Conservation Drainage Drainage for the 21 st Century

Conservation Drainage: Drainage for the 21 st Century

The Nitrate Saga 1890 s Scientists sound alarm about need for new source of nitrates

Fritz Haber Carl Bosch

Nutrient contributions to the Gulf, by State

Distribution of Subsurface Tile Drainage in Illinois 3 -4 million ha (6 -10 million acres) drained with subsurface tile in Illinois This comprises some of the most productive agricultural land in the US.

HYDROLOGIC CYCLE (with tiles)

7. 2 km/km 2

Mutabaruka The solutions that you seek will not be found in the streak of a pen, or even one thousand words of mine.

Nitrate Reduction Techniques Altering Nitrogen Application Amounts Altering Nitrogen Application Timing Edge-of-Field Treatment Optimizing Drainage System

Conservation Drainage The incorporation of environmentally friendly practices and structures into existing drainage infrastructure Minnesota Department of Agriculture

Conservation Drainage The optimization of drainage systems for crop production, water quality and water harvesting benefits

ts ec Eff s rse or ve hb Ad Neig De cre as Eff e i ici n D en rai cy na ge No Drainage Water Management Depth/Spacing Modifications Convenient and Cost. Effective on No Conservation Drainage Subsurface Bioreactors

Golden Rule of Drainage • Only release the amount water necessary to insure trafficable conditions for field operations and to provide an aerated crop root zone – any drainage in excess of this rule likely carries away nitrate and water that is no longer available for crop uptake

Drainage Water Management

Manual Gate Structure Automated Gate Structure Float Structure

Drainage Water Management Guidelines – in an unusually dry season, control can be 3 to 6 inches higher; – in an unusually wet season, control should be 3 to 6 inches lower; – in coarse-textured soils, trafficability can be provided with the water table approximately 6 inches higher.

Managed Drainage - Winter Conservation Mode for Fallow Season

Managed Drainage - Spring Full Drainage Mode for Planting Season

Managed Drainage -Summer Shallow Drainage Mode for Growing Season

Managed Drainage - Fall Full Drainage Mode for Harvest Season

Potential Water Available from Drainage Management ~ 1. 5 inches Source: Based on DRAINMOD Simulations

Water Deficit Stress

DWM Benefits • Reduces Nitrate Concentrations in Effluent – 30 -95% reductions annually • Increased Yield – 76% higher yield in a dry year • Lower Concentrations of Other Pollutants

Required Information for Economic Analysis of DWM System • Drainage Costs • Added Revenue • Capital Costs • Timeliness Benefits

Drainage Water Management

Hume 2004

Flow Depths (cm) From a Paired Drainage Site Free Drainage Managed Drainage

Hume 2006

Long Term Nitrate Trends: 2005

Long Term Nitrate Trends: 2008

Free Drainage 11. 3 acres 50 -70 ft Spacing Managed Drainage 13. 1 acres 50 -70 ft Spacing

Nitrate-N (mg/L) Kinderhook Site

System Layout for Drainage Water Management

Layout Costs Cost Differential: $50/acre