Project Number: 3655-21000-056-00
Project Type: Appropriated

Start Date: Jan 25, 2013
End Date: Jan 24, 2018

Objective:
Objective 1: Develop appropriate defoliation (grazing and harvested) and nitrogen application management guidelines for temperate grass-legume pastures of the North Central and Northeastern USA to improve seasonal yield distribution, extend the grazing season, and improve the efficiency and utilization of energy inputs. Sub-objective 1A. Determine the influence of manure source and time of application on temperate grass productivity, seasonal yield distribution, nutritive value, and persistence, pasture composition, and soil chemical and physical properties. Sub-objective 1B. Determine the influence of nitrogen source, nitrogen application date and rate, and defoliation management on the productivity and persistence of red clover grown with orchardgrass. Objective 2: Improve establishment, harvest management, and storage methods to reduce nitrogen inputs, increase the profitability of crop rotations, increase the recovery of dry matter and nonstructural carbohydrates, improve the energy density of baled hays, and mitigate the negative effects of rainfall on ensiling, storage, and feeding characteristics of rain-damaged silages. Sub-objective 2A. Identify optimal plant spacing to maximize yield of biomass alfalfa. Sub-objective 2B. Develop improved methods for interseeding alfalfa into maize to bring alfalfa into full production the following year. Sub-objective 2C. For large hay packages, quantify the effects of several baling factors on subsequent preservation performance of stored hay. Objective 3: Improve pasture grass and legume production systems through increases in establishment capacity, persistence, productivity, resilience to climate extremes, and quality. Sub-objective 3A. Measure comparative effectiveness of mass selection, maternal half-sib selection, and marker-assisted paternal half-sib selection for persistence and biomass yield in diploid red clover. Sub-objective 3B. Determine optimal plant-selection age after establishment to simultaneously maximize genetic gain for persistence and biomass yield of red clover. Objective 4: Improve profitability, conversion efficiency, and adaptability to climatic variation in forage and bioenergy crops. Sub-objective 4A. Quantify the effect of decreased lignin and decreased etherified ferulates on agricultural fitness of three temperate pasture species, including their tolerances to drought, heat, and grazing. Sub-objective 4B. Use a biomimetic model based on the artificial lignification of plant cell walls to identify new lignin bioengineering targets for improving the fermentability of forage and biomass crops. Sub-objective 4C. Create and evaluate a series of upland x lowland switchgrass hybrids of differing origins to determine if heterosis is related to geographic origin of either parent.

Approach:
Objective 1. Solid and liquid manure applications will be evaluated in a series of grazing experiments designed to improve seasonal availability of nutrients and seasonal distribution of pasture productivity. Defoliation and manure application treatments will be applied to grass-clover mixtures to identify combinations that increase the competitiveness of red clover in mixed grazed swards. Objective 2. High vs. low-density plant spacing will be evaluated to determine the effect on biomass yield for high-biomass alfalfa cultivars. Gibberellin-based growth regulator treatments will be evaluated for their effect on establishment and seeding-year biomass yield for alfalfa interseeded into maize. Propionic acid preservatives will be evaluated to determine their effect on reducing spontaneous heating and nutrient loss of large-rectangular bales of alfalfa hay. Objective 3. The comparative effectiveness of mass selection, half-sib selection, and marker-assisted half-sib selection will be determined in an empirical study designed to improve persistence and forage yield of red clover. The optimal age for selection of red clover plants will be identified by evaluating empirical gains from selection for persistence and forage yield on selection nurseries of various ages and degrees of plant mortality. Objective 4. The effect of lignin and etherified ferulates on persistence and forage yield will be evaluated in a series of field experiments designed to evaluate progeny with high or low levels of each cell-wall component in three grass species. The direct effects of monolignol substitutes on cell-wall fermentability and saccharification will be evaluated by using these novel compounds, compared to classical monolignols, as substrates for artificial lignification of maize primary cell walls. Heterosis between upland and lowland switchgrass ecotypes will be evaluated in a series of experiments to quantify hybrid vigor and to identify sources of variation that contribute to variation in hybrid vigor.