What Every CCA Should Know About Drainage

Within the cornbelt of the U.S. the use of subsurface drainage systems has been important and perhaps essential in the development of the current agricultural production systems. How water is managed relative to subsurface drainage not only impacts crop production but can also impact the quality and quantity of the water leaving the agricultural field. As a result it is important to understand how subsurface drainage implementation, design, and management may impact crop production and water. This paper and presentation will discuss how subsurface drainage works, how drainage design relative to drain sizing and spacing may impact crop production, and how new technologies for managing drainage water may provide both production and water quality benefits. In addition, some of the commonly held myths about subsurface drainage will be discussed

Nutrient reduction strategy: One farm, many practices

With the release of the Iowa Nutrient Reduction Strategy (2013) in early 2013 there has been increased interest in what practices can be utilized by farmers to reduce nutrient export to downstream water bodies. As highlighted by the ISU Extension and Outreach Special Publication 235 (2013) there are many in-field, land use, and edge-of-field practices that have potential to reduce nutrient export. However, to reach the nutrient load reduction goals of 45% on both nitrate-N and phosphorus will require a combination of practices. As a result, there is a need to examine individual fields or small watersheds considering the range of practices to assess how the practices can be combined to reach the desired outcomes. In this paper, we consider a case study watershed of about 1200 acres and examine individual and combinations of practices to reduce nitrate-N export from this area

Extending field scale 4R nutrient management and wetland performance to watershed scale outcomes

Much of the U.S. Corn Belt is characterized by relative flat, poorly-drained areas which with extensive subsurface drainage, have become some of the most valuable and productive agricultural land in the world. However, this is not without consequences. Nitrate-N loss from these systems is of particular concern due to its potential adverse impacts on both public health and ecosystem function. In addition to the potential local impacts on receiving waters in the Corn Belt, nitrogen loads from the region are suspected as a primary contributor to hypoxia in the Gulf of Mexico. Iowa has long been a leader in balancing agricultural production and water quality concerns and in 2013 the Iowa Department of Agriculture and Land Stewardship released a nutrient reduction strategy in response the 2008 Gulf of Mexico Hypoxia Task Force Action Plan

Impacts of 4R nitrogen management on drainage water quality

Much of the U.S. Corn Belt is characterized by relative flat, poorly-drained areas which with extensive subsurface drainage, have become some of the most valuable and productive agricultural land in the world. However, this is not without consequences. Nitrate-N loss from these systems is of particular concern due to its potential adverse impacts on both public health and ecosystem function. In addition to the potential local impacts on receiving waters in the Corn Belt, nitrogen loads from the region are suspected as a primary contributor to hypoxia in the Gulf of Mexico. For nearly 30 years Iowa State University has been studying the impacts of nitrogen and land management practices on drainage water quality at a variety of sites throughout the state

Cover crops, bioreactors, and wetlands for nitrate reduction

With the release of the Iowa Nutrient Reduction Strategy in early 2013 there has been increased interest in what practices can be utilized by farmers to reduce nutrient export to downstream water bodies. As highlighted by the ISU Extension and Outreach Special Publication 235 (2013) there are many in-field, land use, and edge-of-field practices that have potential to reduce nutrient export. Three practices that have garnered a substantial amount of interest are cover crops, bioreactors, and wetlands. These three practices span the scale from in-field (cover crops) to edge-of-field (bioreactors) to watershed scale (wetlands)

Integration of water, nutrient an carbon cycling under diverse annual perennial plant community systems in agricultural landscapes

This study examined nutrient, water and carbon cycling processes and biodiversity patterns within replicated sub-watersheds that comprised different configurations of annual and perennial plant communities, ranging from conventional row crops to mixed annual and perennial systems to reconstructed native plant communities

Drainage design for improved profits and water quality

Subsurface drainage systems are an important component of agricultural production systems in many areas of Iowa. However, these drainage systems have been shown to deliver nitrate-N to downstream waterbodies. So, while subsurface drainage is important for crop production we also need to consider the design of these systems to minimize nitrate-N loss. Use of drainage water management in the design and operation of subsurface drainage systems is one potential method to reduce nitrate-N loss