Conservation Tillage and Direct Seeding Operations

Traditional farming practices typically involve aggressive soil disturbance through numerous passes over the field. This leaves the soil unprotected by crop residue and susceptible to erosion from wind and water. Conventional tillage also leads to a loss of soil moisture and organic matter in the soil. The loss of fertile soil itself will reduce the productivity of farmland. It also results in sediment, fertilizers and pollutants reaching waterways, impacting water quality and wildlife habitat.

Direct seeding equipment creates minimal disturbance when placing the seed and fertilizer in the soil.

Direct seeding and other conservation tillage practices are much less intensive. The techniques typically fertilize and plant directly into undisturbed soil in only one or two field operations. The bulk of the residue from previous crops is retained on the soil surface. Seed is planted directly into this residue disturbing only a narrow strip of soil. The reduced soil disturbance and retention of surface crop residues protects the environment while also increasing soil productivity and retaining soil moisture. Farmers also benefit from reduced production costs through reduced labor and fuel use.

The benefits are numerous, including:

• Improves soil tilth - A no-till system increases soil aggregation (small soil clumps) making it easier for plants to establish roots and minimizing compaction. Compaction is also reduced due to fewer trips across the field.
• Traps soil moisture to improve water availability - Keeping crop residue on the surface traps water in the soil and reduces evaporation. Residue also acts as tiny dams, slowing runoff and allowing water to soak into the soil.
• Reduces soil erosion - Crop residues on the soil surface reduce erosion by water and wind. Depending on the amount of residues present, soil erosion can be reduced by up to 90% compared to an unprotected, intensively tilled field.
• Improves water quality - Crop residue helps hold soil along with associated nutrients (particularly phosphorus) and pesticides on the field to reduce runoff into surface water.
• Improves air quality - Crop residue left on the surface improves air quality through reduced wind erosion. Air quality is also improved due to fewer emissions from farm tractors making fewer trips across the field.

The differences between conservation tillage/direct seeding and conventional tillage are often obvious. These pictures were taken on the same day, after a week of rain. Left: A field seeded using direct seeding operations. Straw residue from the previous crop remains on the field. The new crop can be seen emerging through the straw. Some water can be seen on the surface, but most has been absorbed where it will be available to the crop. There is no erosion, despite the heavy rain and the slope of the field. Right: A field farmed using conventional techniques. The rain has not been absorbed into the field. Instead, it has eroded top soil from the higher areas. The water has run down into a low area, creating a large muddy pool. Both the erosion and muddy pool will damage and potentially kill the crop. Water quality may also be impaired should the water find its way to a stream.

Additional Resources:

SCCD's Production Ag Manager, Ty Meyer, is available to address questions concerning conservation tillage and direct seeding operations. He can also provide information on the District's low-interest loan program for the purchase of conservation tillage equipment. You can reach Ty at (509) 535-7274.

Pacific Northwest Direct Seed Association is a grower-based organization working to increase the use of direct seed farming operations. The 2007 Direct Seed Conference "The Direct Seed Advantage in Dryland and Irrigated Cropping Systems" will take place January 10-12, 2007 at the Three Rivers Convention Center in Kennewick, Washington.

STEEP (Solutions to Environmental and Economic Problems) is an organization focusing on developing profitable cropping systems technologies for controlling cropland soil erosion and protecting environmental quality. STEEP is a collaborative project involving scientists and educators from the University of Idaho, Oregon State University, Washington State University, and USDA-Agricultural Research Service, in cooperation with grower organizations and agricultural support industries and agencies.

< top of page >