1a. Objectives (from AD-416):
This research project builds upon the cooperative research studies and collaborations of 40+ years between Colorado State University (CSU) and the USDA-ARS Central Great Plains Research Station in Akron, CO (ARS-Akron). This cooperative research project will continue mutual collaborations on the development of bio-energy crop production systems for the Central Great Plains region (CGPR), and assist in the development of biobased technologies to provide opportunities for the production of value-added products that enhance economic benefits to U.S. farmers. ARS-Akron scientists collaborate with CSU scientists on the agronomic development of alternative bio-energy crops for the CGPR. These include: (a) variety testing and selection of the alternative oilseeds spring and winter canola and camelina; (b) an experiment with skip-row sunflower; and (c) crop sequencing and seedling establishment studies with canola and camelina. The hypothesizes of these experiments are: (1) small seeded alternative oilseeds (canola and camelina) have a best seeding depth, planting date and cropping sequence for optimal stand establishment and final yield; (2) small seeded oilseeds will have a better yields when planted in rotation sequence with specific dryland crops; and (3) alternative oilseeds (sunflower, canola) have an optimal planting architecture that may be different then typical dryland crops. ARS-Akron presently has several ongoing projects with winter wheat to: (a) advance understanding and quantitative knowledge base for crop responses and develop tools to guide optimal management; and (b) quantify the N use efficiency of select wheat varieties to improve the productivity and quality of winter wheat in dryland cropping systems. The specific research objectives include: (1) Defining crop-sequencing effects on winter wheat yield and the yields of other dryland crops in alternative no-till dryland cropping systems; (2) N requirement and N response of hard red and hard white winter wheat in no-till and reduce dryland cropping systems; (3) Evaluating wheat cultivar susceptibility to apparent allelopathic effects of proso millet plant tissue extracts on wheat germination; and (4) Long term wheat-yield and soil quality response to different residue, tillage and weed management strategies. The proposal is to quantify the N use efficiency (NUE) differences of a select group of winter wheat varieties to a variable N fertility regime. Hypothesis: Different lines of winter wheat will have a different yield response to available N and a different NUE. Likewise, different wheat varieties may have a different grain quality response to applied N (milling, dough mixing and baking).
1b. Approach (from AD-416):
Alternative bio-energy crops component: Traditional replicated factorial and split plot experimental designs will be used to test various treatment combinations of crop sequence, seeding depth and date and planting architecture under dryland and limited irrigation in traditional field plots. Measurements will include crop water use, stand establishment parameters, biomass yield, grain yield and various yield components. Data will be analyzed using ANOVA and traditional mean separation statistical procedures. Both CSU and ARS personnel will be involved in experimental design and both collaborate on plot establishment, plot maintenance, plot sample collection, grain and biomass harvest, data reduction, analysis and interpretation. Wheat varieties component: A field plot experiment will be established at ARS-Akron where select varieties of winter wheat (20 lines) will be planted in a split-plot arrangement with N regime as main plots and variety by N regime as the subplots all replicated 3 times. Five (5) N fertilizer regimes will be imposed: a no N rate plot as a check plot, a 25, 50, 75 and 100 kg ha-1 N rate treatment. Measurements: Wheat grain yield and yield components (kernel number and weight), crop phenology (heading and anthesis dates, physiological maturity), and grain N on all experimental units (5 N fertility regimes x 20 lines x 3 reps ~ 300 grain yield/grain N measurements); biomass yield, and N uptake, at anthesis to calculate apparent N recovery (APN) and response index (RI) of each variety (300 biomass and biomass-N measurements). Soil inorganic N will be measured incrementally in the top 120-cm of the soil profile (4-feet) just prior to N application and planting, and again just after wheat harvest in each plot (0-15cm, 15-30 cm 30-60, 60-90, and 90-120 cm increments). Soil water at planting and at harvest will be collected on half of the N by variety combinations to estimate soil-water use for the whole experiment and of select varieties of winter wheat to the same 120 cm depth and in the same increments as inorganic N. Grain quality measurements would be on a subset of select treatments from the larger study. Experimental units measured will be decided based on yield and apparent N recovery measurements found in the larger study. Quality measurements will include single kernel characterization (weight, width, diameter), Quadrumat Senior milling, Mixograph, and pup-loaf baking tests.
3. Progress Report: