1998 Table of Contents

1998 STEEP III Progress Report

INVESTIGATORS: Frank Young, USDA-ARS agronomy and weed science; Kim Kidwell, WSU spring wheat breeding and genetics; and Bill Pan, WSU soil fertility and crop residue.

COOPERATORS: Rich Alldredge, WSU agricultural statistics; John Burns, WSU extension; Steve Clement, USDA-ARS entomology; Curtis Hennings, grower; Ann Kennedy, USDA-ARS soil microbiology/residue decomposition; Bill Schillinger, WSU soil moisture and extension; Dick Smiley, OSU plant pathology; Steve Ullrich, WSU barley breeding and genetics; Roger Veseth, U of I/WSU extension and tillage; Joe Yenish, WSU weed science and extension; Doug Young, WSU agricultural economics and Larry McGrew, USDA-ARS technician.

OTHERS: Monsanto Agrichemicals, McGregor Company, Connell Grain Growers, and 12-member grower group from low and intermediate rainfall zones.

PROJECT OBJECTIVES:

1. Determine residue management, straw decomposition rates, and soil cloddiness for the four cropping systems.
2. Quantify the incidence and impact of weeds, diseases, and insects in the no-till spring cropping systems and compare to traditional winter-wheat fallow.
3. Use standard crop production budgets to estimate the cost of production for each cropping system and rank each system by average profitability and income stability (risk).
4. Accelerate grower evaluation and adaptation of profitable conservation farming systems and conduct field days and presentations to disseminate information.

KEY WORDS: no-till cropping systems, weed population dynamics, chem fallow, wheat.

STATEMENT OF PROBLEM: The major farming practice in the arid and semiarid regions of the PNW is a winter wheat-fallow rotation. This system is characterized by soil erosion, reduced soil quality, high incidence of winter annual grass weeds and diseases. It is thought that continuous no-till spring cropping of cereals will reduce the number of fallow fields, increase residue cover on fields in the summer and fall, increase soil quality, and reduce the potential of wind blown dust. However, there are no current established best management practices for continuous, no-till spring cropping systems. Little information is known on nutrient management strategies, crop varieties, crop planting date and rate, and pest problems associated with dryland spring cropping systems. Weed species shifts and dynamics must be evaluated in these new systems.

ZONE OF INTEREST: Arid and semiarid region (low and intermediate rainfall) of the PNW.

ABSTRACT OF RESEARCH FINDINGS: The integrated, no-till spring cropping project for the wheat-fallow region has competed three years of harvest. This time period includes the set-up year as well as the conclusion of one crop rotation cycle. The planting of this year=s winter wheat initiated the second crop rotation cycle. This year, precipitation was about 1-1/2 inches above normal, however, crops (especially winter wheat) were beginning to be water-stressed in mid-May. Precipitation was 2 to 4 inches less than the previous 2 yrs. Surface residue cover and soil cloddiness measurements were concluded for the project. As anticipated the residue and crop cover in the conventional winter wheat-fallow system is much more cyclical, while the cover in the no-till continuous spring crops is maintained throughout the season. Crop yields were excellent this year despite the fact that downy brome was severe in winter wheat and Rhizoctonia was damaging in spring crops. No-till hard red spring wheat (HRSW) made protein regardless of crop rotation. This, in turn, made HRSW systems almost as economically feasible as the traditional winter-wheat fallow system. In early June, almost 200 growers, researchers, agribusiness people, and academic administrators attended an all-day field day.

RESULTS AND INTERPRETATION: The 1997-98 crop year marked the completion of one crop rotation cycle in which all appropriate treatments were established. Annual precipitation was slightly above the normal 11 inches but was 4 to 5 inches below last year=s rainfall. During this past year, several satellite studies were continued, expanded, or initiated. Alternative crops evaluated included buckwheat, millet, and intercropping with oats and peas.

Objective 1. Residue management, straw decomposition, and soil cloddiness: Residue management appears to be greatest in the early years after adopting no-till technologies, and this problem decreases as the land is continually no-tilled. The biological factors controlling this Atransition period@ need to be investigated to assist growers in developing appropriate management strategies for the Aestablishment years@ of no-till. Knowledge of residue decomposition of various crop species will aid growers in designing crop rotations to fit specific no-till needs. Samples for soil quality analysis and residue decomposition have been collected annually in the spring and fall since 1996. Laboratory incubation studies are being conducted where straw is incorporated in moist soil or placed on the surface of moist soil (no-till) and decomposition rate monitored over 16 weeks. Also new techniques are being developed to analyze for residue decomposition in the field and laboratory.

Microbial activity varied by treatment with continuous spring wheat having the highest levels compared to spring wheat/barley or the fallow systems. Results from several other soil quality analyses varied with the season (time of year). A greater length of study time is required to determine all the soil quality benefits which will occur if these practices are adopted long-term. As expected, cereal cultivars vary in their decomposition rate and this rate varies with location and year.

Surface cover (residue and green crop) and soil cloddiness has been measured for 3 yrs and thus concludes this portion of the study. At the present time data from 1998 have not been compiled and analyzed; however, a peer-reviewed journal manuscript is being prepared. For both fallow systems (traditional winter wheat and no-till spring wheat) crop residue was highest during the winter following wheat harvest (>90%). Winter wheat residue was reduced almost 50% after the land was disked, undercut, and fertilized. One subsequent rodweeding did not further decrease surface cover (>40%), but by the end of August of the fallow seasons, surface cover dropped to 20%. In contrast, surface crop residue in chemical fallow following spring wheat was maintained at 57%. The continuous cereal rotations behaved similarly. As an example, in the continuous no-till hard red spring wheat system spring wheat residue in March covered 70% of the ground. By late May, residue had decomposed to 32%; however, green plants (present crop) added 28% cover to the system. By harvest, 70% residue cover was agin achieved.

Objective 2. Quantify pest incidence in no-till spring cropping systems and the traditional winter-wheat fallow: For the past three growing seasons plant diseases have been quantified and evaluated for the four cropping systems at Ralston, WA. Extensive discussion on pathology is published in Dr. Dick Smiley's, STEEP III report and therefore will only be briefly mentioned in this report.

As in 1997, damage from Rhizoctonia root rot was present on winter wheat seedlings during February. Disease incidence was high (>90% of the plants affected) and severity was moderate to high (ratings of 3 on a 5-point scale). Severity ratings of this magnitude indicate significant rotting of main root axes; i.e., Aroot pruning@. Other diseases were not important during the sampling in February. Plants were 20-inches high when assessed on May 4. Damage from Rhizoctonia root rot was readily apparent in May, as evidenced by patches of stunted plants; the Abare patch@ phase of this disease. Subcrown internode lesions caused by Fusarium foot rot were also present on 35% of the plants, and was considered significantly damaging (lesions severity of 2-3 on a 4-point scale). Strawbreaker foot rot occurred on 9% of the tillers (29%) of the plants) and physiological leaf spot was present on foliage of most plants. Take-all was identified on 0- to 15% of the plants in the four replicates, but the severity of infection was considered very minor and the presence of take-all was unlikely to have an impact on yield. Stem darkening and varying levels of stem maceration on 2% of tillers was tentatively attributed to an atypical expression of Rhizoctonia disease (R. solani AG-8).

Pythium root rot and root lesion nematodes are pruning branch roots from the main root axes of seminal roots on both spring barley and wheat. Nematode damage has been observed on up to 25% of the plants in some treatments but, due to previous crop rotations by the grower , it is unclear whether there are significant differences among treatments. Fusarium foot rot has been barely detectable on the spring crops at this location. It was noted also that neither take-all nor rhizoctonia root rot were significantly more damaging in the continuous spring wheat monoculture than in the spring wheat/chemical fallow rotation.

Rhizoctonia root rot and take-all were the most important diseases of spring wheat on May 4. Although specific details of disease incidence and severity are important for these plots, it was clear that irregularities were beginning to appear in the occurrences of diseases on specific treatments during the course of this experiment (three years). One of the major discoveries on this project revealed the extreme importance of crop rotation on disease incidence. On this project, reversals of disease incidence was occurring within comparable cropping rotations and sequences depending on the location of crop (east or west field). It has been shown generally that root damage by Rhizoctonia is most severe in no-till spring barley. This was true in 1996 and 1998 when barley was grown on the east field. However, in 1997 root damage was least where spring barley followed hard red spring wheat (west field). In 1997, root damage was greatest in hard red spring wheat following spring barely (east field). 1997 was opposite of what was expected. Examination of these disease observations by the cooperating agronomist, pathologist, and grower (Young, Smiley, and Hennings) revealed that the two fields do not have comparable management. Grower history indicated that during the five yrs prior to our study, cereals were produced four of those years on the east field and only once on the west field. The rotation on the west field included three fallows and one broadleaf crop in addition to the one cereal crop grown.

In 1998 plots were surveyed extensively for aphids (Russian wheat aphids B RWA and English grain aphids B EGA) and their natural enemies on five dates. On May 18 and June 8 treatments were sampled for Hessian fly incidence. Three yrs of data illustrate the phenomenon of high year-to-year variability in the occurrence and population densities of RWA and EGA in central WA. For example, RWA populations reached economic levels in some plots in 1996 and an insecticide application was required. In contrast, RWA was almost non-existent in 1997 and very low densities were present in 1998. EGA populations were relatively high in 1996 and 1997 but very low in 1998. Some producers would likely have used an insecticide to control EGA populations however, the recommendation was made not to spray in 1997 because high populations of aphid predators were recorded. Coccinellid (lady bug beetles) densities were high in late June and early July 1998. This period coincided with high EGA activity and grain development. The high aphid predator (Coccinellid) densities kept the EGA populations in check and the canola fields located on the Hennings farm were a likely source of the predators.

Hessian flies were not found in 18 surveyed wheat fields in Adams Co. in 1977-1981. However, high numbers were detected in spring wheat plots in 1998 at the Ralston Project. At the present time, there is no research data on the relationship between Hessian fly densities and economic losses in PNW winter and spring wheat. General literature indicates economics losses with 15-20% infested tillers. In some Ralston plots, infested plants approached 35% but levels of infested tillers were low. Most infested tillers supported one fly.

Downy brome was the major weed species infesting winter wheat at Ralston as well as grower fields throughout the low and intermediate rainfall zones. Thousands of acres of winter wheat were torn up (or should have been) and replanted to winter or spring wheat. Downy brome was a problem at Ralston this year because after the 1996 winter wheat harvest, the decision was made not to disk the wheat/downy brome stubble because of the fairly low weed population. The downy brome seed, because of poor seed/soil contact, did not germinate in the fall of 1996/spring of 1997. This seed then broke dormancy, germinated, and emerged in the following winter wheat crop (1997-98). Because of this situation, a split (fall/spring) application of metribuzin (Lexone/Sencor) was made to the growing crop and postharvest disking was done to initiate germination after this year=s harvest. Because of the extremely dry fall at Ralston, very little downy brome germinated even though plots were disked.

Russian thistle was again the major weed problem in spring crops. Herbicides used to control this weed have been rotated to prevent herbicide resistance from developing. Along with an in-crop application of herbicides, a postharvest application was made in spring crops. Because of the frequent rains during early/mid summer, Russian thistle was controlled in the chemical-fallow treatment by an application of Landmaster in late July.

Objective 3. Cropping systems profitability and risk: Economic analysis will occur in 1999- 2001 at the end of the experiment. However, for each year crop yield, protein, and all production costs will be recorded. At the end of the study crop production systems will be ranked both by average profitability and risk. This past year we have also begun to examine the Atransitional economics@ for this long-term project. Rather than analyzing profit/risk only at the end of the study, we will do it for every year to determine the economic patterns required to go from the traditional farming system to the more environmentally friendly no-till spring cropping system. In addition, various economic analyses will be conducted for hard red spring wheat production. For example what are the HRSW input/returns for 50 bu, 13.4% protein compared to 38 bu, 14.5% protein? Maybe we do not always have to reach protein if yield is relatively high.

Crop yields for the 1997-98 growing season were very good (Table 1). Even with a moderate

Table 1. Crop yields for the 1997-98 spring cropping project at Ralston, WA.

WW = winter wheat; SW = soft white spring wheat; HRSW = hard red spring wheat; SB = spring barley. Yield expressed at 0% moisture, 0% debris.

population of downy brome, >Lewjain= winter wheat yielded 68 bu/A with a test weight >60 lbs. Yield may have been limited by an apparent loss of N. By wheat anthesis, a diagnostic survey revealed low N concentration in the leaves and virtually no available N remaining in the 6 ft profile. >Alpowa= spring wheat no-tilled into standing chem fallow stubble yielded 58 bu/A which was an increase of 3 bu/A compared to 1997. In 1998, continuous no-till HRSW yielded 37 bu/A (13 less than in 1997) but protein content was 15.7%, an increase of over 2% compared to the protein in 1997. However, one does not receive extra premium for any percentage over 15%. The no-till HRSW alternating with barley yielded very well (40 bu/A) in 1998 and also Amade@ protein at 14.4%. No-till spring barley yielded 1.51 T/A even though it had the highest incidence of Rhizoctonia compared to other treatments. Yield improved compared to the barley yield in 1996, the last time barley was planted in these same plots (east field). The pathogen effect on yield was lessened in 1998 because of improved management practices. These practices included increased seed rate form 55 to 65 lbs/A, increased N from 40 to 50 lbs/A, and increased P₂O₅ from 30 to 40 lbs/A.

This year, in the seeding rate study, no-till Alpowa planted at 65, 90, 115, and 140 lbs/A all yielded approximately 47 bu/A with test weights at 61 lbs/A. These results are different than last year=s results where yield increased with each increase in seeding rate. However, this year=s seeding date was 3 wks earlier than last year=s date.

Buckwheat and millet were two warm season alternative crops planted no-till in 1998. Heat and disease virtually wiped out the yield of buckwheat whereas millet performed very well agronomically. Researchers will study millet in the future as a competitive crop against Russian thistle.

Objective 4. Accelerate grower evaluation and adaptation of profitable conservation farming systems and conduct field days and presentations to disseminate information: Several growers are initiating small projects on their farms that were evaluated in satellite studies, flex crop trials, or the main plots. Growers are experimenting with spring cereal seeding rate and date and growing alternative crops such as safflower and spring oats. This past season two growers planted over 500 acres of spring oats because of this crop=s performance in our study. Numerous growers are inquiring about converting their wheat-fallow system to continuous no-till spring cropping systems. The most rewarding experience was when a few growers requested to be active in the Adecision making process@ for the project as well as have satellite studies on their farms.

Discussion of publications, field days, etc. are included in the last section of this report.

STEEP III is one of three major funding agencies for this project with the Washington Wheat Commission and the PM₁₀/CSREES being the other two agencies. Our research team has specific different, albeit overlapping, objectives for each funding agency.

This report has included additional information over and above that required in the stated objectives. On the other hand, we still have not included additional information on research areas such as nutrient management and cycling, annual spring cropping trials, winter wheat variety trials, cropping systems water use efficiency, weed biology and ecology, equipment technology, and facultative spring wheat performance. Thanks to 14 cooperating scientists a wonderfully complete picture (information) is being developed for Best Management Practices for no-till crop production in the arid and semiarid regions of the PNW. As time progresses, it will take longer and longer for the cropping system story to be told B either verbally or written.

INTERACTION (COOPERATION) WITH OTHER SCIENTISTS CONDUCTING RELATED ACTIVITY: Scientists on this project routinely interact with University and ARS researchers from ID, WA, and OR. This interaction included single component research as well as multi-interdisciplinary projects. These projects include cropping systems research in the low, intermediate, and high rainfall areas of WA as well as OR.

PUBLICATIONS AND PRESENTATIONS: On June 4, a field day was held at the Ralston site which was attended by almost 200 growers, agribusiness personnel, researchers, and college administrators. An overview of the project and economic analysis was presented. The people then walked to field sites and listened/discussed topics of research from eight scientists on pest management, water use efficiency, fertility management and cycling, crop varieties, and residue management. Several smaller, personally requested tours were conducted during the season. Presentations and proceedings include: a) 57th Annual Pacific Northwest Insect Management Conference; January, 1998, Portland, OR; b) 1st Pacific Northwest Direct Drill Conference, January, 1998, Tri-Cities, WA; c) Annual CSREES, PM₁₀ Review, February, 1998, Pullman, WA; d) Numerous county agent, wheat growers, and agribusiness meetings as guest speaker.

Contact us: Hans Kok, (208)885-5971 | Accessibility | Copyright | Policies | WebStats | STEEP Acknowledgement
Hans Kok, WSU/UI Extension Conservation Tillage Specialist, UI Ag Science 231, PO Box 442339, Moscow, ID 83844 USA Redesigned by Leila Styer, CAHE Computer Resource Unit; Maintained by Debbie Marsh, Dept. of Crop & Soil Sciences, WSU