Options abound for sub-surface drainage management

Sub-surface drainage is vital to agricultural productivity. It’s also important to manage to ensure nutrients do not escape into the drains.

In August, the Michigan Land Improvement Contractors Association and MSU Extension held a farm drainage and nutrient management field demonstration in Jonesville, Mich., near the Ohio and Indiana borders. Bruce and Jennifer Lewis hosted the event at their Pleasant View Dairy. Nearly 1,000 farmers and contactors came from all over the tri-state area and beyond.

In-field demonstrations included a sub-surface irrigation system, a wood chip bio-reactor, water control structures and land shaping. Educational sessions and demonstrations showcased new tillage equipment, cover crops and nutrient management.

The goal of the field day was to create awareness of options in both new technologies related to drainage systems and management practices that can be employed to reduce losses of nutrients to surface waters, improve yields and reduce the risks of uncertain weather events. Soil types, slopes and producer goals will determine which option will work best on any individual farm.

Four new drainage machines were on site installing a contour drainage and sub-irrigation system, while Dr. Richard Cooke from the University of Illinois guided the installation of a bio-reactor. Dr. Larry Brown of Ohio State University and Phil Algreen from Agri Drain demonstrated and explained how water control structures could be used for controlled drainage, and Nate Cook from AGPS demonstrated land shaping with GPS outfitted bulldozers. Larry Geohring from Cornell University came from New York to speak about proactive management practices to keep manure out of sub-surface drainage systems.

Bark bed bio-reactors remove nitrogen in drainage water before it is released to surface waters. Bio-reactors can be applied to existing systems and can be installed without losing land from production. Water control devices control the water level in the soil and ultimately create less outflow of water during the non-growing season and therefore, less loss of nutrients. True sub-irrigation manages the water table over the growing season, and additional water can be added through the sub surface tile system during dry periods and thus increase yields. A subsurface drainage system helps manage risk in this era of variable weather patterns.

Along with ensuring successful yields and timely field operations, the management practices displayed during the field tour also included the latest in tillage methods and tools such as vertical tillage, cover crops and their use in combination with manure applications. Tile drains are designed to drain water, and when manure is liquid enough, it acts like water. Shallow tillage operations prior to liquid manure applications can disrupt the macro-pores and cause manure to be adsorbed and held in the soil rather than reaching subsurface drains while conserving surface crop residue. Tillage is one option that is readily available on most farms. Cover crops assist in absorbing, retaining and recycling manure and fertilizer nutrients. Bio-reactors and water control devices provide added protection of surface waters if crop nutrients do reach tile drains.

Field day participants got to see, listen and discuss the options available, and interact with resource people to determine what practices might be most applicable for their farming operation.

Related Articles