Direct Seed Movement Gains Momentum with 1998 NW Conference

Chapter 2 – Conservation Tillage Systems and Equipment, No. 22 (Updates No. 19), May 1998

Author: Roger Veseth, WSU/UI Extension Conservation Tillage Specialist

There’s been a phenomenal increase in the use of direct seeding systems and more diverse crop rotations across the Northwest, America and around the world. Nearly 900 Northwest growers and Ag advisers attended the first Northwest Direct Seed Intensive Cropping Conference on January 7-8, 1998 in Pasco, WA. The Conference would have been even larger, but registration had to be restricted because of space limitations. What is behind this huge interest in direct seeding and alternative cropping systems?

Some important factors driving these changes include: 1) increasing global market competition and the need to reduce costs and improve profitability; 2) new crop rotation flexibility under the 1996 Farm Program; 3) increasing grower and public concern about cropland soil loss by water and wind erosion; 4) greater awareness of the soil quality and productivity benefits of direct seeding and detriments of intensive tillage; and 5) significant advances in management and equipment technologies for direct seeding. The following provides some examples and further explanation.

Competing with the Competition 

This is the name of the game as NW growers move into an increasingly global marketplace. Direct seeding and other minimum tillage systems offer the potential to reduce production costs and increase profitability.

Some examples of 1997 statistics may help provide some insight into how our national and international competitors are moving towards direct seeding system. The 5% of PNW cropland was under no-till direct seed systems pales in comparison to the U.S. average of 16%, Brazil – 15%, Canada – 18%, Argentina – 28% and western Australia – 30%.
A brief review of the rapid trend towards no-till in Argentina helps illustrate the tremendous growth in no-till direct seed systems. In 1990, there was less than 2% of Argentina’s cropland in no-till. That grew to 6% in 1993, 19% in 1996, and 28% in 1997, which is nearly 15 million acres. The 5% of Northwest cropland under no-till in 1997 is about the same as Argentina’s 6% in 1993. You could say that we are about four years behind Argentina in adopting more efficient farming technologies. Western Australia is another striking example, growing from 0.1% in 1989 to over 30%, about 10 million acres, in 1997. There are similar trends around the world.

The potential advantage of direct seeding on production efficiency was quite striking on a June 1997 Northwest grower tour in South Dakota. A direct seeding grower was farming about 10,000 acres with two implements, a 100′ sprayer and 60′ no-till air drill. Custom harvesters did the combining. It would be interesting to compare the input costs of their two-pass operation with the same size farm under conventional tillage, looking at the number of tractors and implements needed, equipment maintenance, fuel, labor and other production costs. If we are going to compete economically, we need to explore the production efficiency potential of direct seeding and other minimum tillage systems.

New Rotation Flexibility

The 1996 “Freedom to Farm Bill” finally gave growers the cropping flexibility needed to develop crop rotations critical to the success of direct seeding systems. For more than 50 years, U.S. Farm Bills have been major obstacles to successful no-till and minimum tillage systems in the Northwest and across the country. Commodity program restrictions largely locked Northwest dryland growers into short crop rotations in order to maintain their wheat base acreage, and high proven yields for winter wheat. To manage weeds and diseases, they were forced to rely on intensive tillage. Early NW attempts at no-till beginning in the 1970’s, in their traditional 2-year rotations with winter wheat, often resulted in reduced yields or crop failures due to soilborne diseases and winter annual grass weeds. At that time there was also little research base or grower experience to guide growers in managing these new conservation tillage systems.

Effective Soil Erosion Control 

Water and air quality are becoming more important issues, so the urgency for cropland erosion control will increase. It is well documented by research and grower experience worldwide that direct seeding systems can effectively reduce or totally eliminate water and wind erosion. It is important, however, that all crops in the rotation be managed under direct seeding or other minimum tillage systems to optimize erosion control and soil productivity benefits.

New Insights into Tillage Impacts and Direct Seeding Benefits 

The results of recent research and long-term grower experiences in North America and around the world are revolutionizing our understanding of the impacts of tillage on soils. Contrary to the long-held belief that returning crop residue to the soil with tillage builds soil organic matter, the real impact of intensive tillage systems is a continual decline in soil organic matter content. Organic matter is a critically important soil component directly related to soil fertility, water holding capacity and infiltration, aggregation and structure, erodibility, biological activity and a long list of other soil properties affecting soil productivity and soil quality.

The increased oxygen level and higher soil temperature present after tillage stimulate intense microbial activity under moist soil conditions. A tremendous amounts of carbon can be released as carbon dioxide during this accelerated microbial decomposition of soil organic matter. The end result is that tillage is biologically burning off soil organic matter faster than it can be built with the addition of new crop residues.

Research shows that no-till direct seeding systems result in very low carbon loss compared to intensive tillage, consequently offering the greatest potential for increasing soil organic matter content over time. The greater and more frequent the soil disturbance, the greater the carbon loss potential. With improved water conservation under direct seeding there is a corresponding higher yield potential. For wheat, it is around 5 to 7 bushels/acre per inch of additional water. The challenge for growers and Ag support personnel is to develop the crop rotations and management systems to control of pests previously controlled by intensive tillage in order to take advantage of the higher yield potential.

New Direct Seeding Technologies 

There have been some significant technology advances since Northwest growers began trying no-till drills in the 1970’s. Many of the pest problems that occurred during the past 30 years can now be largely avoided because of new research technologies. Here are a few important examples.

Longer, more diverse crop rotations have been shown to be very effective in controlling weeds, diseases and insect pests that often occur in direct seed systems under short crop rotations. Northwest growers, researcher, and industry representatives are scrambling to find profitable alternate crops and crop rotations for the different production areas of the region.

Another big technology advance was identifying the impact and management of the “Green Bridge,” which has been a major cause of crop failures or sharply reduced yields in direct seeded spring crops in the Northwest for over 25 years. Northwest research showed that the short time interval between spraying a non-selective herbicide on volunteer and weeds before direct seeding created a “green bridge” for root diseases and some insects to attack the new crop. It can be effectively eliminated by spraying as early as possible before seeding, beginning in the fall if possible, and early spring at least three weeks before seeding. After this early control, late spraying of very low populations of small, late-emerging weeds and volunteer just before seeding will then have little “green bridge” potential for root disease. Uniform distribution of chaff from the combine is also an important starting point in managing the green bridge and other concerns in direct seeding.

Research developments on seeding equipment designs for fertilizer and seed placement have revolutionized equipment for direct seeding. In the early 1970’s, there were only about 5 models of “no-till” drills available in the Northwest, none of which had deep fertilizer banding capability. Research has shown that deep fertilizer placement below seed depth and near the seed row can significantly improve yield potential under direct seeding, particularly with cereals after cereals. Today there are over 40 drill models, nearly all with deep fertilizer placement options. Improvements are still needed in hillside performance and residue handling capabilities under some Northwest conditions, but grower now have a large variety of equipment options. There are also numerous examples of excellent grower and industry equipment modifications to improve performance of direct seeding equipment in the region.


Pacific Northwest Conservation Tillage Handbook Series publications are jointly produced by University of Idaho Cooperative Extension System, Oregon State University Extension Service and Washington State University Cooperative Extension. Similar crops, climate, and topography create a natural geographic unit that crosses state lines in this region. Joint writing, editing, and production prevent duplication of effort, broaden the availability of faculty, and substantially reduce costs for the participating states.

For herbicide application recommendations, refer to product labels and the Pacific Northwest Weed Control Handbook, an annually revised extension publication available from the extension offices of the University of Idaho, Oregon State University and Washington State University. To simplify information, chemical and equipment trade names have been used. Neither endorsement of named products is intended, nor criticism implied of similar products not mentioned.

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