-based (A. nodosum and Laminaria digitata) biostimulant on tomato plants subjected to mild drought stress, revealing its ability to prime plants by modulating early stress markers and regulating reactive oxygen species (ROS) levels through enzymatic and non-enzymatic scavengers. This priming induced endogenous defence mechanisms before plants were exposed to stress, thus preventing oxidative damage and protecting plant physiological functions. Transcriptomic analysis further highlighted its role in modulating genes linked to water transport, oxidative stress response, and cellular organization. The authors suggest that the selected timings and the adopted RNA-seq data analysis techniques, by either monitoring differentially expressed genes or groups of coregulated genes, can be a valid, future approach to provide further information about biostimulant mode of action. Similarly, Brown et al. (2024) demonstrated that chitosan-fulvic acid nanoparticles (Ch-FANPs) enhance drought tolerance in maize by activating antioxidant enzyme activities, including ascorbate peroxidase (APX) and catalase (CAT), and reducing lipid peroxidation and hydrogen peroxide (H₂O₂) accumulation. This treatment also induced the expression of key drought-responsive transcription factors involved in signaling pathways and water-use efficiency, offering a comprehensive mechanism for improved resilience under water deficit conditions. Salinity stress, which disrupts ionic balance and water uptake, was addressed by Islam et al. (2024) through the application of glycine betaine (GB) in Indian mustard (Brassica juncea). GB improved osmotic regulation and cellular ionic homeostasis, reduced oxidative damage, and increased growth, biomass, and nutrient uptake even under high salt concentrations. Meanwhile, heavy metal toxicity due to cadmium (Cd) was mitigated in grapevine seedlings using smoke solutions (SS) derived from vineyard pruning waste, as reported by Yağcı et al. (2024). The application of 0.5% SS enhanced antioxidant defences by upregulating the activity of enzymes such as superoxide dismutase (SOD), CAT, and APX, reducing malondialdehyde (MDA, marker of lipid peroxidation) levels, and preserving photosynthetic efficiency and membrane integrity. The study showed that transforming organic plant waste into smoke solutions provides an eco-friendly approach to boosting the sustainability of viticulture and adding value to waste materials. However, future studies are needed to investigate the interactions between smoke solutions and heavy metals and their effects on grapevine yield. A study by Daler and Kaya (2024) explored the use of alpha-lipoic acid as a foliar treatment to reduce oxidative damage in two grapevine rootstocks with different levels of drought tolerance: the drought-tolerant ‘1103 P’ and the drought-sensitive ‘3309 C’. Treatments with alpha-lipoic acid significantly improved physiological parameters, such as chlorophyll content, stomatal conductance, and antioxidant enzyme activities (SOD, CAT, APX), while decreasing electrolyte leakage and MDA levels under drought conditions. Particularly, the rootstock ‘1103 P’ demonstrated superior performance at a concentration of 50 μM alpha-lipoic acid, emphasizing the importance of rootstock selection in optimizing responses to drought stress. These findings highlight the potential of alpha-lipoic acid as a natural and eco-friendly biostimulant for improving grapevine resilience in water-limited environments. The arbuscular mycorrhizal fungi Rhizophagus irregularis and biochar (BC) were shown by Wen et al. (2024) to synergistically improve the growth and physiological characteristics of switchgrass under saline-alkali stress. Their combined application significantly increased plant biomass, photosynthetic efficiency, and antioxidant enzyme activity compared to individual treatments. The combined treatment also enhanced light response parameters, stomatal conductance, and the maximum electron transfer rate, offering a promising strategy to mitigate saline-alkali stress and improve crop productivity. A study on Bacillus zanthoxyli HS1 (BzaHS1) by Barghi and Jung (2024) demonstrated its effectiveness in mitigating salt and heat stress in cabbage and cucumber plants. Application of BzaHS1 or its volatile organic compounds (VOC) enhanced seedling growth under stress conditions by reducing oxidative stress through increased enzymatic activities of SOD, CAT and APX. Additionally, BzaHS1 triggered callose accumulation and minimized stomatal opening, further enhancing plant resilience. These findings highlight the potential of BzaHS1 and its VOC in improving systemic plant tolerance to abiotic stresses through modulation of stress-regulatory networks. Low-temperature stress, another significant abiotic challenge, was addressed by Sun et al. (2024), who demonstrated that the combined myo-inositol and corn steep liquor enhanced seedling growth and cold tolerance in cucumber and tomato. This treatment improved photosynthetic pigment levels, reduced MDA and electrolyte leakage, and upregulated cold-responsive genes, such as CBF1 and COR. Notably, the synergistic effects of myo-inositol and corn steep liquor provided significant protection under low-temperature stress, promoting early crop growth and resilience. Jasso-Robles et al. (2024) explored the role of putrescine, a small molecule, as a biostimulant in Arabidopsis. Their research showed that putrescine enhances plant growth and photosynthesis by influencing critical genetic and metabolic pathways. Putrescine application was particularly effective under stress conditions, such as high salinity, where it helps plants maintain their performance. This study highlights putrescine as a promising tool for improving crop tolerance and growth. Finally, in a comprehensive review article, Boulogne et al. (2024) introduced the concept of “glycostimulation”, identifying glycomolecules such as polysaccharides, glycoproteins, and glycolipids as a distinct and versatile category of biostimulants. These compounds may play the dual role of enhancing plant response mechanisms against both abiotic and biotic stresses while simultaneously promoting growth. This unique combination of benefits positions glycomolecules as a promising focus for advancing agricultural productivity and plant health, offering a bridge between stress resilience and improved yield potential. Biostimulants are transforming modern agriculture by providing diverse and innovative strategies to enhance nutrient acquisition, biomass production, stress tolerance, and overall crop performance. The studies assembled in this Special Issue demonstrate how biostimulants regulate plant growth, development, and quality traits of different crop species at various developmental stages, from early vegetative stages to reproductive transitions, showcasing their ability to improve productivity and sustainability. Biostimulants have shown their multifaceted role in addressing key agricultural challenges through molecular modulation, microbial integration, and the application of seaweed-derived products. Advanced formulations and novel mechanisms, such as glycostimulation and nanoparticle-based products, are redefining how we manage crops, offering new perspectives for sustainable farming. These findings underscore the growing importance of biostimulants in real-world agricultural applications, especially in overcoming challenges posed by climate change and resource limitations. By bridging scientific discovery with practical implementation, biostimulants provide valuable tools to create resilient, productive, and environmentally friendly farming systems, making them an important part of the future of agriculture. Collectively, these studies demonstrate the ability of biostimulants to challenge various abiotic stresses through mechanisms that include improved antioxidant activity, ionic balance, osmotic regulation, and transcriptional reprogramming, underscoring their potential as a sustainable tool for enhancing crop resilience in challenging environmental conditions while preserving or promoting growth and quality.

  PublisherOA PDFDOI

• The optimization of crop response to climatic stress through modulation of plant stress response mechanisms. Opportunities for biostimulants and plant hormones to meet climate challenges.

  New Phytologist · 2025-11-10 · 7 citations

  articleOpen accessSenior authorCorresponding

  This review discusses the use of agronomic management practices to enhance crop stress resilience to climate stress through the modulation of natural plant growth regulatory pathways. The use of biostimulants or plant hormones to improve crop resilience is subject to strict regulatory oversight if changes in the regulation of plant growth are implied. Climate change is a major threat to crop potential and is characterized by both long-term shifts in temperature and precipitation patterns as well as increased occurrence of extreme weather events, posing an immediate threat to agriculture. Breeding and exogenous inputs have been used to enhance cropping system resilience, although these management practices are either too slow or constrained by cost and availability, to address rapidly emerging climate challenges. Exogenous biostimulants, microbials and plant hormones have shown great promise as novel mechanisms to optimize natural plant resilience, resulting in immediate but non-permanent improvements in plant responses to climate-induced stresses, representing a powerful but underexplored approach to enhance crop productivity under climate stress. The use of these exogenous inputs is, however, constrained by outdated and scientifically unsound regulations that consider any such modification as pesticidal in nature. The failure to modernize regulatory frameworks for the use of biostimulants in agriculture will constrain the development of safe effective tools and deprive growers of means to respond to climate change. Here, we discuss the scientific rationale for eliminating the regulatory barriers governing biostimulants or products that modulate plant regulatory networks and propose a framework for enabling legislation to strengthen cropping system resilience.

  PublisherOA PDFDOI

• Integrating hyperspectral radiative transfer modeling and Machine learning for enhanced nitrogen sensing in almond leaves

  Computers and Electronics in Agriculture · 2025-03-14 · 8 citations

  articleSenior author
  PublisherDOI

• The optimization of crop response to climatic stress through modulation of plant stress response mechanisms. Opportunities for biostimulants and plant hormones to meet climate challenges

  ArXiv.org · 2025-06-02

  preprintOpen accessSenior author

  Climate change is a major threat to crop potential and is characterized by both long-term shifts in temperature and precipitation patterns as well as increased occurrence of extreme weather events, these extreme weather events are the most immediate and intractable threat to agriculture. Crop resilience in the face of stress depends upon the speed and effectiveness with which plants and cropping systems sense and respond to that stress. A variety of agronomic practices including breeding, exogenous inputs (nutrients, water, biostimulants and others) and shifts in cultivation practice have been used to influence plant stress response to achieve the goal of increased plant and cropping system resilience. Traditional breeding is a powerful tool that has resulted in stable and long-term cultivar improvements but is often too slow and complex to meet the diverse, complex and unpredictable challenges of climate induced stresses. Increased inputs (water, nutrients, pesticides etc.) and management strategies (cropping system choice, soil management etc.) can alleviate stress but are often constrained by cost and availability of inputs. Exogenous biostimulants, microbials and plant hormones have shown great promise as mechanisms to optimize natural plant resilience resulting in immediate but non-permanent improvements in plant responses to climate induced stresses. The failure to modernize regulatory frameworks for the use of biostimulants in agriculture will constrain the development of safe effective tools and deprive growers of means to respond to the vagaries of climate change. Here we discuss the scientific rationale for eliminating the regulatory barriers that constrain the potential for biostimulants or products that modulate plant regulatory networks to address climate change challenges and propose a framework for enabling legislation to strengthen cropping system resilience.

  PublisherOA PDFDOI

• Adequate Boron Supply Modulates Carbohydrate Synthesis and Allocation in Sugarcane

  Plants · 2025-02-21 · 5 citations

  articleOpen access

  Boron (B) is an essential and widely studied element in plants. Due to B dynamics in highly weathered soils, its concentration is generally low. Among other benefits, B interacts with calcium pectate, promotes stability on cellular membrane, and influences directly on plant nutrients uptake and non-structural metabolites synthesis. In sugarcane (Saccharum spp.) crop, adequate B supply has been associated with juice quality and yield of stalks and sugar and its response on adequate B concentration on commercial fields can differ greatly even into a group of varieties recommended for the same production environment. In this context, the authors aimed to assess the effects of B availability on sugarcane root and shoot development, nutrient status, and carbohydrate synthesis and allocation in two sugarcane varieties recommended for the same production environment using hydroponic solution. The experimental design was completely randomized and consisted of four treatments and four replicates. The treatments comprised two sugarcane varieties (RB867515 and RB92579) and two B concentrations (0.05 and 0.5 mg L−1) considered deficient and adequate, respectively, for plant development. Carbohydrate partitioning, nutrient concentrations in various plant parts, and growth and morphological parameters were evaluated. Under adequate B supply, the total concentrations of reducing sugars and sucrose increased 67 and 20% in RB867515 and 30 and 20% in RB92579, respectively, whereas starch decreased by 27% for both varieties. Adequate B supply increased the concentrations of all elements in all plant organs, except for N and K in leaves, and improved most yield and morphological parameters. Principal component analysis correlated the higher carbohydrates concentration and yield parameters with the variety RB92579, whereas the highest concentration of most nutrients was mainly associated with the variety RB867515, especially under adequate B supply. The main influence of adequate B supply was on carbohydrate synthesis. Although the sugarcane varieties responded differently to B availability, their biometric parameters were enhanced by adequate B supply. These results emphasize the need for B fertilization, regardless of the sugarcane variety’s susceptibility to B deficiency.

  PublisherOA PDFDOI

• Unlocking the black box of plant biostimulants

  Scientia Horticulturae · 2025-07-30 · 21 citations

  articleOpen access

  Over the recent years, plant biostimulants have shifted from the margins of agricultural innovation to the forefront of global discussions towards sustainable crop production models. Despite their growing popularity and commercial relevance, key questions persist regarding their actual effects on plants, the validation of their claimed benefits, and the identification of reliable metrics to assess their impact. This editorial aspires to navigate through the definitions, scientific evidence, and regulatory frameworks shaping the current and future landscape of biostimulants. Building on this foundation, the present article reflects on the broader scientific discussion initiated during the ISHS HortForum on plant biostimulants, aiming to distil key conceptual and methodological challenges in the field. An integrated perspective on how biostimulants can be more effectively studied, functionally categorized, and applied in modern agriculture from a range of perspectives is discussed. This analysis provides a critical synthesis of current scientific thinking. It highlights key research priorities, particularly concerning mechanisms of action, quantifiable effects, and the role of biostimulants in promoting resilient, sustainable cropping systems.

  PublisherDOI

• Editorial: Foliar nutrient analysis in crop species: successes, opportunities and challenges

  Frontiers in Plant Science · 2025-12-08

  articleOpen accessSenior author

  We are pleased to introduce the Research Topic "Foliar Nutrient Analysis in Crop Species: Successes, Opportunities and Challenges". The goal of this special issue was to summarize the latest scientific advances in foliar analysis and alternative diagnostic methods to improve nutrient application efficiency, enhance field production, and minimize negative environmental impacts. This collection brings together 9 articles from 71 authors, offering valuable insights into integrated, sustainable, and precision fertilization approaches.The contributing articles address key themes in modern crop nutrition. Several studies focus on integrated and balanced fertilization, the following: Nawaz et al. (2024) demonstrated that supplementing standard NP fertilizer with K and Zn in wheat significantly improved physiological performance, nutrient use efficiency, and grain yield, mainly through enhanced chlorophyll content, improved gas exchange parameters, and greater nutrient uptake efficiency. Mulugeta et al. (2025) found that combining the right carrot variety with an optimal rate of blended NPSB (Nitrogen, Phosphorus, Sulfur, Boron) fertilizer was critical for maximizing vegetative growth and marketable root yield under field conditions in Ethiopia. Garg et al. (2024) showed that enriched organic formulations, prepared from paddy husk ash and potato peel compost, can serve as effective and sustainable alternatives to farmyard manure, significantly enhancing plant growth, yield, and soil fertility indicators within a multicrop system. Amjadi et al. (2025) highlighted that combining complete chemical fertilizer with effective weed control achieved the highest potato tuber yield, while also improving tuber quality traits, such as dry matter and specific gravity, providing practical insights for integrated and sustainable production systems.Another set of articles explores innovative foliar applications and advanced diagnostics, the following ones: Ye et al. (2025) found that foliar application of magnesium sulfate effectively corrected Mg deficiency in high-density sweet corn, and significantly increased fresh ear yield and nutrient uptake, while enhancing carbohydrate accumulation and overall physiological efficiency. Xu et al. (2025) discovered that a low concentration of the fungicide mancozeb not only controlled disease, but also boosted silage maize yield and the relative abundance of beneficial phyllosphere microorganisms, demonstrating that moderate fungicide inputs can modulate the phyllosphere microbiome and improve plant health potential. Gill et al. (2024) successfully used visible-to-shortwave infrared (VSWIR) spectroscopy to develop strong predictive models for a wide range of macronutrients and micronutrients in winter wheat, demonstrating a powerful, non-destructive method for assessing plant nutrient status that could be integrated into high-throughput phenotyping and digital nutrient monitoring.Finally, the collection also examines plant resilience and sustainable forage alternatives, via the following articles: 2024) evaluated twelve native and endemic plant species from the Canary Islands; they found that their nutritional value was comparable to that of traditional forages like alfalfa, emphasizing the potential of native biodiversity to support sustainable livestock feeding systems in arid and insular regions.All these articles provide a comprehensive overview of the current successes and opportunities in crop nutrition. We hope that this collection will serve as an important resource for improving nutrient management, crop productivity, and fruit quality, while also revealing more efficient and sustainable agricultural practices.

  PublisherOA PDFDOI

• Organic soil amendment effects on soil hydrology in an almond orchard evaluated using time-lapse electrical resistivity tomography

  Agricultural Water Management · 2024-07-29 · 3 citations

  articleOpen access

  Adding organic amendments to soils in orchards has been suggested as a climate-smart agricultural practice that can increase resilience to extremes such as drought. The benefits of adding almond hulls and shells to soil include releasing potassium into the soil, improving water infiltration, reducing soil water evaporation, and enhancing water-holding capacity. In this study, soil infiltration and root water uptake (RWU) patterns of almond trees in amended and control soil treatments were investigated. An almond orchard was mulched with a mixture of almond hulls and shells used as surface-applied organic matter amendments. The combined use of time-lapse electrical resistivity tomography (ERT), stem water potential (SWP) and leaf water potential (LWP) measurements were used to evaluate RWU, soil infiltration patterns, and tree water status at different times during the study. The results of the ERT showed that the RWU patterns for the almond trees are distinct between the amended and the control treatments after the irrigation was applied. Compared to the control treatment, the amended treatment allowed the soil to store more water. Regardless of treatment, the majority of RWU patterns were observed in the top 0.5–1 m root zone depth. Almond trees began to recover from stress, as indicated by the SWP and LWP values, four hours after the start of irrigation. In addition, this was demonstrated by the ERT measurements, which revealed the RWU activity four hours after the irrigation had been applied. This research reveals that time-lapse ERT surveys combined with soil and tree water status data can infer patterns of RWU in almond trees grown with organic soil amendments and under controlled conditions. Furthermore, it was concluded that using almond hulls and shells as organic matter amendments can help almond growers improve infiltration, making almond production more resilient to climate change-related extremes such as droughts.

  PublisherDOI

Recent grants

• Quantitative Methods for Macromolecular Interactions

  NIH · $1.0M

Frequent coauthors

• Shengke Tian

  Zhejiang University

  104 shared

• Hening Hu

  Yunnan University

  96 shared

• Xiaoe Yang

  Zhejiang University

  88 shared

• Peter Schuck

  National Institute of Biomedical Imaging and Bioengineering

  78 shared

• Steven A. Weinbaum

  75 shared

• John M. Labavitch

  University of California, Davis

  74 shared

• Zhenli He

  University of Florida

  69 shared

• Lingli Lu

  Zhejiang University

  66 shared

Education

• PhD, Agronomy

  Cornell University

  1988

• BSc Hons. (1st), Agriculture

  University of Adelaide

  1982

Awards & honors

• Experiment Station Section Excellence in Multistate Research…
• Researcher of the Year, Fluid Fertilizer Foundation (2012)
• Researcher of the Year, SOPIB (2011)
• Researcher of the Year, Potash and Phosphate Institute (2009…
• Patrick Brown receives prestigious Dennis R. Hoagland and Le…