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Full-Text Articles in Physical Sciences and Mathematics

The Cation Exchange Behavior Of Tylosin In Loess-Derived Soil, Jaime J. Call, Michael E. Essington, Sudipta Rakshit Jun 2019

The Cation Exchange Behavior Of Tylosin In Loess-Derived Soil, Jaime J. Call, Michael E. Essington, Sudipta Rakshit

Agricultural and Environmental Sciences Faculty Research

Tylosin (Tyl) is a veterinary antibiotic commonly used in swine and poultry production. Due to metabolic inefficiencies, it enters the environment through manure applications. Ion exchange is an important retention mechanism for Tyl, particularly for smectite clay. The objectives of this study are to characterize the exchange interactions of Tyl with common soil cations in subsoil horizons that contain smectite and to investigate the interactions using in situ Fourier transform infrared (FTIR) spectroscopy. Adsorbed Tyl in pH neutral, smectitic subsoil horizons is divided into exchangeable and nonexchangeable forms. The percentage of adsorbed Tyl that is exchangeable varies from 36% to …


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 Apr 2019

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 …


Experiment Study Of Lateral Unloading Stress Path And Excess Pore Water Pressure On Creep Behavior Of Soft Soil, Wei Huang, Kejun Wen, Dongsheng Li, Xiaojia Deng, Lin Li, Haifei Jiang, Farshad Amini Jan 2019

Experiment Study Of Lateral Unloading Stress Path And Excess Pore Water Pressure On Creep Behavior Of Soft Soil, Wei Huang, Kejun Wen, Dongsheng Li, Xiaojia Deng, Lin Li, Haifei Jiang, Farshad Amini

Civil and Architectural Engineering Faculty Research

The unloading creep behavior of soft soil under lateral unloading stress path and excess pore water pressure is the core problem of time-dependent analysis of surrounding rock deformation under excavation of soft soil. The soft soil in Shenzhen, China, was selected in this study. The triaxial unloading creep tests of soft soil under different initial excess pore water pressures (0, 20, 40, and 60 kPa) were conducted with the K0 consolidation and lateral unloading stress paths. The results show that the unloading creep of soft soil was divided into three stages: attenuation creep, constant velocity creep, and accelerated creep. The …


Sampling Soils In A Heterogeneous Research Plot, Jianwei Li Jan 2019

Sampling Soils In A Heterogeneous Research Plot, Jianwei Li

Agricultural and Environmental Sciences Faculty Research

Soils are highly heterogeneous. In general, the number of soil samples required for soil research has always been determined arbitrarily and the associated accuracy is unknown. Here, we present a detailed protocol for efficient and clustered soil sampling in a research plot and, relying on a pilot sampling using this design, for demonstrating soil spatial heterogeneity and informing reasonable sample sizes and associated accuracy for future study. The protocol mainly comprises four steps: sampling design, field collection, soil analysis, and geostatistical analysis. The step-by-step procedure is modified according to former publications. Two examples will be presented to demonstrate contrasting spatial …