Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


franks final.pdf (2.68 MB)

ETD Abstract Container

Abstract Header

The Role of Soil Organic Matter and Fe- and Mn-(Oxy)Hydroxide Minerals in Agriculture: Implications on Nutrient Dynamics

Franks, Matthew James
http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1594151828787397

Abstract Details

2020, Master of Science (MS), Bowling Green State University, Geology.
Conventional tillage, a soil preparation practice to produce a fine seedbed, can disturb the soil profile by promoting soil compaction and soil organic matter (SOM) degradation. In contrast, conservation tillage, such as no-till and minimal tillage (30% or more crop residue) have the potential to sustain or increase soil organic carbon (SOC). Additional benefits of conservation tillage include; improvement to soil structure, reducing soil erosion, greater water retention, buffering soil temperatures, and greater crop residue retention. Conservation tillage practices promote nutrient retention in soils. Furthermore; Fe- and Mn-(oxy)hydroxide minerals play an important role in SOC stabilization and sequestration, which also promotes nutrient adsorption. This study aimed to 1) quantify SOC under varying agricultural managements, 2) qualitatively describe the degree of aromaticity and recalcitrance of SOC using fluorescence spectroscopy, 3) correlate SOC quantity with nitrogen and phosphorous retention in soils, and 4) understand the mineral phases responsible for the stabilization and sequestration of SOC, as well as phosphate and nitrate using a four-step chemical sequential extraction. Results showed that no till and minimal tillage sites consistently had greater SOC and fluorescence intensity in the humic-like acids region, when compared to conventional tilled fields. The SOC quality was obtained using relatively quick and cost-effective methods. No till and minimal tillage enhanced SOC stabilization. In addition, conservation tillage practices retained the largest total nitrogen and total phosphorous concentrations at all studied depths (0-30 cm), when compared to conventional tilled fields. Sequential extraction results showed that SOC was stabilized in the following order: crystalline Fe-oxides > amorphous Fe-oxides > Mn-oxides. Fe- and Mn-(oxy)hydroxide minerals can promote the stabilization and long-term sequestration of SOC via the formation of inner sphere complexes (e.g., ligand-exchange) within the mineral surfaces contact zone. Fe- and Mn-(oxy)hydroxide minerals adsorbed PO4-3 species to a large extent; however, NO3- was adsorbed marginally. Results indicated that PO4-3 adsorption is largely mediated by the Fe- and Mn-(oxy)hydroxide minerals, and NO3- by bulk SOM. The complex relationship between SOM, PO4-3, NO3-, and Fe- and Mn-oxides, is needed to be fully understood in order to successfully and efficiently operate an agricultural practice within a changing environment.
Angélica Vázquez-Ortega, Dr. (Advisor)
Andrew Gregory, Dr. (Committee Member)
Ganming Liu, Dr. (Committee Member)
97 p.
Geology
Soil Organic Matter; CEC; Dissolved Organic Matter; Soil Organic Carbon; Dissolved Organic Carbon; Phosphate; Phosphorus; Nitrate; Nitrogen; Mn; Fe; oxides; nutrient management; mineral phases; fluorescence spectroscopy; agriculture; BMP

Recommended Citations

Citations

  • Franks, M. J. (2020). The Role of Soil Organic Matter and Fe- and Mn-(Oxy)Hydroxide Minerals in Agriculture: Implications on Nutrient Dynamics [Master's thesis, Bowling Green State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1594151828787397

    APA Style (7th edition)

  • Franks, Matthew. The Role of Soil Organic Matter and Fe- and Mn-(Oxy)Hydroxide Minerals in Agriculture: Implications on Nutrient Dynamics. 2020. Bowling Green State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1594151828787397.

    MLA Style (8th edition)

  • Franks, Matthew. "The Role of Soil Organic Matter and Fe- and Mn-(Oxy)Hydroxide Minerals in Agriculture: Implications on Nutrient Dynamics." Master's thesis, Bowling Green State University, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1594151828787397

    Chicago Manual of Style (17th edition)

bgsu1594151828787397
244
© 2020, all rights reserved.
This open access ETD is published by Bowling Green State University and OhioLINK.