The development of the field-scale Erosion Productivity Impact Calculator (EPIC) model was initiated in 1981 to support assessments of soil erosion impacts on soil productivity for soil, climate, and cropping conditions representative of a broad spectrum of U.S. agricultural production regions....

The Agricultural Policy Environmental eXtender (APEX) model was developed by the Blacklands Research and Extension Center in Temple, Texas. APEX is a flexible and dynamic tool that is capable of simulating a wide array of management practices, cropping systems, and other land use across a broad...

Assessing the effects of alternative policies that regulate nonpoint pollution from concentrated animal feeding operations (CAFOs) requires insight into the interactions of livestock production practices, waste management technologies, and their impacts on the environment. CAFOs have been...

The interactive APEX (i_APEX) is a user friendly interface for the physical process and environmental fate model, Agricultural Policy/Environmental eXtender (APEX) (Williams et al., 2006, 2008; Williams and Izaurralde, 2006; Gassman et al., 2010). I_APEX is programmed in C++ and performs automatic...

A tool for managing large numbers of APEX runs, handling data input and output. Program Components: • ACCESS Database: Contains input tables used by i_APEX to construct APEX runs and output tables to organize APEX output. • Graphical User Interface: Allows for single runs and ranges...

In this paper, we discuss the importance of developing integrated assessment models to support the design and implementation of policies to address water quality problems associated with agricultural pollution. We describe a new modeling system, LUMINATE, which links land use decisions made at...

The purpose of this review and analysis is to provide a basic understanding of the issues related to worldwide hypoxic zones and the range of economic questions sorely in need of answers. We begin by describing the causes and extent of hypoxic zones worldwide, followed by a review of the...

This study investigates the implications of treating different environmental benefits as the primary target of policy design. We focus on two scenarios, estimating for both of them in-stream sediment, nutrient loadings, and carbon sequestration. In the first, we assess the impact of a program...