2008 January Direct Seed Link

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Back-to-Back Wheat Rotations What are the Risks of Root Diseases?		Cropping Systems Strategies ...................................3 North American No-till Network ............................4 Thank You Lifetime Members & Supporters ...............................5 PNDSA Membership Information .................................5 Chaff, Stubble & Residue UPDATE FROM THE PRESIDENT ...........................6 2008 Direct Seed Partners ......6
By Timothy Paulitz, USDA-ARS, Root Disease and Biological Control Research Unit, Pullman, WA
Given the recent high price of wheat ($13+/bu, Jan. 2008) and the economic returns, more and more growers will be planting wheat back-to-back. A recent economic analysis by WSU economist Kate Painter, based on Nov. 2007 prices, showed a net return of $370/acre for winter wheat in an 18’ rainfall zone, compared to $47/acre for peas. But crop rotation provides numerous benefits that should be factored into your planting decisions. One is a yield boost − studies in the late 80s showed an increase of 30 bu/acre of winter wheat after peas, compared to after winter wheat. Crop rotation provides other benefits in terms of residue management and weed management, especially the ability to rotate herbicides and control grassy weeds. But probably the biggest effect of crop rotation is to manage root diseases. By growing a crop that is not a host to a soilborne pathogen, the levels of the pathogen will be reduced in the soil. What diseases are controlled by growing a crop that the pathogen cannot attack? One is take-all, caused by the fungus Gaemannomyces graminis var. tritici. World-wide, this may be the most important root disease on wheat, but is a minor problem in our dryland production areas, both annual cropping and wheat-fallow. We know that the pathogen is present in most areas, but the disease is easily managed by a broadleaf (non-host) crop such as peas every 3rd year. Barley is also a host, but is less susceptible than wheat. This disease is favored by higher rainfall and irrigation. It causes whiteheads and a black discoloration of the roots and crowns. Over the last few years, I have seen outbreaks on continuous wheat under irrigation. It usually becomes a big problem by the 2nd to 3rd year. However, if monocrop wheat is continued long enough, the disease goes into decline (take-all decline) due to the action of antagonistic natural bacteria (Pseudomonas) that build up and suppress the disease. Depending on the location, this can take 5-7 years to attain.
In their book on wheat health management, Jim Cook and Roger Veseth said “Crop rotation is the single most critical factor affecting the health and productivity of a future wheat crop… Crop rotation is a process of soil sanitation — the action of antibiotic, predatory, and competitive organisms in the soil, old roots, and straw gradually destroys the pests and disease organisms in the soil”		Watch for new information and links on the PNDSA Website: www.directseed.org BUY/TRADE/SELL your direct seed custom services and equipment at www.directseed.org/4sale.html


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LEFT: crown of wheat with severe take-all symptoms. Note black discoloration on lower stem and crown roots. RIGHT: whiteheads caused by severe infection of the crowns with Gaeumannomyces graminis var. tritici. BELOW: Take-all on wheat, healthy plant on left; right shows plant with severe infection crown roots with take-all. Note black discoloration.
	Common root rot (Bipolaris) is another minor disease in dryland production that could become more important with continuous wheat. Other diseases that may benefit from rotation to a non-host include strawbreaker foot rot (eyespot), Cephalosporium stripe, and snow molds. These are primarily problems on winter wheat, and rotation to spring wheat could avoid these problems. A winter wheat–spring wheat rotation may be better than a continuous winter wheat rotation, since the 6 months of no crop may provide some soil sanitizing effect, and would certainly help with weed control. There is genetic resistance in some cultivars to these diseases. What about insects? Hessian fly is primarily a spring wheat problem, and survives in the crop residue. This insect, along with wireworm, can be reduced by crop rotation. There are some diseases that may not be reduced by rotation, because they have a wide host range. They not only attack wheat and barley, but also broadleaf rotation crops. This includes Pythium and Rhizoctonia.However, our recent work with molecular detection methods, indicate that certain rotations will favor particular species of Pythium or groups of Rhizoctonia, so continuous wheat may select for more virulent groups of these root-rotting pathogens. What about Fusarium crown rot, which is becoming more serious on hard red spring wheat managed for high protein? This disease is favored by water stress and high nitrogen fertilizer. It attacks wheat and barley, but not the broadleaf crops. However, it can survive for a few years in crop residue and in the soil, so a one-year rotation out of wheat may not provide much benefit. Without crop rotation, growers will have to rely on other control measures. Genetic resistance is not available for Pythium, Rhizoctonia, and Fusarium, although programs at Washington State University and Oregon State University are trying to develop this. Seed treatments have a limited effect, mainly to protect seeds and very young seedlings. This leaves cultural management methods, such greenbridge control, tillage, fallow, residue management, seed opener disturbance, time of planting, and application of starter fertilizer in the seed row. The benefits of crop rotation should be factored into any decision on planting, especially for the long-term sustainability of your cropping system.


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CROPPING SYSTEMS STRATEGIES: Add Yellow Winter Peas to Rotation By Howard Nelson, Manager of Member/Special Services, Central Washington Grain Growers, Inc. Yellow winter peas are a new crop giving growers an opportunity to grow something different than winter wheat in the intermediate to low rainfall areas of Washington. Studies have shown that spring peas in a rotation with wheat will boost the yields of following wheat crops in the intermediate and high rainfall areas. This increase is caused either by decreased disease levels in winter wheat or by an increase in nitrogen (N) levels experienced following legume production. A trial was designed to test this rotational benefit in winter wheat following winter peas in the low rainfall area of Eastern Washington. The trial was planted in a 320 acre field that was split into 80 acres of winter peas and 240 acres of winter wheat in 2005. The area for this trial was then chem-fallowed during the summer of 2006 and planted that fall using a small plot direct seed drill equipped with Anderson type openers. This field was located in an 11-inch rainfall area near Wilbur, WA. Soil tests were taken from the winter pea and the winter wheat sites in March of 2007. They showed very high levels of residual N differences between the two rotations (See table at the right). These differences required that the trial include a N rate study to see if this was causing the difference in yields. Nitrogen was applied at rates of 5, 45, 85, 125, 165 and 205 lbs/acre. Each plot also received 20 lb/ac of phosphate fertilizer. Sulfur was mixed with the nitrogen fertilizer at the ratio of 5 lbs N to 1 lb S. In addition to the six different N rates, five different varieties of hard winter wheat and one winter triticale variety were planted in a replicated randomized block design. The varieties of wheat planted were: Paladin, Eddy, Bauermiester, MDM and WA 7976. The triticale variety planted was TriMark® 336. These varieties came from four different breeding programs and are Resource Seeds, WSU, Westbred Seed Co. and AgriPro. Two identical trials were planted side by side, one following winter peas and one following winter wheat. The pictures show the plots planted to Bauermeister winter wheat in the 85 lb N/acre treatment. The winter wheat rotation is on the left and the winter pea rotation is on the right. There was a visible difference between the two rotations with the winter wheat following winter peas being noticeably thicker and was on average 4 inches taller than the winter wheat rotation. The results from these trials are a little unusual because the 5 lb N/acre treatment had the highest wheat yield. This was due to the high levels of residual N at this location. This trial had a highly significant yield increase in the winter pea rotation for both triticale and wheat. The triticale yield curve for applied N is shown in Figure 1 and the yield curve by N supply is shown in Figure 2. On average across the N treatments, the triticale yield increased 1,542 lbs/acre or 29.8% following winter peas. (Average winter pea rotation yield of 6,714 lbs/acre and average winter wheat rotation yield of 5,172 lbs/acre). The winter wheat yield curve for applied N is shown in Figure 3 and the yield curve for N supply is shown in Figure 4. Winter wheat yields on average across the N treatments increased 37.0 bu/acre or 67.2% following winter peas. (Average winter pea rotation yield of 92.1 bu/acre and average winter wheat rotation yield of 55.1 bu/acre). This trial has raised several questions. There was only a slight difference in the stored soil moisture of the two rotations with the winter pea rotation having 1.07 inch more. According to work done by Bill Schillinger of WSU, the 1.07 inch increase of stored soil moisture would account for 6.0 bu/acre of the increase of the winter pea rotation. Second, there was no yield response to the differences in N fertility, but here was a significant response in grain protein to the N treatments (data not shown). It appears that we are seeing a true rotational benefit following winter peas. We can only speculate what is causing that benefit. The yield decline could be caused by sub-clinical levels of disease in the soil or disease complexes that are holding back wheat yields. There is research from Canada indicating that the rotational benefit could be caused by an association between the Rhizobium bacteria, used to inoculate the peas, and the wheat roots. These bacteria have been found in the wheat roots, and this relationship could improve plant nutrition or reduce root disease in these plants. It also appears that winter triticale has more tolerance than winter wheat to the agent that is causing the yield decline. Average triticale yields following winter peas increased 29.8% as compared to the 67.2% increase of winter wheat. Stating this a different way, if the yield decline for triticale in the winter wheat rotation is 1.0 x, then the yield decline for winter wheat in the winter wheat rotation would be 2.3 x. The data from this rotation study is from one year and we plan to repeat it a second time. You can view the complete results of this trial by accessing the Newsletter section of our web site, www.cwgg.net, and view the 2007 Test Plot Results. This file has the complete dataset and shows the statistical analysis of this data.		ABOVE:Winter Wheat on Winter Wheat Rotation BELOW: Winter Wheat on Winter Pea Rotation

After a short presentation by each group it was clear there was much to be gained by this type of interaction. While each group operates differently and in different agro-climatic regions there are many common issues between them. From organization financing to extension programming we are dealing with many of the same issues. The members of CASA will be a great resource for everyone involved and as involvement grows so will the reach and effectiveness of delivering the direct seed/no-till message. Interacting with other organizations that exist at different levels of adoption rates also provides an opportunity to evaluate individual direct seed programs to determine if they are on track with other regions. A few of the similarities that came across at the Georgia meeting include: the annual conferences draw similar numbers; membership remains consistent between regions; funding sources and partners treat each region relatively equal. Another priority of CASA will be to develop a consistent message for industry to use when discussing conservation agriculture issues. This is important between agro-climatic regions, government departments, education and research institutions, industry and also internationally. It is anticipated that CASA will be developed to represent NA no-till interests on the international stage and will strive to be recognized by the United Nations FAO in the same light as the SA group (CAPPAS) and European Conservation Agriculture Federation.
The CASA organizers have put in a request to the CTIC Board to have CTIC act as parent organization for up to 24 months to help incubate the organization through its initial start up. If you would like more information or want to discuss this development go to www.directseed.org/links.html follow the links through to the CTIC webpage: Learning Center: CASA: Discussion forum.

How I make a Direct Seed Cropping System Work
Thursday, February 7, 2008 - 7:30 a.m. to 10:00 a.m.
$15 fee includes Breakfast and Spokane Ag Expo Admission

   During Spokane Ag Expo 2008, the Pacific Northwest Direct Seed Association and Spokane County Conservation District will host a breakfast panel “How I Make a Direct Seed Cropping System Work” in Seminar Rooms 206B&C in the newly completed Spokane Convention Center Complex.
     The Spokane Ag Expo Direct Seed Breakfast will deliver practical information from successful growers delivered to growers making the change to a direct seed system. In addition to a four grower member panel presenting information from different farm sizes, rainfall regions and agro-climatic zones, the seminar will also host, from New Zealand, Dr. John Baker, CEO of Baker No-Till Systems. Dr. Baker brings a wealth of research and scientific documentation that support the well established principles of direct seed cropping systems.
     The meeting will be moderated by Washington-Idaho Conservation Tillage Extension Specialist Dr. Hans Kok. Bring your questions for an extensive Q & A session following the panel presentations.
     Make your reservations now for Thursday, February 7, 2008 to come for breakfast, learn from leaders in your community and stay the whole day to explore the benefits of direct seed at the Spokane Ag Expo. The $15.00 fee includes breakfast, Spokane Ag Expo admission and free parking at the Arena with shuttle service to the breakfast.
     To reserve a guaranteed seat for the Direct Seed Breakfast Meeting, mail your $15 per person payment to: Spokane County Conservation District, 210 N. Havana, Spokane, WA 99202 by February 1, 2008. Seating is limited, please book early to avoid disappointment. If you need more information please contact PNDSA@directseed.org or 208-883-3645.

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    As president of the PNDSA, I have always been very careful to recognize the chronically precarious position farmers live in. It would be entirely too simplistic to say farmers must always address conservation at the expense of all else. While such a statement would be true regarding the long term survival of the land and thus the farmer, it would ignore the short term reality of the farmer’s economic plight. With few exceptions during the last thirty years, farmers have found very little room to trade financial gain for conservation benefit. If this observation sounds familiar, it should. I have shared it before and any farmer that does not live in a permanent fog already is well aware of this stark reality.
     So why am I bringing it up once again? This newsletter article will be my last as president of the PNDSA. You may hear from me again regarding an issue or two, but not as the author of the president’s message. I probably should simply say thanks for trusting me to lead your association and step off the soap box, but I feel too strongly about Direct Seeding, PNDSA, and the PNDSA members to bow out without one last effort to tell you what a great experience this whole effort has been.
     I can honestly say I have never served any organization that I was more proud of. Some of my agricultural industry responsibilities prior to becoming part of the PNDSA required me to focus on limited issues within the bigger picture of agriculture. These issues were important, but they required focused attention and the ability to minimize or ignore the negative trade-offs that always accompanied the effort.
     With Direct Seeding I see a tremendous list of winners across the board. Direct Seed farmers can dramatically lower costs and time invested into a crop while all but eliminating exposure to erosion and turn from a carbon emitter to becoming a carbon bank. The general public receives dramatic savings in reduced sedimentation of road ditches and waterways as well as cleaner air and wildlife habitat. Broad public and political support for environmental benefits positions agriculture for legislative support through conservation programs, and make no mistake, Direct Seeding is the Cadillac of conservation efforts. I tip my hat to those of you that have chosen to be leaders in the transitioning of agriculture to Direct Seed by adopting Direct Seed systems, and I thank you for becoming PNDSA members.
     In closing, I want to thank past and present board members, partners, prior PNDSA presidents, the University of Idaho, Oregon State University, Washington State University, and PNDSA staff for their support, time, and money. We would not be here today without all of you.