Life Sciences Commons^™

Influence Of Soil And Foliar Application Of Fulvic Acid On Yield Parameters Of Organically Grown Bell Peppers (Capsicum Annuum L.) Under Open-Field Conditions In Tennessee, Pinkky Kanabar, Dilip Nandwani

Student Research

Due to increased demand for healthier fresh produce by consumers, growers are seeking for environmental friendlier techniques to improve sustainability and profitability in organic vegetable production. The use of fulvic acid biostimulant coupled with different mode of application can contribute to enhanced plant growth and high-quality yield. A field experiment was conducted in a randomized complete block design with three replications at the organic farm of Tennessee State University in summer 2021. The influence of foliar and soil application of fulvic acid biostimulant on yield of organically grown bell peppers (Capsicum annuum L.) was investigated. Transplants were raised from organic …

Linking Soil Microbial Community Structure To Potential Carbon Mineralization: A Continental Scale Assessment Of Reduced Tillage, Elizabeth L. Rieke, Shannon B. Cappellazzi, Michael Cope, Daniel Liptzin, Gregory Mac Bean, Kelsey L.H. Greub, Charlotte E. Norris, Paul W. Tracy, Ezra Aberle, Amanda Ashworth, Oscar Bañuelos Tavarez, Andy I. Bary, Roland L. Baumhardt, Alberto Borbón Gracia, Daniel C. Brainard, Jameson R. Brennan, Dolores Briones Reyes, Darren Bruhjell, Cameron N. Carlyle, James J.W. Crawford, Cody F. Creech, Steve W. Culman, Bill Deen, Curtis J. Dell, Justin D. Derner, Thomas F. Ducey, Sjoerd W. Duiker, Miles F. Dyck, Benjamin H. Ellert, Avelino Espinosa Solorio, Steven J. Fonte, Simon Fonteyne, Ann-Marie Fortuna, Jamie L. Foster, Lisa M. Fultz, Audrey V. Gamble, Charles M. Geddes, Deirdre Griffin-Lahue, John H. Grove, Stephen K. Hamilton, Xiying Hao, Zachary D. Hayden, Nora Honsdorf, Julie A. Howe, James A. Ippolito, Gregg A. Johnson, Mark A. Kautz, Newell R. Kitchen, Sandeep Kumar, Kirsten S.M. Kurtz, Francis J. Larney, Katie L. Lewis, Matt Liebman, Antonio Lopez Ramirez, Stephen Machado, Bijesh Maharjan, Miguel Angel Martinez Gamiño, William E. May, Mitchel P. Mcclaran, Marshall D. Mcdaniel, Neville Millar, Jeffrey P. Mitchell, Amber D. Moore, Philip A. Moore, Manuel Mora Gutiérrez, Kelly A. Nelson, Emmanuel C. Omondi, Shannon L. Osborne, Leodegario Osorio Alcalá, Philip Owens, Eugenia M. Pena-Yewtukhiw, Hanna J. Poffenbarger, Brenda Ponce Lira, Jennifer R. Reeve, Timothy M. Reinbott, Mark S. Reiter, Edwin L. Ritchey, Kraig L. Roozeboom, Yichao Rui, Amir Sadeghpour, Upendra M. Sainju, Gregg R. Sanford, William F. Schillinger, Robert R. Schindelbeck, Meagan E. Schipanski, Alan J. Schlegel, Kate M. Scow, Lucretia A. Sherrod, Amy L. Shober, Sudeep S. Sidhu, Ernesto Solís Moya, Mervin St Luce, Jeffrey S. Strock, Andrew E. Suyker, Virginia R. Sykes, Haiying Tao, Alberto Trujillo Campos, Laura L. Van Eerd, Nele Verhulst, Tony J. Vyn, Yutao Wang, Dexter B. Watts, Bryan B. William, David L. Wright, Tiequan Zhang, Cristine L.S. Morgan, C. Wayne Honeycutt

Agricultural and Environmental Sciences Faculty Research

Potential carbon mineralization (Cmin) is a commonly used indicator of soil health, with greater Cmin values interpreted as healthier soil. While Cmin values are typically greater in agricultural soils managed with minimal physical disturbance, the mechanisms driving the increases remain poorly understood. This study assessed bacterial and archaeal community structure and potential microbial drivers of Cmin in soils maintained under various degrees of physical disturbance. Potential carbon mineralization, 16S rRNA sequences, and soil characterization data were collected as part of the North American Project to Evaluate Soil Health Measurements (NAPESHM). Results showed that type of cropping system, intensity of physical …

Carbon-Sensitive Pedotransfer Functions For Plant Available Water, Dianna K. Bagnall, Cristine L. S. Morgan, Michael Cope, Gregory M. Bean, Shannon Cappellazzi, Kelsey Greub, Daniel Liptzin, Charlotte L. Norris, Elizabeth Rieke, Paul Tracy, Ezra Aberle, Amanda Ashworth, Oscar Bañuelos Tavarez, Andy Bary, Roland Louis Baumhardt, Alberto Borbón Gracia, Daniel Brainard, Jameson Brennan, Dolores Briones Reyes, Darren Bruhjell, Cameron Carlyle, James Crawford, Cody Creech, Steven Culman, William Deen, Curtis Dell, Justin Derner, Thomas Ducey, Sjoerd Willem Duiker, Miles Dyck, Benjamin Ellert, Martin Entz, Avelino Espinosa Solorio, Steven J. Fonte, Simon Fonteyne, Ann-Marie Fortuna, Jamie Foster, Lisa Fultz, Audrey V. Gamble, Charles Geddes, Deirdre Griffin-Lahue, John Grove, Stephen K. Hamilton, Xiying Hao, ‪Zachary D. Hayden, Julie Howe, James Ippolito, Gregg Johnson, Mark Kautz, Newell Kitchen, Sandeep Kumar, Kirsten Kurtz, Francis Larney, Katie Lewis, Matt Liebman, Antonio Lopez Ramirez, Stephen Machado, Bijesh Maharjan, Miguel Angel Martinez Gamiño, William May, Mitchel Mcclaran, Marshall Mcdaniel, Neville Millar, Jeffrey P. Mitchell, Philip A. Moore, Amber Moore, Manuel Mora Gutiérrez, Kelly A. Nelson, Emmanuel Omondi, Shannon Osborne, Leodegario Osorio Alcalá, Philip Owens, Eugenia M. Pena-Yewtukhiw, Hanna Poffenbarger, Brenda Ponce Lira, Jennifer Reeve, Timothy Reinbott, Mark Reiter, Edwin Ritchey, Kraig L. Roozeboom, Ichao Rui, Amir Sadeghpour, Upendra M. Sainju, Gregg Sanford, William Schillinger, Robert R. Schindelbeck, Meagan Schipanski, Alan Schlegel, Kate Scow, Lucretia Sherrod, Sudeep Sidhu, Ernesto Solís Moya, Mervin St. Luce, Jeffrey Strock, Andrew Suyker, Virginia Sykes, Haiying Tao, Alberto Trujillo, Laura L. Van Eerd, Nele Verhulst, Tony John Vyn, Yutao Wang, Dexter Watts, David Wright, Tiequan Zhang, Charles Wayne Honeycutt

Agricultural and Environmental Sciences Faculty Research

Currently accepted pedotransfer functions show negligible effect of management-induced changes to soil organic carbon (SOC) on plant available water holding capacity (θAWHC), while some studies show the ability to substantially increase θAWHC through management. The Soil Health Institute's North America Project to Evaluate Soil Health Measurements measured water content at field capacity using intact soil cores across 124 long-term research sites that contained increases in SOC as a result of management treatments such as reduced tillage and cover cropping. Pedotransfer functions were created for volumetric water content at field capacity (θFC) and permanent wilting point (θPWP). New pedotransfer functions had …

Reducing Tillage Affects Long-Term Yields But Not Grain Quality Of Maize, Soybeans, Oats, And Wheat Produced In Three Contrasting Farming Systems, Kirsten Ann Pearsons, Emmanuel Chiwo Omondi, Brad J. Heins, Gladis Zinati, Andrew Smith, Yichao Rui

Agricultural and Environmental Sciences Faculty Research

Reducing tillage has been widely promoted to reduce soil erosion, maintain soil health, and sustain long-term food production. The effects of reducing tillage on crop nutritional quality in organic and conventional systems, however, has not been widely explored. One possible driver of crop nutritional quality might be the changing soil nitrogen (N) availability associated with reduced tillage in various management systems. To test how reducing tillage affects crop nutritional quality under contrasting conventional and organic farming systems with varied N inputs, we measured nutritional quality (protein, fat, starch, ash, net energy, total digestible nutrients, and concentrations of Ca, K, Mg, …

Stimulation Of Ammonia Oxidizer And Denitrifier Abundances By Nitrogen Loading: Poor Predictability For Increased Soil N2o Emission, Yong Zhang, Feng Zhang, Diego Abalos, Yiqi Luo, Dafeng Hui, Bruce A. Hungate, Pablo García-Palacios, Yakov Kuzyakov, Jørgen Eivind Olesen, Uffe Jørgensen, Ji Chen

Biology Faculty Research

Unprecedented nitrogen (N) inputs into terrestrial ecosystems have profoundly altered soil N cycling. Ammonia oxidizers and denitrifiers are the main producers of nitrous oxide (N₂O), but it remains unclear how ammonia oxidizer and denitrifier abundances will respond to N loading and whether their responses can predict N-induced changes in soil N₂O emission. By synthesizing 101 field studies worldwide, we showed that N loading significantly increased ammonia oxidizer abundance by 107% and denitrifier abundance by 45%. The increases in both ammonia oxidizer and denitrifier abundances were primarily explained by N loading form, and more specifically, organic N …

Soil Bacteria In Urban Community Gardens Have The Potential To Disseminate Antimicrobial Resistance Through Horizontal Gene Transfer, Abdullah Ibn Mafiz, Yingshu He, Wei Zhang, Yifan Zhang

Agricultural and Environmental Sciences Faculty Research

Fifteen soil and 45 vegetable samples from Detroit community gardens were analyzed for potential antimicrobial resistance contamination. Soil bacteria were isolated and tested by antimicrobial susceptibility profiling, horizontal gene transfer, and whole-genome sequencing. High-throughput 16S rRNA sequencing analysis was conducted on collected soil samples to determine the total bacterial composition. Of 226 bacterial isolates recovered, 54 were from soil and 172 from vegetables. A high minimal inhibitory concentration (MIC) was defined as the MIC greater than or equal to the resistance breakpoint of Escherichia coli for Gram-negative bacteria or Staphylococcus aureus for Gram-positive bacteria. The high MIC was observed in …

Assessing The Impact Of Organic Versus Conventional Agricultural Management On Soil Hydraulic Properties In A Long-Term Experiment, Abdelrahman Alfahham, Matthew T. Amato, Emmanuel Omondi, Daniel Giménez, Alain F. Plante

Agricultural and Environmental Sciences Faculty Research

Investigating the effects of various agricultural management systems on soil hydraulic properties in long-term field experiments allows farmers to evaluate their efficacy in mitigating the effects of droughts and floods, which are expected to intensify in the coming decades. This study's main objective was to quantify soil structural and hydraulic properties in plots under organic manure, organic leguminous, and conventional agricultural management and related tillage practices at Rodale Institute's Farming Systems Trial. Soil cores were collected at depths of 0–10, 10–20, and 20–30 cm and analyzed for soil water retention, saturated hydraulic conductivity (Ksat), soil organic C (SOC), bulk density, …

Can Agricultural Management Induced Changes In Soil Organic Carbon Be Detected Using Mid-Infrared Spectroscopy?, Jonathan Sanderman, Kathleen Savage, Shree R.S. Dangal, Gabriel Duran, Charlotte Rivard, Michel A. Cavigelli, Hero T. Gollany, Virginia L. Jin, Mark A. Liebig, Emmanuel Chiwo Omondi, Yichao Rui, Catherine Stewart

Agricultural and Environmental Sciences Faculty Research

A major limitation to building credible soil carbon sequestration programs is the cost of measuring soil carbon change. Diffuse reflectance spectroscopy (DRS) is considered a viable low-cost alternative to traditional laboratory analysis of soil organic carbon (SOC). While numerous studies have shown that DRS can produce accurate and precise estimates of SOC across landscapes, whether DRS can detect subtle management induced changes in SOC at a given site has not been resolved. Here, we leverage archived soil samples from seven long-term research trials in the U.S. to test this question using mid infrared (MIR) spectroscopy coupled with the USDA-NRCS Kellogg …

Multi-Year Incubation Experiments Boost Confidence In Model Projections Of Long-Term Soil Carbon Dynamics, Siyang Jian, Jianwei Li, Gangsheng Wang, Laurel A. Kluber, Christopher W. Schadt, Junyi Liang, Melanie A. Mayes

Agricultural and Environmental Sciences Faculty Research

Global soil organic carbon (SOC) stocks may decline with a warmer climate. However, model projections of changes in SOC due to climate warming depend on microbially-driven processes that are usually parameterized based on laboratory incubations. To assess how lab-scale incubation datasets inform model projections over decades, we optimized five microbially-relevant parameters in the Microbial-ENzyme Decomposition (MEND) model using 16 short-term glucose (6-day), 16 short-term cellulose (30-day) and 16 long-term cellulose (729-day) incubation datasets with soils from forests and grasslands across contrasting soil types. Our analysis identified consistently higher parameter estimates given the short-term versus long-term datasets. Implementing the short-term and …

Relationships Between Vegetation And Soil Seed Banks Along A Center-To-Edge Gradient On A Tropical Coral Island, Yao Huang, Hai Ren, Jun Wang, Nan Liu, Shuguang Jian, Hongyue Cai, Dafeng Hui, Qinfeng Guo

Biology Faculty Research

Few studies have focused on the relationships between vegetation and soil seed banks on small islands. To better understand the pattern and regeneration potential of seed banks on tropical coral islands, we measured environmental factors and the species composition, and species richness of soil seed banks and vegetation along a gradient from the center to the edges on East Island in the South China Sea. The results showed that the similarity between the species composition of vegetation and seed banks increased from the center to the edge. In the center, species richness in both vegetation and seed banks was positively …

Effects Of Nitrogen Fertilization And Bioenergy Crop Type On Topsoil Organic Carbon And Total Nitrogen Contents In Middle Tennessee Usa, Jianwei Li, Siyang Jian, Chad S. Lane, Yuehan Lu, Xiaorui He, Gangsheng Wang, Melanie A. Mayes, Kudjo E. Dzantor, Dafeng Hui

Agricultural and Environmental Sciences Faculty Research

Nitrogen (N) fertilization affects bioenergy crop growth and productivity and consequently carbon (C) and N contents in soil, it however remains unclear whether N fertilization and crop type individually or interactively influence soil organic carbon (SOC) and total N (TN). In a three-year long fertilization experiment in switchgrass (SG: Panicum virgatum L.) and gamagrass (GG: Tripsacum dactyloides L.) croplands in Middle Tennessee USA, soil samples (0–15cm) were collected in plots with no N input (NN), low N input (LN: 84 kg N ha-1 yr-1 in urea) and high N input (HN: 168 kg N ha-1 yr-1 in urea). Besides SOC …

Nitrogen Fertilization Restructured Spatial Patterns Of Soil Organic Carbon And Total Nitrogen In Switchgrass And Gamagrass Croplands In Tennessee Usa, Jianwei Li, Siyang Jian, Chad S. Lane, Chunlan Guo, Yuehan Lu, Qi Deng, Melanie A. Mayes, Kudjo E. Dzantor, Dafeng Hui

Agricultural and Environmental Sciences Faculty Research

Nitrogen (N) fertilizers can potentially alter spatial distribution of soil organic carbon (SOC) and total nitrogen (TN) concentrations in croplands such as switchgrass (SG: Panicum virgatum L.) and gamagrass (GG: Tripsacum dactyloides L.), but it remains unclear whether these effects are the same between crops and under different rates of fertilization. 13C and 15N are two important proxy measures of soil biogeochemistry, but they were rarely examined as to their spatial distributions in soil. Based on a three-year long fertilization experiment in Middle Tennessee, USA, the top mineral horizon soils (0–15 cm) were collected using a spatially explicit design within …

Responses Of Soil Carbon Sequestration To Climate-Smart Agriculture Practices: A Meta-Analysis, Xiongxiong Bai, Yawen Huang, Wei Ren, Mark Coyne, Pierre-Andre Jacinthe, Bo Tao, Dafeng Hui, Jian Yang, Chris Matocha

Biology Faculty Research

Climate-smart agriculture (CSA) management practices (e.g., conservation tillage, cover crops, and biochar applications) have been widely adopted to enhance soil organic carbon (SOC) sequestration and to reduce greenhouse gas emissions while ensuring crop productivity. However, current measurements regarding the influences of CSA management practices on SOC sequestration diverge widely, making it difficult to derive conclusions about individual and combined CSA management effects and bringing large uncertainties in quantifying the potential of the agricultural sector to mitigate climate change. We conducted a meta-analysis of 3,049 paired measurements from 417 peer-reviewed articles to examine the effects of three common CSA management practices …

Warming Deferentially Altered Multidimensional Soil Legacy Induced By Past Land Use History, Weiling Dong, Alin Song, Xueduan Liu, Bing Yu, Boren Wang, Yuqiu Lu, Yanling Li, Huaqun Yin, Jianwei Li, Fenliang Fan

Agricultural and Environmental Sciences Faculty Research

The legacy effects of previous land use and climate history may affect current soil function. However, the manner in which these legacy effects of land use are modulated by the subsequent climate remains unclear. For this reason, we investigated how the legacies of soil multiple functions left by conversion of grassland to agricultural management were mediated by climate warming with a reciprocal transplant approach. The overall legacy was further separated into the contributions by changes in the abiotic properties of the soil (abiotic process) and microbial community (biotic process). We here hypothesized that warming may mediate the legacy effects of …

Soil Microbial Community Composition And Respiration Along An Experimental Precipitation Gradient In A Semiarid Steppe, Cancan Zhao, Yuan Miao, Chengde Yu, Lili Zhu, Feng Wang, Lin Jiang, Dafeng Hui, Shiqiang Wan

Biology Faculty Research

As a primary limiting factor in arid and semiarid regions, precipitation strongly influences soil microbial properties. However, the patterns and mechanisms of soil microbial responses to precipitation have not been well documented. In this study, changes in soil microorganisms along an experimental precipitation gradient with seven levels of precipitation manipulation (i.e., ambient precipitation as a control and ±20%, ±40% and ±60% of ambient precipitation) were explored in a semiarid temperate steppe in northern China. Soil microbial biomass carbon and respiration as well as the ratio of fungal to bacterial biomass varied along the experimental precipitation gradient and peaked under the …

Convergence Of Microbial Assimilations Of Soil Carbon, Nitrogen, Phosphorus And Sulfur In Terrestrial Ecosystems, Xiaofeng Xu, Dafeng Hui, Anthony W. King, Xia Song, Peter E. Thornton, Lihua Zhang

Biology Faculty Research

How soil microbes assimilate carbon-C, nitrogen-N, phosphorus-P and sulfur-S is fundamental for understanding nutrient cycling in terrestrial ecosystems. We compiled a global database of C, N, P and S concentrations in soils and microbes and developed relationships between them by using a power function model. The C:N:P:S was estimated to be 287:17:1:0.8 for soils and 42:6:1:0.4 for microbes. We found a convergence of the relationships between elements in soils and in soil microbial biomass across C, N, P and S. The element concentrations in soil microbial biomass follow a homeostatic regulation curve with soil element concentrations across C, N, P …

Soil Carbon And Nitrogen Mineralization And Crop Parameters In Typical Maize-Bean Intercropping In Western Kenya, Judith A. Odhiambo, Urszula Norton, Emmanuel C. Omondi, Dennis Ashilenje, Jay B. Norton

Agricultural and Environmental Sciences Faculty Research

Smallholder farmers in western Kenya who plant maize (Zea mays L.) intercropped with beans (Phaseolus vulgaris L.) face many challenges associated with nutrient-poor soils and weather-related crop failures. In regions where temperatures are favorable, crops are grown twice per year during long and short rainy seasons and in other regions, once per year during one long growing season. Growing crops two times per year necessitates frequent land preparation using inversion-type tillage. Little is known about the impact of current tillage-intensive crop management on annual soil organic matter (SOM) recovery. The aim of this study was to assess changes to soil …

Responses Of Soil Respiration And Its Temperature/Moisture Sensitivity To Precipitation In Three Subtropical Forests In Southern China, H. Jiang, Qi Deng, Guoyi Zhou, Dafeng Hui, Deqiang Zhang, S. Liu, Guowei Chu, J. Li

Biology Faculty Research

Both long-term observation data and model simulations suggest an increasing chance of serious drought in the dry season and extreme flood in the wet season in southern China, yet little is known about how changes in precipitation pattern will affect soil respiration in the region. We conducted a field experiment to study the responses of soil respiration to precipitation manipulations – precipitation exclusion to mimic drought, double precipitation to simulate flood, and ambient precipitation as control (abbr. EP, DP and AP, respectively) – in three subtropical forests in southern China. The three forest sites include Masson pine forest (PF), coniferous …

Effects Of Precipitation Increase On Soil Respiration: A Three-Year Field Experiment In Subtropical Forests In China, Qi Deng, Dafeng Hui, Deqiang Zhang, Guoyi Zhou, Juxiu Liu, Shizhong Liu, Guowei Chu, Jiong Li

Biology Faculty Research

Background

The aim of this study was to determine response patterns and mechanisms of soil respiration to precipitation increases in subtropical regions.

Methodology/Principal Findings

Field plots in three typical forests [i.e. pine forest (PF), broadleaf forest (BF), and pine and broadleaf mixed forest (MF)] in subtropical China were exposed under either Double Precipitation (DP) treatment or Ambient Precipitation (AP). Soil respiration, soil temperature, soil moisture, soil microbial biomass and fine root biomass were measured over three years. We tested whether precipitation treatments influenced the relationship of soil respiration rate (R) with soil temperature (T) and soil …