Soil Science Commons^™

Turning Waste Into Fertilizer: Aloe Vera Leaf Shavings Improve Plant Growth And Support Soil Fertility In Organic Systems, Isaiah Edward Jaramillo, Carine Cocco, James Jihoon Kang, Chu-Lin Cheng, Engil Pereira

School of Earth, Environmental, & Marine Sciences Faculty Publications

The Aloe vera industry discards large amounts of outer leaf tissue (“shavings”), creating an opportunity to repurpose this byproduct as a sustainable fertilizer. This study evaluated whether aloe shavings can serve as a plant-based alternative to compost in organic Aloe vera production. A field trial in the Lower Rio Grande Valley of Texas tested three treatments: aloe shavings (applied to supply 39 kg N ha−1), organic compost (39 kg N ha−1), and a non-fertilized control. Laboratory incubations further assessed nitrogen mineralization and microbial respiration. Aloe shavings significantly enhanced vegetative growth: leaf number increased from 5.7 to 12.3 leaves per plant …

Tillage Legacy, Grasses And Soil Texture Shape Soil Organic Carbon Recovery In Semi-Arid Woodland, Samantha Colunga, Alejandro Fierro-Cabo, Bradley O. Christoffersen, Engil Pereira

School of Earth, Environmental, & Marine Sciences Faculty Publications

Soil degradation from intensive tillage poses a critical barrier to carbon sequestration, particularly in semi-arid regions where low rainfall limits ecosystem recovery. As climate change expands arid zones globally, understanding the long-term potential for soil organic carbon (SOC) recovery in degraded lands becomes increasingly urgent. Here, we analyze reforested chronosequences (4–36 years post-abandonment) in formerly cultivated subtropical thornscrub woodlands to assess SOC dynamics across gradients of soil texture and degradation. We introduce a novel degradation index (DI), integrating SOC deficit and grass dominance, to evaluate how invasive grasses, commonly overlooked in restoration metrics, impede nitrogen (N2)-fixing tree establishment and, consequently, …

A Rapid Method For Identifying Plant Oxidative Stress And Implications For Riparian Vegetation Management, Mizanur Rahman, Takashi Asaeda, Kiyotaka Fukahori, Md Harun Rashid, Hideo Kawashima, Junichi Akimoto, Refah Tabassoom Anta

School of Earth, Environmental, & Marine Sciences Faculty Publications

Native and invasive plants of the riverain region undergo a range of environmental stresses that result in excess reactive oxygen species (ROS). Hydrogen peroxide (H2O2) is a relatively stable and quickly quantifiable way among different ROS. The herbaceous species including Artemisia princeps, Sicyos angulatus, and Solidago altissima were selected. The H2O2 and photosynthetic pigment of leaves were measured, soil samples were analyzed to quantify macronutrients such as total nitrogen (TN), total phosphorus (TP), and soil moisture, and photosynthetic photon flux density (PPFD) was also recorded at different observed sites of Arakawa Tarouemon, Japan. The H2O2 concentration of S. altissima significantly …

Can Trichoderma Spp. Contribute To The Bioremediation And Biostimulation Of Plants In Soil Contaminated With Herbicides?, Elaine Damiani Conte, Elton José Da Rosa, Gabriel Rieth Silvestrini, Daiane Da Silva Motta, Christiane Fernandes De Oliveira, Carine Cocco, Gabriel Fernandes Pauletti, Taísa Dal Magro, Joséli Schwambach

School of Earth, Environmental, & Marine Sciences Faculty Publications

This work aimed to evaluate the potential of Trichoderma spp. in the bioremediation of herbicides and biostimulation of plants in herbicide-contaminated soils. In the first phase, the experiment followed a completely randomized design in a 4 × 3 × 4 factorial scheme with five replications, four strains of Trichoderma spp., three herbicides, and four herbicide doses. The mycelial growth speed index (MGSI) of Trichoderma spp. was obtained by growing it in a Petri dish with PDA associated with different doses of herbicides and evaluated every 24 h for 10 days. Results indicated the selection ofTrichoderma harzianumT1A to continue …

Carbon Sequestration Through Conservation Tillage In Sandy Soils Of Arid And Semi-Arid Climates: A Meta-Analysis, Samantha Lynn Colunga, Leila Wahab, Alejandro Fierro-Cabo, Engil Isadora Pujol Pereira

School of Earth, Environmental, & Marine Sciences Faculty Publications

Highlights

• Under CST, SOC increased by 12.74 ± 1.46 % in sandy soils with 5 of the 6 practices contributing to this rise.
• SOC increased up to 15 years post-CST conversion, but more research is needed to assess long-term effects.
• SOC increased by 13% in soils with over 56% sand content under CST.
• SOC increased by 15% in the 0-20 cm depth under CST, with no significant increase at greater depths.
• SOC increased under CST when nitrogen was applied at rates up to 100 kg N ha⁻¹.

Abstract

This meta-analysis assessed soil organic carbon (SOC) percent changes in sandy soils, …

Implementing Organic Fertilization Practices To Improve Aloe Vera Growth And Soil Health In The Lower Rio Grande Valley, Isaiah Edward Jaramillo

Theses and Dissertations

Aloe vera (L.) (Aloe) Burm. f., is valued for its applications across the cosmetic, medicinal, and food industries due to its leaf gel. In the aloe industry, the extraction of gel from leaves generates significant quantities of organic waste, which presents an opportunity to repurpose this material as an amendment in aloe cultivation. While Aloe is renowned for its resilience, understanding the feasibility of using these organic shavings as a soil fertility amendment in aloe production is critical. This research aims to identify sustainable fertilization methods for Aloe that can maintain and/or improve crop yield while enhancing soil health. This …

A Nursery Study Of The Interplay Between Soil Texture, Rooting Space, And Nurse Plants On Seedling Growth And Root Development In Woody Species Of Tamaulipan Thornscrub, Lance I. Santos

Theses and Dissertations

Reforestation attempts in semi-arid regions are plagued with seedling mortality. Blanket greenhouse practices may not be optimal, in addition, commensalism interactions between nurse plants are considered. To better understand the effects of soil texture and nurse plant interactions on growth and drought tolerance, two experiments were developed. For soil texture, Border palo verde seedlings were grown in different-sized plant bands with three soil types. To observe the effects of nurse plants, an experiment using guayacan, was developed using Texas Ebony, as a leguminous nurse plant. Plants were also exposed to a drought experiment. The results suggest that some soil textures …

Ecological Effects On Greenhouse Gas Emissions In Vegetated Estuarine Soils Of The Lower Laguna Madre, David R. De La Garza

Theses and Dissertations

Coastal wetlands are important ecosystems that provide numerous ecosystem services including erosion control, habitat for fauna, and carbon sequestration. Notably, coastal wetlands are producers of greenhouse gases (GHGs) but are able to store significant amounts of carbon relative to their surface area. Mangrove forests are amongst the most effective ecosystems for carbon sequestration. Soil emits (GHGs) containing carbon (such as carbon dioxide (CO2) and methane (CH4)), which are produced by organic matter decomposition and soil organic carbon mineralization, and both are an important component of the global carbon cycle. Soil emissions may be affected by a variety of factors including …

Soil Carbon Sequestration Efforts In Arid And Semi-Arid Climates Under Conservation Agriculture And Reforestation, Samantha Lynn Colunga

Theses and Dissertations

Soil organic carbon (SOC) plays a vital role in the global carbon cycle and aids in climate change mitigation. However, deforestation and intensive agricultural practices threaten topsoil and carbon (C) pools through soil disturbances releasing vast amounts of carbon dioxide (CO2) by enhancing the decomposition of organic materials. Degraded soils typically lack stable aggregates, nutrient and water retention, and overall low fertility. In arid and semi-arid regions, soils are in an even more dire situation, as low precipitation and high temperatures slow down the accumulation of SOC. This thesis has two objectives: 1) to evaluate whether conservation tillage practices increase …

Experimental Studies On The Operation Of Agricultural Crops Mowing Unit With Simultaneous Chopping And Incorporation Of Stubble Into The Soil, Volodymyr Nadykto, Sergey Kiurchev, Tatiana Chorna, Taras Hutsol, Szymon Głowacki, Anatoliy Rud, Alona Shevtsova, Igor Ryabov, Katarzyna Szwedziak

Sociology Faculty Publications

For harvesting crops, one-phase and two-phase methods are most often used. When implementing the second one, mounted and trailed units are used. The latter is becoming less and less used due to the problems with movement stability in the horizontal plane because of the asymmetric layout. A stubble background, which is susceptible to solar and wind influences, is formed as a consequence of application of the mounted harvesting unit, As a result, the field’s soil in the inter-swath space intensively loses moisture. A harvesting unit based on a tractor with rear steerable wheels has been designed to eliminate this shortcoming. …

Post-Harvest Eucalyptus Residue Removal Reduces Soil Aggregation And Biological Activities In Central-West Brazil, Karla Nascimento Sena, Thaís Soto Boni, Kátia Luciene Maltoni, Ana Maria Rodrigues Cassiolato, Engil Isadora Pujol Pereira

School of Earth, Environmental, & Marine Sciences Faculty Publications

Tree residue removal from Eucalyptus plantations after timber harvest can reduce soil functioning by reducing the organic matter input. To assess the effects of residue management systems (RMS) on soil aggregation, carbon (C) and nitrogen (N) content, and biological activities, a field trial was conducted in a commercial Eucalyptus plantation (loamy sand soil) in Mato Grosso do Sul, Brazil. The study assessed three RMS: cut-to-length (CTL), tree-length (TL), and bare litter (BL), respectively. After 21 months, undisturbed soil samples were collected and physically isolated into three aggregate-size fractions: large macroaggregates (LM), medium macroaggregates (SM), and microaggregates (MI). Results showed that …

Dynamic Soil Properties In The Lower Rio Grande Valley: Understanding Responses Of Infiltration Rate, Bulk Density, Aggregate Stability To Different Tillage Practices, Temiloluwa Faith Awotoye

Theses and Dissertations

Dynamic Soil Properties (DSPs) are soil properties that change in response to both natural and human-caused interruptions and pressures such as agro-based and wildland management. These soil properties can transform for months or even years in response to the farm use and management procedures. This research project investigates the relationship between different dynamic soil physical properties and tillage practices in the Texas Hidalgo sandy clay loam benchmark soil series. Data analyses was done to compare the effect of tillage to these soil physical properties and build a discussion about relationships between on-farm practices to other aspects of farm viability. We …

Dynamic Soil Properties In The Lower Rio Grande Valley: Carbon And Nitrogen Responses To Different Tillage Practices, Luzyannet Ballesteros Gonzalez

Theses and Dissertations

There has been increased attention in utilizing agriculture for carbon sequestration. Soil carbon and nitrogen are two dynamic soil properties (DSPs) that are indicators of soil health and function and have overlapping cycles. These soil properties change frequently as a result of environmental conditions and agricultural management practices. This study focuses on the impact of tillage practices in unirrigated agricultural fields in Hidalgo and Willacy counties located in South Texas on Hidalgo Sandy Clay Loam; With a particular focus on Soil Total Carbon (TC), Soil Inorganic Carbon (SIC), Permanganate Oxidizable Carbon (POXC), Carbon and Nitrogen ratio (C:N), Soil Organic Matter …

An Assessment Of Physical And Microbial Dynamic Properties Sensitive To Tillage Practices In Hidalgo Sandy Clay Loam Soils, Rocio N. Hernandez

Theses and Dissertations

Mechanized tillage is known to impact the dynamic physical, biological and chemical properties of a given soil, and as a result, can cause systematic harm to the soil’s function (Alam et al., 2014). The aim of this study is to assess how a series of land management tillage practices will impact dynamic physical and biological soil health parameters such as aggregation, carbon, respiration, and enzymatic activity (β-glucosidase). According to Acir et al (2020), the aforementioned soil parameters are both co-influenced and dependent, indicating a response to tillage is likely. A total of 198 samples of Hidalgo series soils were collected …

Grapefruit Peel Biochar Applications For Immobilizing Copper And Lead In Soil, Michael Alfredo Navarro

Theses and Dissertations

This study investigated the efficacy of grapefruit peel (GP) derived biochar materials (two pyrolysis temperatures 450°C and 800°C) as a potential adsorbent to immobilize heavy metal (copper and lead) in a local sandy loam clay soil. A batch adsorption test with heavy metal concentrations at 50 mg L-1, and 100 mg L-1 revealed that soil itself had the highest immobilization percentage compared to the GP biochars. A soil column experiment was conducted to determine how much the GP biochar samples and the tested soil will exhibit adsorptive characteristics for heavy metals when 50 ml of 50 mg L-1 copper or …

Low Soil Nitrogen And Moisture Limit The Expansion Of The Invasive Grass, Megathyrsus Maximus (Guinea Grass) In Semi-Arid Soils, E. Penelope Holland, Vanessa Thomas, Pushpa G. Soti

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

The goal of this study was to predict the range expansion potential of an invasive forage grass, Guinea grass (Megathyrsus maximus). We collected rhizosphere soil samples of M. maximus and coexisting species from 150 different locations and analysed them for soil properties. We estimated the probability of M. maximus presence as a function of soil moisture, organic matter, pH, salinity, total N, and CN ratio using logistic regression. Presence of M. maximus was associated with higher soil moisture, higher organic matter, pH, and nitrogen, but lower salinity and CN ratio. Soil nitrogen and moisture …

Assessment Of Nitrogen-Based Fertilizer Transport And Microbial Activities In Sandy Soil Profiles In South Texas, Gladys De La Rosa

Theses and Dissertations

Conventional farming is a common practice in Lower Rio Grande Valley (LRGV) and the application of nitrogen fertilizer is essential for plant growth and support. However, managing the rate of nitrogen that is applied can benefit farmers financially and reduce nitrate leaching that can have an adverse effect on the local environment and aquatic systems, e.g., rivers and estuaries. Sandy soils are more vulnerable to water infiltration due to the large proportion of macropores. This study aims to (i) assess how nitrate from a variety of fertilizers (i.e., synthetic and organic) distributes on the top 60 cm layer of a …

Cover Crops May Exacerbate Moisture Limitations On South Texas Dryland Farms, Stephanie Kasper, Faeqa Mohsin, Lindsey Richards, Alexis Racelis

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Cover crops are a sustainable management tool for mediating weed pressure, reducing soil erosion, and enhancing soil organic carbon (C) and nitrogen (N) levels. Yet, adoption rates across water-limited farms in Texas remain low, especially among producers without irrigation access, due to concerns that cover crop use of soil moisture will negatively impact subsequent cash crop yields. This three-year cover crop trial in a rain-fed sorghum (Sorghum bicolor L.) farm in Lyford, Texas, trialed different cover crop mixes and seeding rates and confirmed that cover cropping leads to significant soil moisture deficits and cash crop failure when rainfall is low …

Soil Chemistry Modification By Guinea Grass In Semi-Arid Soils: A Litter Mediated Positive Feedback, Vanessa Elizabeth Thomas

Theses and Dissertations

Nutrients are a key component of healthy soils. Their composition plays an important role in plant growth through nutrient cycling and directly influences the functioning of plant communities in both agricultural and natural ecosystems. Shifts in macronutrients such as phosphorus and nitrogen may be initiated by invasive growth as a driver for competition with native plants. The goal of this study is to explore the plant soil feedback in an exotic invasive plant, Guinea grass (Pancium maximum), an invasive bunch grass originally from Africa, across different habitat types in the Lower Rio Grande Valley (LRGV). To determine a positive plant …

Unravelling The Role Of Pgpr "Pseudomonas Fluorescens" In Semi- Arid Soils Of The Rio Grande Valley, Mandip Tamang

Theses and Dissertations

Chapter 1: In this chapter, we have provided a review on the components of rhizosphere engineering and the potential use of PGPR and its challenges to serve as an efficient component for sustainable agriculture.

Chapter 2: In this chapter, we isolated 35 different strains of a PGPR, Pseudmonas fluorescens and characterized various plant growth promoting traits such as production of ammonia, protease, Indole acitic acid (IAA), 1-aminocyclopropane-1-carboxylate deaminase (ACC) deaminase, ammonia, hydrogen cyanide (HCN), and souliblization of zinc and phosphate.

Chapter 3: In this chapter, we tested the influence of plant beneficial soil microbe, P. fluorescens, on the growth and …

Compost And Biochar To Promote Soil Biological Activities Under Sweet Potatoes Cultivation In A Subtropical Semiarid Region, Josabeth Navarro, Jahdiel Salazar, James Jihoon Kang, Jason Parsons, Chu-Lin Cheng, Alexandria Castillo, Engil Isadora Pujol Pereira

School of Earth, Environmental, & Marine Sciences Faculty Publications

South Texas is located in a subtropical semiarid climate, and due to high temperature and irregular precipitation, farmers opt to leave their fields fallow during the summer months jeopardizing overall soil health. We evaluated whether sweet potato (Ipomoea batatas) cultivation coupled with drip irrigation could restore soil biological activities compared with bare fallow. Additionally, because sweet potatoes have high demand of soil nutrients, especially potassium (K), we evaluated the nutrient supply of locally sourced soil amendments. Sweet potato was cultivated during summer 2018 in McAllen, Texas, under control (no fertilizer), NPK (synthetic fertilizer), RC (yard-waste compost), and AC (compost produced …

Predicting Patterns Of Heavy Metal Contamination In Rio Grande Valley Agricultural Soils, Joy Z. Youwakim

Theses and Dissertations

The Rio Grande Valley of Texas is the statewide leader in the production of produce and grains and is irrigated by the Rio Grande River, in which heavy metal contaminants have been documented by both the International Boundary Water Commission and the United States Geological Survey. This work attempts to observe and document patterns of heavy metal pooling in order to mitigate the increased risk of contamination due to urbanization. We hypothesize that relationships exist between heavy metal content and proximity to roads, land use, and soil type. This research tests these relationships through soil sampling and atomic absorption spectrometry …

Soil Biotic And Abiotic Conditions Negate Invasive Species Performance In Native Habitat, Pushpa Soti, Matthew Purcell, Krish Jayachandran

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Background: Most studies on plant invasion consider the enemy release hypothesis when analyzing native habitats. However, the lower performance of invasive species in the native habitats can be the result of unfavorable soil conditions in the native habitats. While soil biotic and abiotic factors have a potential to restrict the growth of invasive species in their native habitats, our understanding of belowground environment of invasive species in their native habitats is very limited. In this study, we analyzed soil characteristics associated with an exotic invasive plant, Old World Climbing Fern (Lygodium microphyllum), in its native habitat in Australia and the …

Soil Indigenous Microbiome And Plant Genotypes Cooperatively Modify Soybean Rhizosphere Microbiome Assembly, Fang Liu, Tarek Hewezi, Sarah L. Lebeis, Vince Pantalone, Parwinder Grewal, Margaret E. Staton

School of Earth, Environmental, & Marine Sciences Faculty Publications

Background: Plants have evolved intimate interactions with soil microbes for a range of beneficial functions including nutrient acquisition, pathogen resistance and stress tolerance. Further understanding of this system is a promising way to advance sustainable agriculture by exploiting the versatile benefits offered by the plant microbiome. The rhizosphere is the interface between plant and soil, and functions as the first step of plant defense and root microbiome recruitment. It features a specialized microbial community, intensive microbe-plant and microbe-microbe interactions, and complex signal communication. To decipher the rhizosphere microbiome assembly of soybean (Glycine max), we comprehensively characterized the soybean rhizosphere microbial …

Improvement Of Soil Structure Through Organic Crop Management, Conservation Tillage And Grass-Clover Ley, Viviana Loaiza Puerta, Engil Isadora Pujol Pereira, Raphaël Wittwer, Marcel G. A. Van Der Heijden, Johan Six

School of Earth, Environmental, & Marine Sciences Faculty Publications

Highlights

• Organic crop management combined with reduced tillage improved soil structure.
• The ley period improved soil structure for conventional intensive tillage.
• The ley period increased total carbon in organic crop management at 0–6 cm soil depth.

Abstract

Conventional intensive tillage is a widespread soil management practice that controls weeds and promotes nutrient mineralization at the expense of a degraded soil structure and soil carbon (C) loss. Alternative soil management practices such as no tillage, reduced tillage and temporary leys, however, can minimize the negative effects of intensive tillage on soil structure. To improve understanding of these management practices on …

Mitigating N2o Emissions From Soil: From Patching Leaks To Transformative Action, C. Decock, Juhwan Lee, M. Necpalova, Engil Isadora Pujol Pereira, D. M. Tendall, Johan Six

School of Earth, Environmental, & Marine Sciences Faculty Publications

Further progress in understanding and mitigating N2O emissions from soil lies within transdisciplinary research that reaches across spatial scales and takes an ambitious look into the future.

Iron-Mediated Stabilization Of Soil Carbon Amplifies The Benefits Of Ecological Restoration In Degraded Lands, Lucas C. R. Silva, Timothy A. Doane, Rodrigo S. Correa, Vinicius Valverde, Engil Isadora Pujol Pereira, William R. Horwath

School of Earth, Environmental, & Marine Sciences Faculty Publications

Recent observations across a 14‐year restoration chronosequence have shown an unexpected accumulation of soil organic carbon in strip‐mined areas of central Brazil. This was attributed to the rapid plant colonization that followed the incorporation of biosolids into exposed regoliths, but the specific mechanisms involved in the stabilization of carbon inputs from the vegetation remained unclear. Using isotopic and elemental analyses, we tested the hypothesis that plant‐derived carbon accumulation was triggered by the formation of iron‐coordinated complexes, stabilized into physically protected (occluded) soil fractions. Confirming this hypothesis, we identified a fast formation of microaggregates shortly after the application of iron‐rich biosolids, …

A Comprehensive Method For Fractionating Soil Organic Matter Not Protected And Protected From Decomposition By Physical And Chemical Mechanisms, César Plaza, José M. Fernández, Engil Isadora Pujol Pereira, Alfredo Polo

School of Earth, Environmental, & Marine Sciences Faculty Publications

The objective of this work was to describe a method for isolating meaningful and measurable soil organic matter (SOM) pools that differ in the mechanisms by which they are protected from decomposition. The proposed method is appropriate for soil C stabilization and sequestration studies. Unlike previous fractionation schemes, this procedure allows free SOM located between aggregates (unprotected C pool) and SOM occluded within both macroaggregates and microaggregates (C weakly and strongly protected by physical mechanisms, respectively) to be recovered separately, freed from the soil mineral matrix and the mineral-associated SOM pool (C pool protected by chemical mechanisms) and thus well …

Comparison Of Soil Chemistry And Microbial Communities That Inhabit The Rhizosphere Of Native And Non-Native Grasses Of The Lower Rio Grande Valley, Jacqueline Valencia

Theses and Dissertations - UTB/UTPA

Non-native grasses can modify the soils they invade. This study investigated microbial variation among native and non-native grasses in the Lower Rio Grande Valley. We hypothesized that rhizospheres of non-native grasses would support a higher density of microorganisms; therefore microbial communities of invasive plants would exploit more carbon sources than those of native plants. A second hypothesis stated that Streptomyces bacteria from the rhizosphere of non-native grasses would be better competitors. Samples of grasses, and soil from their respective rhizospheres were obtained in Arroyo City, TX. Results indicated a higher bacterial colony density, total activity and number of substrates utilized …

Soil Nitrogen Transformations Under Elevated Atmospheric Co2 And O3 During The Soybean Growing Season, Engil Isadora Pujol Pereira, Haegeun Chung, Kate Scow, Michael J. Sadowsky, Chris Van Kessel

School of Earth, Environmental, & Marine Sciences Faculty Publications

We investigated the influence of elevated CO2 and O3 on soil N cycling within the soybean growing season and across soil environments (i.e., rhizosphere and bulk soil) at the Soybean Free Air Concentration Enrichment (SoyFACE) experiment in Illinois, USA. Elevated O3 decreased soil mineral N likely through a reduction in plant material input and increased denitrification, which was evidenced by the greater abundance of the denitrifier gene nosZ. Elevated CO2 did not alter the parameters evaluated and both elevated CO2 and O3 showed no interactive effects on nitrifier and denitrifier abundance, nor on total and mineral N concentrations. These results …