- Board leadership series planned for March (1/24/13)
- Extension resources available (1/3/13)
- Cold weather clothing for farm safety (12/13/12)
- Best firewood bargains may not be cheap (11/21/12)
- Join the club (10/11/12)
- Plan ahead for meetings (9/20/12)
- Historical climatologist studies effects of drought (8/30/12)
Terrace evaluation and maintenance time
Thursday, November 10, 2011
Now that much of the corn, soybeans and grain sorghum have been harvested, it's a good time to evaluate and perform maintenance on terraces. The long period of dry, mild fall weather has helped create ideal conditions in many areas for terrace maintenance.
To accomplish their purpose for erosion control and save water, terraces must have adequate capacity, ridge height and channel width. Without adequate capacity to carry water, terraces will be overtopped by runoff in a heavy storm.
Overtopping causes erosion of the terrace ridge, terrace back slope and lower terraces and may result in severe gullies. Terraces are typically designed to handle runoff from a one-in-10-year storm -- those that have a 10 percent chance of occurring in any one year.
Terraces need regular maintenance to function for a long life. Erosion by water, wind and tillage wears the ridge down and deposits sediment in the channel, decreasing the effective ridge height and channel capacity.
The amount of capacity loss depends on the type and number of tillage operations, topography, soil properties, crop residue and precipitation. Terrace maintenance restores capacity by removing sediment from the channel and rebuilding ridge height.
Check terraces and terrace outlets regularly (at least annually) for needed repairs. The best time to check is after rains when erosion, sedimentation and unevenness in elevation are easiest to spot. Specific items to note are overtopping, low or narrow terrace ridges, water ponding in the channel, terrace outlets, erosion and sediment clogging near waterway or pipe outlets.
Conservation tillage and crop rotations that retain crop residue will reduce erosion substantially. This will reduce the frequency of terrace maintenance needs.
Many no-till producers find terrace systems require little maintenance. Although runoff still occurs, there is very little soil movement in a no-till system.
Terraces should be considered only a part of an overall erosion control plan. Use of conservation farming methods -- especially residue maintenance -- compliments erosion control structures and has been shown to be both economically and environmentally sound.
Terrace Maintenance is available from K-State Research and Extension, document C-709.
Additional sources for technical information include local USDA -- Natural Resources Conservation Service and county conservation district offices.