1998 Table of Contents

1998 STEEP III Progress Report

RESEARCH PROJECT TITLE: Alternative Crop Rotations Using No-Till in Low-Rainfall Dryland Areas.

INVESTIGATORS:

• William Schillinger (PI), WSU Dryland Research Agronomist, Lind, WA
• Ron Jirava, Grower, Ritzville, WA
• Brad Wetli, Grower, Mansfield, WA
• R. James Cook, WSU Plant Pathologist, Pullman, WA
• Keith Saxton, USDA-ARS Hydrologist, Pullman, WA
• Robert Papendick, WSU Soil Scientist, Pullman, WA
• Harry Schafer, WSU Agricultural Research Technician, Ritzville, WA
• Doug Young, WSU Agricultural Economist, Pullman, WA
• Robert Gillespie, Entomologist, Wenatchee Valley College, Wenatchee, WA
• Ann Kennedy, USDA-ARS Soil Microbiologist, Pullman, WA
• Chad Shelton, Agronomist, Western Farm Service, Spokane, WA
• Joe Yenish, WSU Extension Weed Scientist, Pullman, WA
• Tom Lumpkin, WSU Alternative Crops, Pullman, WA
• Roger Veseth, WSU/UI Ext. Conservation Tillage Specialist, Moscow, ID
• Bruce Sauer, WSU Farm Manager, Lind, WA

DURATION: Second of three years

OBJECTIVES: To determine the long-term feasibility of diverse, no-till annual cropping systems for low-rainfall dryland areas of the inland Pacific Northwest. Specific objectives are:

1. Develop long-term rotations which include alternative crops such as yellow mustard and safflower, and measure their effects on root diseases and grain yield of subsequent wheat and barley crops.
2. Document the long-term cumulative effects of minimum disturbance no-till planting practices on physical and biological properties of the surface soil.
3. Demonstrate and promote no-till farming practices and alternative crop rotations to growers and agricultural support personnel.
4. Assess the feasibility of alternative crops for low-rainfall dryland production areas.

KEY WORDS: No-till, low-rainfall, alternative rotations, dryland

STATEMENT OF PROBLEM: For most of a century the wide-spread practice of growing only one crop every other year in a tillage-based wheat-fallow rotation has degraded soils and contributed to environmental problems in low-rainfall (less than 12" annual) dryland areas of the inland Pacific Northwest. Soil organic carbon, and associated soil quality, are declining under the wheat-fallow system because of limited crop residue production, tillage, and the unproductive fallow period. Blowing dust from excessively tilled summer fallow is a major soil loss and air quality concern. In addition, water erosion from fall-planted wheat after fallow is often severe when rain or snowmelt occur on frozen soils. Growers in dryland areas are interested in no-till planting techniques and potential alternative crop rotations which reduce erosion, decrease soil-born diseases of cereals, enhance crop marketing opportunities, and hold potential to increase soil quality.

ZONE OF INTEREST: The low-rainfall (6-to 12-inch annual) dryland area of east-central Washington and north-central Oregon. This zone encompasses 3.5 million cropland acres.

ABSTRACT OF RESEARCH FINDINGS: We have completed two years of a long-term study to evaluate alternative cropping systems for low-rainfall dryland areas using minimum disturbance no-till. The experiment sites are near Ritzville (Ron Jirava farm) and Mansfield (Brad Wetli farm). We are comparing a 4-year rotation which includes two years of spring wheat followed by two years of broad leaf crops, continuous wheat, and continuous wheat - barley. Research highlights for 1998 are: Rhizoctonia root rot in cereals was lowest at Ritzville when the preceding crop was yellow mustard rather than cereals; wheat yields at both sites were highest when the preceding crop was yellow mustard; weed populations increase with broadleaf crops but can be effectively controlled when the rotation reverts back to cereals; aphid populations were much lower than in 1997 and; yellow mustard and safflower yields were reduced due to hot temperatures in late June and July. A new Cross-slot drill and a new plot sprayer will be available to this project in 1999 which will allow us increased flexibility and efficiency in planting and weed control.

RESULTS AND INTERPRETATION: This project, which began in April 1997, is evaluating diverse, annual, no-till cropping systems as a substitute for winter wheat - summer fallow. Research sites are located at the Ron Jirava near Ritzville in Adams county, and at the Brad Wetli farm NW of Mansfield in Douglas county. At both sites, the following rotations are studied:

The experimental design is a randomized block with four replications, and each portion of the rotation is planted each year (i.e., 28 plots are required at each site). The Ritzville site receives an average of 11.5 inches annual rainfall, soils are more than six feet deep, and elevation is 1850 ft asl. At Mansfield, rainfall averages 10.5 inches, soil is only 2-to-2.5 ft deep, and elevation is 2700 ft asl. The no-till drills used in the study are a grower-owned Flexicoil 6000 disc drill with 7.5" row spacing at Ritzville, and a Cross-slot disc drill with 10" row spacing at Mansfield. Both drills deliver seed and all fertilizer in a single pass through the field.

Plant Stand Establishment: Plots are fertilized at time of planting with nitrogen, phosphorous, and sulfur as indicated by soil tests in early spring. Seed rates in 1997 and 1998 were wheat 70-to-90 lb/a, barley 65-to-70 lb/a, safflower 20 lb/a, and yellow mustard 7-to-10 lb/a. Plant stands for all crops at both sites in 1997 and 1998 are shown in Table 1. Despite large seed size, stands of safflower have been relatively thin at both locations during both years. Yellow mustard stands were thin at both locations in 1998 which makes us wonder if safflower residue might have a phytotoxic effect on mustard seedlings. Acceptable stands of wheat and barley have been achieved at both locations each year.

Table 1. Plant stand establishment of four crops sown no-till at Ritzville and Mansfield in 1997 and 1998. Plots at Ritzville were sown with a Flexicoil 6000 disc drill and at Mansfield with a Cross-slot disc drill.

Crop	Location and Year†
	_____________Plants per ft2 ____________
	Ritzville		Mansfield
	1997 1998		1997 1998
Safflower after y. mustard	2.5	3.2	5.0	3.8
Y. mustard after safflower	1.8	0.7	7.0	2.4
Barley after wheat	8.6	15.3	10.3	20.4
Wheat after barley	---	20.7	---	22.2
Wheat after y. mustard	---	20.0	---	20.5
Wheat after wheat	9.6	18.6	10.9	26.2

† All crops were planted into spring wheat stubble in 1997, which was the first year of the study.

Weeds: Russian thistle, horse tail, and prickly lettuce were problem weeds in yellow mustard and safflower crops in 1997 and 1998. There are no registered "in-crop" herbicides broadleaf weed in yellow mustard or safflower, therefore control measures are limited to pre-plant herbicide application and competition. Broadleaf weed dry biomass in 1998 at time of harvest for yellow mustard and safflower averaged 700 lb/a at Ritzville and 1900 lb/a at Mansfield (Fig. 1). At Ritzville we are able to stagger planting of crops whereas in Mansfield, due to demands for the Cross-slot drill in other areas, we plant all crops on the same day. When safflower is planted early it emerges at the same time as Russian thistle (Mansfield), whereas Russian thistle is much less a problem when safflower planting is delayed (Ritzville) (Fig. 1). We will have a new Cross-slot drill available in 1999 which will allow us to optimize planting dates for crops at Mansfield.

Good weed control in barley and wheat was achieved at Ritzville in 1997 and 1998 with 6 oz. Salvo plus 0.3 oz. Harmony Extra applied during the tillering stage. There were no differences in 1998 in weed populations in wheat when the previous crop was either yellow mustard or wheat (Fig. 1), which shows that an elevated weed population in broadleaf crops can be brought back under control when the crop rotation returns to cereals. Weeds in barley and wheat were controlled with 2,4-D in 1997 at Mansfield, but we missed the opportunity to spray for broadleaf weeds in cereals in 1998, and wheat after yellow mustard had significantly more weeds than wheat after wheat (Fig. 1).

Fig. 1. Dry biomass of Russian thistle, horse tail, and prickly lettuce weeds at time of harvest for safflower, yellow mustard, and wheat as affected by rotation at Ritzville and Mansfield in 1998.

Root Rot Assessment: Rhizoctonia root rot is the most important disease of spring cereals planted directly into cereal stubble in the Pacific Northwest. Wheat and barley plants were dug from plots in 1998 at both sites to measure the severity of root rot disease. At least 5 plants were dug from each of 5 separate locations in every plot to make a composite sample. Jim Cook and his assistants determined Rhizoctonia root rot severity of both seminal roots and crown roots, along with other measurements.

The percentage of Rhizoctonia infection at Ritzville on both seminal roots and crown roots of cereals was lowest when yellow mustard was the preceding crop (Table 2). We are very encouraged with these data because Rhizoctonia can be devastating to cereals under no-till, and we believe broadleaf rotation crops are necessary to control this disease in continuous ultra low-disturbance no-till systems. No differences in Rhizoctonia infection were found at the Mansfield site in 1998.

Yield: Yields for all four crops grown at Ritzville were reduced in 1998 compared to the bumper harvest in 1997 (Table 3). Stored over-winter soil water and growing season rainfall were greater in 1997 than in 1998 (data not shown). In addition, hot air temperatures exceeding 90⁰F in late June and July 1998 stressed and reduced yields of yellow mustard and safflower. Where yellow mustard was the preceding crop, wheat yield wa 1.6 bu/a higher compared with wheat following wheat (Table 3).

Broadleaf yields were low at Mansfield which reflects a combination of very shallow soils, less than optimum planting date for the safflower, high weed density, and hot summer temperatures. Spring barley averaged 1.0 ton/a. Wheat yield exceeded 25 bu/a and was best on plots where yellow mustard was the previous crop (Table 3).

Table 2. Incidence of Rhizoctonia root rot on seminal and crown roots of spring wheat and spring barley 1998 at Ritzville and Mansfield in response to rotation. Crops are planted annually using no-till in a 4-year rotation at both sites.

Source: R.J. Cook

Table 3. Yields of four crops planted no-till at Ritzville and Mansfield in 1997 and 1998. These are second year results of a planned six-year alternative cropping systems project.

† All crops were planted into spring wheat stubble in 1997, which was the first year of the study.
‡ Wheat yields in 1998 at either the Ritzville or Mansfield site were not significantly different at the 5% probability level.

Other Measurements: Insect populations/ecology in all crops were measured several times throughout the growing season at both sites in 1997 and 1998 (Bob Gillespie) and we plan to write a scientific journal and popular article from these data in the next year. Herbicide screening experiments for broadleaf weed control in yellow mustard and

Fig. 2. Water use and dry matter production of eleven spring-planted crops at Lind, Ritzville, and Harrington in 1998.

safflower were conducted at the Ritzville site (Joe Yenish). A yellow mustard screening trial was conducted at the Lind Dryland Research Station by Jack Brown from the University of Idaho. Baseline soil samples have been collected at both sites (Ann Kennedy). Root disease assessment will continue (Jim Cook).

COMPANION STUDIES: A long-term no-till project was initiated at the WSU Dryland Research Station at Lind in 1998. We are using the Cross-slot drill to annually plant wheat, barley, oats, and safflower as spring crops and to compare winter wheat (when fall rainfall allows) to spring wheat on an annual basis.

We have compared annual no-till spring wheat with winter wheat - summer fallow in a replicated study at the Doug Rowell farm in the Horse Heaven Hills since 1997. The site receives an average of only 6 inches average precipitation and wind erosion from summer fallow is a recurrent problem.

In collaboration with Chad Shelton of Western Farm Service, the PI measured soil water use and dry matter production of eleven crops grown during 1998 at the WSU Dryland Research Station at Lind, the Donald and Doug Wellsandt farm near Ritzville, and the Karl Kupers farm near Harrington. Total water use and final dry matter production at each of the sites is shown in Figure 2. If you have questions about any study mentioned in this report contact Bill Schillinger at (509) 659-0355 or email schillw@wsu.edu.

INTERACTION (COOPERATION) WITH OTHER SCIENTISTS CONDUCTING RELATED ACTIVITY: In addition to the co-investigators of this project, the PI is cooperating with: Frank Young, USDA/ARS Pullman, on the Ralston integrated spring wheat project as well as research on the ecology and growth of Russian thistle; Keith Saxton, USDA-ARS Pullman, on development of a new Cross-slot no-till plot drill; Doug Young, WSU, on the economics of several cropping systems research projects, Tim Fiez, WSU, on row spacing effects of direct seeded spring wheat and spring barley; Dave Evans, WSU Prosser, on dryland cropping systems in the Horse Heaven Hills: Steve Albrecht, Paul Rasmussen, Clyde Douglas, Bill Payne, and Don Wysocki, USDA-ARS and OSU Pendleton, on planning future collaborative cropping systems research endeavors; Ed Donaldson, Bob Allan, and Steve Jones, WSU, on winter wheat seedling emergence from deep planting depths; and with Tom Lumpkin, WSU, and Chad Shelton, Western Farm Services, on evaluating alternative crops.

PUBLICATIONS AND PRESENTATIONS:

Schillinger, W.F., R.J. Cook, and R.I. Papendick. 1998. Alternative cropping systems using no-till for low-precipitation dryland areas. American Society of Agronomy annual meeting, Baltimore, MD, October 18-22. Agronomy Abstracts p. 271.

Schillinger, W.F. 1998. Alternative crop rotations using no-till in low-precipitation dryland areas. Soil and Water Conservation Society annual meeting, San Diego, CA, July 5-8. Journal of Soil and Water Conservation 52(2):165.

Schillinger, W., R.J. Cook, R. Papendick, R. Veseth, H. Schafer, K. Saxton, R. Gillespie, A. Kennedy, J. Yenish, and J. Driessen. 1998. Alternative annual crop rotations for low-rainfall dryland using no-till. p. 55-58. In: 1998 Field Day Proceedings: Highlights of Research Progress. Department of Crop and Soil Science Technical Report 98-2, Washington State University, Pullman, WA.

Schillinger, W., R. Jirava, B. Wetli, R.J. Cook, R. Papendick, R. Veseth, H. Schafer, R. Gillespie, A. Kennedy, J. Yenish, K. Saxton, and D. Wysocki. 1998. Alternative crop rotations using no-till in low-rainfall dryland areas. pp. 71-74. In: Proceedings of the Northwest Direct Seed Intensive Cropping Conference, R. Veseth (ed.), January 7-8, Pasco, WA.

Schillinger, W.F. 1998. Oral presentations on this project were made at the: PNW Direct Seed Conference in Pasco on January 7 (500 attendance); Farm Forum in Spokane on January 14 (40); Making No-Till Work conference in Ritzville on January 22 (85); Foster Creek Conservation District annual meeting in Mansfield on February 5 (80); WSU Lind Field Day on June 11 (190): Benton County Wheat Growers field day on June 16 (60); Twilight tour at the Jirava research site on June 18 (40); Foster Creek Conservation District field day in Douglas county on June 30 (40) and; Douglas-Grant counties wheat grower association annual meeting in Moses Lake on November 6 (40).

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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