Return to 2001 Conference Proceedings

Direct Seeding in the Intermediate Rainfall Zone of Eastern Washington
Thomas G. Zwainz Reardan, Washington

Farm Profile

I currently operate three family farms. I'm fortunate to be the fourth generation to operate the Zwainz family farm, homesteaded in 1887 north of Reardan, WA. I also farm family ground owned by my mother and her siblings. These farms total 2900 acres located 20-25 miles west of Spokane, WA, in a 17-18 inch rainfall zone.

The third farm is owned by my father-in-law, located 3 miles West of Colfax, WA. in a 19 inch rainfall area. As with many of the farms in Whitman County, many of the hills exceed 40 % slope. We operate this 1100-acre farm through a family held corporation. This farm had been continuously cropped until the farm program mandated set aside acres. In 1987 when I became the farm manager, I arranged the farm into divided slope and strips to eliminate erosion.

Farm Objectives

1. Eliminate water and tillage erosion.
2. Utilize water more effectively.
3. Reduce wild oat and other weed pressures to maintain certified seed production.
4. Increase farm profits.


Both operations have their own Concord air drills with Anderson openers. The Reardan operation has a 30-foot drill on 10-inch spacing with a tow-between cart. The cart has two compartments for seed and/or dry fertilizer and a 730-gallon poly tank. The drill also can carry 280 gallons of liquid fertilizer.

The Colfax operation has a 28-foot drill on 12-inch spacing, semi-mount 110 Bu. cart, 300-gallon liquid fertilizer tank and a 525 NH3 tank mounted on the hillside hitch.

A Cat 65 Challenger with 500 gallons of liquid fertilizer pulls both drills. I have modified the Anderson openers on both drills, adding a second stainless steel liquid fertilizer tube directly behind the first tube to allow two different types of liquid fertilizers.

Motivation for change

  1. We can't continue to farm the next 100 years as we have the past 100 years.
  2. Soil erosion will not be tolerated. --Saturated soils are the main cause of erosion (i.e. summerfallow).
  3. A continuous cereal grain rotation is not financially sustainable because of disease and weed problems.

The Religion of Direct Seeding

In the fall of 1996, I accompanied six other Lincoln county farmers and Diana Roberts from Cooperative Extension, to Dr. Dwayne Beck's program at Dakota Lakes Research Station in Pierre, South Dakota. Dr. Beck recommended a four-year rotation of two cool season grasses followed by a warm season grass and then a broadleaf, would be the best rotation (i.e. spring wheat, winter wheat, corn, and broadleaf). The reasons for this rotation are as follows.

Spring wheat following the broadleaf.

  1. The problem with spring direct seeding is cool soils. Solution: Keep your lowest residue crops for spring seeding. The soil is darker, therefore the soil will warm up more quickly in the spring.
  2. The problem with continuous cool season grasses (cereal grains) is disease pressure. Solution: Sanitizing the soil by not seeding any cool season grass for two years.
  3. Another problem with back to back spring cereals is the previous crop volunteer. Solution: By having different crop families, one can control the volunteer with chemicals.

Winter wheat seeded into spring wheat.

  1. Maximum protection from cold winters is achieved from the standing spring wheat stubble.
  2. The standing stubble offers the most snow to be trapped.
  3. Volunteer grain is not a problem because it is a similar class of wheat.

Corn seeded into winter wheat stubble.

  1. Typically, the highest residue crop is winter wheat. This causes our most difficult problems in the Pacific Northwest. First, equipment has a difficult time seeding into large amounts of residue, especially in wet conditions. Second, the soil warms up much slower in the spring. Solution: Seeding later with a warm season grass like corn, when residue is dryer and using 20-30 inch spacing on the drill, allows maximum residue clearance.
  2. Volunteer winter wheat can be difficult to spray out, especially in cool, wet springs. Solution: Two applications of Round-up, either one in the late fall or early spring, to knock down the volunteer and a second application later in spring to kill any escapes from the first application, as well as new spring germination's like wild oats.

Broadleaf seeded into corn stubble.

  1. The problem, as stated earlier, of breaking disease and pest cycles is to sanitize the soil. This is achieved by not seeding cool season grasses (cereal grains) for two years.
  2. Another advantage of including a broadleaf in the rotation is the diversity of herbicides available to control weeds, like wild oats.

Back to the farm to try all this new knowledge.

Dr. Beck prescribes a minimum disturbance system to minimize weed competition, which I agree, works in South Dakota. He advised us to look at our native vegetation to determine what crops should be included in our rotations and at what frequency. With the help from Dr. Diana Roberts and Dr. Bob Gillespie, we found some virgin land next to the home farm and did the native vegetation survey. We found no native warm season grasses. Cool season grasses out numbered the broadleaf's 3 to 1. This is the basis for the rotation that I have attempted to duplicate. I have also tried dryland dwarf corn in the attempt to follow Dr. Beck's rotation. Totally following Dr. Beck's system would have lead us to buying a minimum disturbance disc type drill. There were three reasons why we chose a high disturbance drill. 1. The upper mid-west receives more rain in the summer than we receive, therefore pushing the fertilizer down into the root zone. We felt our fertilizer needed to be deeper in the profile than a disc drill could provide in the spring. 2. The new rotation relies on alternate crops that have not been proven for our region. Therefore, cereal grains would be more frequent in our rotation, exposing us to more soil borne diseases. Using Dr. Cook's research, we chose the Anderson opener to provide seedbed disturbance to reduce soil borne diseases. 3. During the transition into direct seeding, half of the farm was still going to be conventional, so a shank style drill would replace our conventional hoe opener drill.

In the spring of 1997, following the trip to South Dakota, I was able to talk my father into buying the first Concord air drill. Since that time, we have seeded the following alternative crops with the drill. Included next to each crop is my opinion of the viability of these crops at the Reardan location as well as Colfax (Colfax is located 70 miles to the South of Reardan and has a longer growing season.).

  1. Canola--good fit for both Reardan and Colfax; backed by farm program.
  2. Corn--not enough heat at Reardan; good possibility in lower area's of Colfax.
  3. Flax-- needs better variety selection; possible value added markets; backed by farm program.
  4. Lentils--need a better price for Reardan and Colfax.
  5. Mustard--need to plant early; fair results at Reardan; good results at Colfax; backed by farm program.
  6. Buckwheat--needs more heat at Reardan; have not tried at Colfax, however with the longer growing season should work well; need to contract before seeding.
  7. Safflower--needs more heat at Reardan; have not tried at Colfax, however with the longer growing season it should work well; backed by farm program.

The marketing of the alternate crops is the most difficult. I would recommend contracting the delivery of these crops before planting.

The Bottom Line

  1. Goals and objectives-- What are you trying to accomplish? Sometimes controlling erosion is very expensive. The strip cropping I did in the late 80's and early 90's was successful for erosion, but very expensive. Continuous cropping was profitable for the landlord, controlled water erosion, but was not as profitable for the tenant and caused lots of tillage erosion. Removing summer fallow from a rotation may look good on paper, but if the landlord likes bragging rights at the coffee shop, your objectives may be different. An example of this is growing 57 Bu/acre spring wheat, then direct seeding winter wheat that averaged 53 Bu/acre. Our summer fallow winter wheat averaged 80 Bu/acre. The landlord was disappointed in the fall recrop winter wheat only averaging 53 Bu/acre. They did not consider the two years of direct seeding that gave them 110 Bu/acre verses the 80 Bu/acre fallow wheat. It is a must that all partners and landlords have the same objectives. If all parties do have the same objective, then the landlords should be willing to share more of the fertilizer and chemical expenses, because they will be sharing in more crop.
  2. Rotation. -- I have tried several different rotations with different crops. The 2000 crop showed me the necessity of crop rotation. One field of winter wheat that had been in cereal grains for four years in a row (winter wheat, spring barley, spring wheat, winter wheat) was a total disaster due to Take-all, yielding only 41 Bu/acre. Conversely, the most successful field of winter wheat seeded into spring wheat averaged 77 Bu/acre. The rotation on this field had been a modification of Dr. Beck's original recommendation, using his four-year rotation and substituting barley for the corn. We have achieved all our objectives.

2001 Cropping System

The rotation that I have transitioned into on the home farm is the four year rotation, spring wheat, winter wheat, spring barley, and a broadleaf. The sequence of operations next spring should be as follows:

  1. Spray Round-up
    1. 2000 broadleaf field (1)
    2. 2000 spring barley field (2)
    3. 2000 winter wheat field(3)
  2. Seed spring wheat into 2000 broadleaf field (1)
  3. Seed spring canola (broadleaf) into 2000 spring barley field (2)
  4. Wait for first flush of wild oats to emerge, then spray 2000 winter wheat field for the second time with Round-up.(3)
  5. Spray 2001 winter wheat crop.(4)
  6. Seed spring barley into 2000 winter wheat field.(3)
  7. Go to the Spokane Jr. Livestock Show, first week of May
  8. Spray spring wheat field (1) with post-emergent oat and broadleaf herbicide.
  9. Spray spring broadleaf field (2) with post-emergent oat herbicide.
  10. Spray spring barley field (3) with post-emergent oat and broadleaf herbicide.


The combine must have a straw chopper. Distribution of the chaff and straw must be uniform. We currently fall harrow some fields because of inadequate chaff distribution. 95 percent of our drill plugging problems are a direct result of harvesting with the headers too high. Extra time taken during harvest to keep the stubble length less than 10 inches should preclude the need for harrowing and/or chopping. If you have excessively high crop residue, take care of it in the fall before spring planting. If you do not have the equipment to chop the residue, or bale and remove the straw, then work it down before spring. The only other option would be to burn, which I do not recommend.

For five of the last eight years, our spring wheat yielded more than 70 Bu/acre. Four out of those five years the spring wheat was seeded on broadleaf residue. This year the spring wheat on broadleaf residue out-yielded my spring wheat on spring barley stubble by 14 Bu/acre.

Summer fallow wheat can easily be in excess of 90 to 100 Bu/acre. Having a 60 Bu/acre spring wheat crop, followed by 60 Bu/acre fall recrop winter wheat, is much easier and cheaper to manage than the 100-bushel stubble. The last three years of spring wheat, recrop winter wheat has produced a minimum of 20 bushels and up to 45 bushels an acre more than my summer fallow winter wheat.