This project plan describes cropping systems research conducted jointly by the Soil and Water Conservation Research Unit (Pendleton, Oregon) and the Land Management and Water Conservation Research Unit (Pullman, Washington). The purpose of this project is to advance oilseed production reliably into drier areas in the Columbia Plateau of the interior Pacific Northwest (PNW). Specific objectives are listed below. Objective 1: Identify cultural practices for expanding oilseed production in the drier acreage portions of Columbia Plateau (Pullman, all of Obj 1). Sub-objective 1A: Assess the effectiveness of crop residues and the stripper header for maintaining soil moisture for tillage-based and chemical fallow systems. Sub-objective 1B: Identify best varieties and crop management practices for optimizing seed yield and quality attributes, and managing weeds in spring oilseeds. Objective 2: Identify and evaluate dryland cropping systems comprised of cereals and oilseeds that can be used to produce biofuels and derive environmental benefits (Pendleton all of Obj 2). Sub-objective 2A: Evaluate the yield performance of cereal-based rotations that include oilseeds. Sub-objective 2B: Determine whether diversified wheat-oilseed rotations compared to WW-SF provide belowground benefits derived from changes in microbial communities. Sub-objective 2C: Measure dust and PM10 emissions from diversified crop rotations. Sub-objective 2D: Determine the effect of crop sequences on overwinter infiltration, rain capture, and soil water storage for spring crops. Sub-objective 2E: Calibrate and use SWAT to determine potential changes in crop productivity, hydrology, and sediment loads resulting from a shift from conventional to diverse cropping systems. Objective 3: Compare farm income from conventional winter wheat-summer fallow with diversified cropping systems (Pendleton and Pullman). Objective 4: Conduct life cycle assessments of different cultural practices and dryland cropping systems to evaluate resource use, energy efficiency, water consumption, greenhouse gas (GHG) emissions, and waste production (Pendleton and Pullman).
(Pullman only) 1A: Hypothesis-Soil moisture will be increased in chemical fallow by planting winter triticale and harvesting with a stripper header compared to a winter wheat-tillage fallow system. The study consists of four cropping/harvesting systems in a randomized complete block design with four replications. The systems include; the traditional fallow-winter wheat with wheat harvested using a conventional header, chemical fallow-winter wheat with wheat harvested with a stripper header, chemical fallow-winter triticale harvested with a conventional header, and a stripper header. The long-term goal of this study is to plant winter canola into chemical fallow when soil moisture is 4 to 6 cm from the surface compared to summer fallow where soil moisture is >13 cm deep. Data collected includes crop yield and biomass, gravimetric soil water content (spring and post-harvest) to 1.8 m, organic matter and, soil profile NO3-N and NH4-N to 1.2 m. Water use efficiency will be determined by the ratio of crop yield to spring soil water content minus post-harvest soil water content. Soil water content will be corrected for precipitation. Three 1.8 m soil cores per plot will be composited by 0.3-m increments at each sample date. Analyses of variance (ANOVA) of crop yield, biomass, organic matter, and soil N will be performed using a generalized linear mixed model in PC-SAS with crop rotation as the fixed effect, and replication and crop rotation x replication as random effects. How soon winter canola can be planted will depend on how much residue is produced and how much moisture is received. 1B: Hypothesis—Herbicide-resistant spring canola planted in narrow rows will improve crop yield and oil quality compared to either the same varieties planted in wide rows or spring carinata planted in both row spacings. This study will compare the grain yield and oil quantity of two spring oil seed crops, B. napus canola and B. carinata, planted in two row spacings. Oilseed crops include; “Genuity” early and late maturing spring canola B. napus; “InVigor” spring canola B. napus; and, “Resonance A100” spring B. carinata. “Genuity” spring canola is resistant to Roundup and “InVigor” spring canola is resistant to Liberty herbicides. “Resonance A100” is not an herbicide resistant variety of spring carinata. Crops will be planted mid-April with a JD9400 no-till drill at 5.5 kg/ha in row spacings of 17 and 34 cm. Treatments will be replicated 4 times and arranged in a RCB design. Varieties are main plots and row spacings are split-plots. Crop populations will be determined by counting plants in 2 rows in five 1 m lengths in each plot. Crop yield will be determined by machine harvest. Oil quality and quantity will be determined using a scaled oil extractor to simulate industrial scale processing. ANOVA of crop yield and seed oil content will be performed using a generalized linear mixed model in PC-SAS. Fixed effects will be crop, row spacing, and their interaction. Field experiments are subject to weather variances and the studies may have to be extended in duration. Random effects will be replication and crop x replication. Objectives 3 and 4 will be joint efforts.
During FY14, we conducted winter canola variety trials throughout the low-rainfall, winter wheat production area; winter canola establishment in high residue, stripper header conditions; and management of feral rye in winter canola. These research projects all support Objective 1 to identify cultural practices for expanding oilseed production in the drier acreage portions of the Columbia Plateau. In FY13, 12 varieties were planted at two locations in Washington. Varieties were from two university breeding programs, a European country, and a private seed company. Varieties included herbicide tolerant varieties as well as conventionally bred varieties. Yields ranged from 1490 lbs/A to >3000 lbs/A for both sites. Winter survival ranged from 62 to 77% for site 1 and 77 to 99% for site 2 indicating environmental conditions affect winter survival. This information is essential for growers to determine which variety is best adapted to their location. In FY14, 14 varieties were planted in various locations. We are conducting collaborative research with Washington Statue University (WSU) and Rock Lake Conservation District to evaluate the use of a stripper header to increase residue to retain soil moisture. In the fall of 2013, we no-tilled winter canola into 3-ft high standing winter triticale stubble harvested with a stripper-header. Winter canola establishment was 95% in the stripper-header treatment and 40 to 60% in the conventional cutter bar treatment.
1. Winter canola stand establishment in the Pacific Northwest. Growers in this production zone of the Pacific Northwest have not been planting winter canola because of poor stand establishment in summer fallow. An ARS agronomist at Pullman, Washington, conducted a five year study in which winter canola was planted at four pounds per acre in August when air temperatures were about eighty-five degrees fahrenheit for several days. He found that canola stand establishment and subsequent yield were improved greatly over conventional planting methods. During this study period, growers in two northern Washington counties increased winter canola acreage from less than hundred acres to more than eleven thousand acres.
Young, F.L., Whaley, D.K., Pan, W.L., Roe, D., Alldredge, J.R. 2014. Introducing winter canola to the winter wheat-fallow region of the Pacific Northwest. Crop Management. DOI: 10.2134/CM-2013-0023-RS.
Young, F.L., Ogg Jr, A.G., Alldredge, J.R. 2014. Postharvest tillage reduces Downy Brome infestations in winter wheat. Weed Technology. 28:418-425.