|
|
|
|
|
|
|
||
|
|
||
|
|||
2000 STEEP III Annual Progress ReportPROJECT TITLE: Integrated conservation spring cropping systems for the arid and semiarid wheat-fallow region of the PNW. 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, Whitman Co. Grain Growers, and 12-member grower group from low and intermediate rainfall zones. PROJECT OBJECTIVES:
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 no-till spring
cropping project for the wheat-fallow region has completed Phase I (5
yrs.) of this study. Planting of this year's winter wheat initiated Phase
II, which entails continuing with Phase I (some systems have been changed),
establishing four additional cropping systems for Phase II, and investigating
single component research interests via satellite studies. Post-harvest
data collection for soil fertility, soil moisture, soil quality, weed
seeds in the soil, weed populations, insects, and diseases have been completed.
Final analyses will be conducted this winter. Crop yields were higher
in 2000 than in 1999. Most noticeable was in winter wheat and spring barley.
No-till hard red spring wheat made protein regardless of crop rotation.
It appears that Russian thistle, Hessian fly, and Rhizoctonia root rot
are the major pests encountered in continuous no-till spring cereals.
In early June, scientists and growers hosted a field day that focused
on agronomically successful crop rotations. RESULTS AND INTERPRETATION:
The 1999-2000 crop year concluded the 5-yr Phase I study of the Ralston Project. This harvest year also concluded a complete crop rotation cycle in which 'Scarlet' hard red spring wheat and 'Rely' club winter wheat were planted. For the fifth consecutive year, satellite studies were conducted to evaluate new sprayer technology for reduced pesticide use for Russian thistle control, manipulation of crop planting dates for Russian thistle suppression, and seeding rate study. Objective 1. Residue management, straw decomposition, and soil cloddiness: Knowledge of various cereal cultivars and alternative crops will permit the inclusion of varieties with specific decomposition rates in the crop rotation as a means of maintaining residues at desired levels. Straw decomposition rates of cereal cultivars vary and little is known about cultivar decomposition rates for the Pacific Northwest (PNW). Cereal cultivars vary in their fiber, C, N, and S content and the parameters of total N, lignin, hemicellulose. C:N ratio are good indicators of decomposition rate. Decomposition potential varies with tillage intensity, location, and years. Differences in soil quality analyses have emerged with alternative cropping systems, but there are no clear trends to indicate advantages for any treatments tested. Soil microbial populations and communities are changing but it is not known if this is a positive response. Objective 2. Quantify
pest incidence in no-till spring cropping systems and the traditional
winter-wheat fallow: No-till annual spring wheat. Two diseases were of continual importance in no-till annual spring wheat. Until year 5, the incidence (percentage of infected plants) of both Rhizoctonia root rot and take-all had always been highest in the experimental section lying east of Marcellus Road, and lowest in the section located west of Marcellus Road. It was assumed that this difference, due to plot location, was associated with the cropping history for these fields before the experiment was established. The eastside had four cereal crops during the 5 years preceding this experiment whereas one cereal crop was grown on the west side. Although disease incidence was always higher on the east side, this difference from crop history was not always apparent for disease severity ratings. During 1999, the amount of root cortex disintegration, supposedly due to root lesion nematode, was also higher on the east than on the west side of the experiment. No-till spring wheat/ spring barley. Spring wheat and spring barley were swapped back and forth between the west side and east side plots during consecutive years. A distinct positional effect occurred for Rhizoctonia root rot during years two, three, four, and five. In spring barley, 95% of the plants or tillers were infected with Rhizoctonia root rot with a disease severity rating of 2.4 (on a scale of 4.0) in 2000. Patches of depressed plant growth and grain yield were not as prevalent as in 1999. Disease was more severe on the east side than the west side, regardless of whether wheat or barley was planted. Damage from this disease is usually more severe on barley than wheat. The positional effect for plots in this experiment was, therefore, more important than genetic susceptibility of the crop species. This presumptive observation was based on differences in crop history before the experiment began. During year four, take-all was more severe on the east than west side, but the pattern of prevalence was reversed during year five. During the last 2 years, the prevalence of take-all has been higher on spring wheat than spring barley. This pattern has indicated that differential susceptibilities of these plant species have become more important than field history at this stage in the maturation of this continuous no-till annual cereal rotation. There were no aphids (English, Russian, etc.) detected in winter wheat. In spring cereals, aphid populations exceeded 1998-99 levels but remained below economic levels. Aphid densities peaked at early dough development, with English grain aphid (EGA) ranging from 5.5 to 7.5% infested tillers and Russian wheat aphid (RWA) densities from 0.5 to 1.25% infested tillers. Spring barley supported no EGA and few RWA (0.5% infested tillers). There were moderate numbers of Coccinellid predators detected in spring wheat, with highest populations on July 7. A substantial number of parasitized aphids (8 to 29%) also were found in spring wheat on this date. Fifteen to 47% of winter wheat and spring wheat tillers, respectively, were infested with Hessian fly (HF) larvae and puparia. The economic injury level was "estimated" to be 15 to 20% infested tillers. 'Baronesse' spring barley was resistant to HF attack. HF mortality between egg and larvae/puparia stages in spring wheat and spring barley ranged from 85 to 97%. The number of HF infested tillers has increased dramatically over the last three seasons with the highest populations consistently detected in continuous hard red spring wheat. Infestations in hard red spring wheat in rotation with barley exceeded the economic injury level in 2000, although levels were considerably lower than in continuous hard red spring wheat. Infestation levels in winter wheat were extremely low prior to 2000 but reached 23% infested tillers in 2000. This may reflect the natural phenomenon of year-to-year variability in populations of pest insects, or the close proximity of winter wheat to no-till spring wheat plots and competition from host plants. Results from this 5-yr study and satellite studies indicate that the deployment of HF-resistant genes in wheat cultivars can prevent economic losses. Russian thistle is still the primary weed in spring cereals. As in 1999, a post-harvest herbicide application was not applied to spring barley or hard red spring wheat plots. In-crop herbicides for the control of Russian thistle were rotated for the fifth consecutive year to prevent herbicide resistance to the sulfonylurea herbicides. After 5 years, no other major weed species shift has occurred in the continuous no-till spring cereals. A very heavy population of downy brome infested the winter wheat plot on the west side in 2000. Maverick herbicide was applied in late February/early March and controlled about 50% of the population. The application suppressed the downy brome for the remainder of the growing season and reduced greatly the weed seed production. The winter wheat stubble will be disked lightly incorporating weed seed into the soil to initiate downy brome germination this fall/winter. Objective 3. Cropping systems profitability and risk: The purpose of the economic analysis of the Ralston Project is to assess the profitability of no-till cropping systems in comparison to the traditional winter wheat-fallow system. In the case of this study, the winter wheat-fallow system entails a conservation tillage regime that does not include severe fall tillage with several subsequent rodweedings in the summer. Economic analysis of the first 5-year data set has been conducted. Average net returns over total costs are negative for all four cropping systems for the period 1996-2000. Grain farmers have received substantial government payments from 1998-2000 but they were not figured into the Ralston profitability results. The traditional winter wheat/fallow system dominated the 1996-2000 average profitability. Winter wheat after fallow has yielded exceptionally well for the region averaging 69bu/ac (5-yr average). Relatively low production costs of the wheat/fallow system contributed to its profit advantage. When comparing net returns over total costs (best long-run measure of profitability) the spring wheat/chemical fallow system ranked second, followed by no-till hard red spring wheat/spring barley, and the least profitable was the continuous no-till hard red spring wheat. This system was ranked last because of the higher fixed costs as well as the declining price premium for protein in hard red spring wheat (1995 to 1999 compared to 1993 to 1997). It is quite possible that growers may be able to trim the cost of hard red spring wheat production by further reducing fertility and herbicide costs. Additional research has indicated the public values higher levels of air quality which continuous cropping systems provide. The public may be willing to cost share for growers to profitably adopt soil conserving annual spring cropping systems. Crop yields for the 1999-00 growing season (Table1) were slightly higher compared to the yield in 1999. Table 1. Crop yields
for the 1999-00 spring cropping project at Ralston, WA. Winter wheat yielded 66 bu/a, 11 bu/a higher than the long-term average of the experimental site. This included competition from a light-to-moderate stand of downy brome. Because soil moisture was plentiful in the spring of 2000, additional nitrogen was applied (15 to 20 lbs./a) to the winter wheat. Alpowa spring wheat no-tilled into chem fallow stubble (18 mo. fallow) yielded 45 bu/a. A third treatment of soft white wheat compared facultative spring wheat (Alpowa) planted in November of 1999. This treatment yielded 57 bu/a. Continuous no-till hard red spring wheat yielded an average 30 bu/a with protein nearly 15.5%. Interestingly, the no-till hard red spring wheat following spring barley yielded 35 bu/a with a 14.2% protein. Researchers speculate that the 5 bu yield increase compared to continuous hard red spring wheat was because of a 15 to 20% reduction in HF infestation in the wheat/barley rotation compared to continuous wheat. No-till spring barley was 20% higher in 2000 than in 1999. Barley was also located on the east side of the road where Rhizoctonia incidence is highest. Objective 4. Accelerate grower evaluation and adaptation of profitable conservation farming systems and conduct field days and presentations to disseminate information: A few growers continue to evaluate portions of the main plots, satellite studies, and alternative crops on their farms. Ideas, concepts, and practices from this study are often included in other studies initiated throughout the PNW. A discussion of publications, field days, etc. are included in the last section of this report. STEEP III is one of the major funding agencies for this project along with the Washington Wheat Commission and the PM10 /CSREES. 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 to be told-either verbally or written. 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: In early June, a large field day was held at the Ralston site. Over 170 growers, researchers, and field consultants attended. The agronomically successful cropping systems of continuous no-till hard red spring wheat and no-till wheat/barley were compared to the conventional wheat-fallow system. Comparisons included topics of economics, soil moisture, weed management, and fertility. Other areas of discussion included spring wheat varieties, herbicide resistant weeds and crops, and cropping systems for Phase II. Presentations and proceedings include: (a.) 59th Annual Pacific Northwest Insect Management Conference, January 2000, Portland, OR; (b.) Field day proceedings included in the 2000 Ralston Project/Washington State University Technical Report. Topics included economics, nutrient cycling, and crop yield, (c.) several county agent, wheat grower, and agribusiness meetings as guest speaker, and (d.) American Society of Agronomy Conference, November 2000, Minneapolis, MN |
||||
 Contact
us: Hans Kok, (208)885-5971
|
Accessibility | Copyright
| Policies | WebStats | STEEP Acknowledgement |
||||
