Course Overview

The objective of this course is to provide specialized training to professionals on conventional and recently developed techniques to evaluate soil phosphorus dynamics in Florida watersheds. The course includes topics such as determination of various forms of phosphorus in soils and how Florida soils interact with phosphorus. The application of conventional and recently developed techniques for understanding phosphorus retention and loss from soils that would impact the quality of water leaving a farm or a watershed will be discussed. Examples of using the newer techniques for understanding and solving real-world problems will be provided.

Course Format

The course will consist of six modules covering different aspects of soil phosphorus assessment and dynamics. Each module will include five approximately 15-minute lectures that focus on a particular topic. At the end of each lecture, references will be provided (when applicable) to enable participants to enhance their understanding of the topic. Each of the lectures can be accessed individually.

Who Could Benefit?

Participants interested in or actively involved in phosphorus management and water quality issues in Florida watersheds. Anyone seeking rigorous training in management of phosphorus-amended soils would likely benefit by completing these course materials, but particularly those employed in the following occupations:

• Academics and Educators
• Agricultural and Environmental Engineers
• Soil Surveyors
• Ecologists, Foresters, Soil Scientists, Water Scientists, Environmental Scientists
• Environmental Consultants
• Environmental Regulators
• Land Use Planners and Developers
• City and County Government Officials and Decision Makers

Course Instructors

Vimala Nair is a Research Professor at the Soil and Water Sciences Department of the University of Florida, Institute of Food and Agricultural Sciences (IFAS). She is an environmental soil chemist with over 25 years of experience working on phosphorus issues in Florida. Her research has concentrated on soil-P interactions as they relate to fate and transport of phosphorus from agricultural lands, and water quality implications of excess phosphorus applications.

Willie Harris is a Professor at the Soil and Water Sciences Department of the University of Florida with more than 30 years of experience on research related to mineral stability and transformations in soils and sediments. His more recent research addresses soil components, amendments and processes affecting phosphorus transport.

Course Outline and Links to Lectures

Course Introduction

Module 1: Welcome, Course Overview, and Conventional Techniques for Evaluating Phosphorus (P) Release from Soils

Lecture 1: Welcome and course overview
Lecture 2: Sampling soils for P risk assessment
Lecture 3: Conventional techniques for evaluating phosphorus release from soils - water soluble P and soil test P
Lecture 4: Oxalate-extractable P, iron-oxide strip P, and total P
Lecture 5: Soil phosphorus fractionation procedures

Module 2: How Florida Soils Interact with Phosphorus

Lecture 1: Overview of Florida soils and their distribution
Lecture 2: P dynamics as related to soil morphology and composition I
Lecture 3: P dynamics as related to soil morphology and composition II
Lecture 4: Soil & hydrologic factors affecting P transport
Lecture 5: Risk-assessment implications of manure-amended, fertilizer-amended, and naturally-phosphatic soils

Module 3: Use of Conventional Techniques for Evaluating Phosphorus in Soils

Lecture 1: Isotherm determination
Lecture 2: Applications of fractionation and isotherm parameters
Lecture 3: P retention and release from biochar
Lecture 4: The Phosporus-Index (P-Index)
Lecture 5: The Quick P Field Test

Module 4: Recent Developments in Techniques for Evaluating Phosphorus Release from Soils

Lecture 1: Degree of P saturation & the P saturation ratio: Theory and calculations
Lecture 2: Degree of P saturation & the P saturation ratio: Examples from literature
Lecture 3: The P saturation ratio (PSR) and isotherm parameters
Lecture 4: Soil phosphorus storage capacity (SPSC)
Lecture 5: Relating recently developed techniques (PSR & SPSC) to existing data

Module 5: Phosphorus Storage and Release from P-impacted Soils

Lecture 1: Long-term contribution of phosphorus from agricultural lands: “legacy” P
Lecture 2: Inorganic vs organic sources of P
Lecture 3: Reduction of P loss from a soil through amendment additions
Lecture 4: Natural and anthropogenic sources of P
Lecture 5: Risk assessment of wetland soils

Module 6: Other Applications of the PSR and SPSC Concepts

Lecture 1: Environmental and agronomic applications
Lecture 2: Site-specific prediction of P loss risk
Lecture 3: Phosphorus storage and release in tree-less and tree-based agricultural systems
Lecture 4: Relationship of PSR and SPSC to edge-of-field and groundwater quality
Lecture 5: Overview of the PSR & SPSC concepts