Project Number: 5348-21610-002-00
Start Date: Oct 21, 2013
End Date: Oct 20, 2018
(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.