2012 Annual Report
1a.Objectives (from AD-416):
The overall goal of this project is to identify improved forage production techniques that will contribute to decreased costs of livestock production and increased income on limited-resource farms. The purpose is to develop low-input forage production techniques that are appropriate for resource-poor producers, and that will increase livestock carrying-capacity, improve early- and late-season forage production and reduce or eliminate expenditures for off-farm feed supplies. This purpose will be met by evaluating combinations of forages grown in mixtures or sequences, and by developing low-input management methods that will enable their use as a productive and persistent complement to, or replacement for, unimproved or degraded pasture. Specifically, we will focus on the following objectives:
Objective 1. Identify appropriate forage species and develop low-input techniques for increasing forage production and extending the grazing season on degraded or unimproved pastures to increase year-round availability of homegrown forage and provide economically and environmentally sustainable forage production systems for under-served, resource-limited livestock producers.
Sub-objective 1A. Assess the productivity and persistence of non-traditional warm- and cool-season grass and legume mixtures for utilization under grazing.
Sub-objective 1B. Identify the most effective low-input establishment techniques (no-till drilling, broadcasting or self-seeding) for cool- and warm-season grass and legume forages established in mixtures with existing, unimproved pastures of native species or bermudagrass.
Objective 2. Determine the cause(s) of poor establishment of cool-season grasses and legumes following self-seeding or over seeding into established pastures, such as loss of seed quality, hydration/dehydration cycles, temperature or moisture stress, and adverse soil characteristics such as compaction or plant litter.
Objective 3. Determine the usefulness of accumulated temperature (degree days) as an aid to timing of pasture management operations such as fertilizer application and harvesting, in order to minimize competition in cool- and warm-season grass mixtures during seasonal transitions.
1b.Approach (from AD-416):
Replicated experiments will be undertaken in controlled-environment or in small-plot field trials to measure management effects on establishment, production and persistence of cool-season forages grown in mixtures with warm-season pasture. Processes of regeneration and persistence in cool-season grasses and legumes established by minimal tillage in sequence with unimproved warm-season pasture will be studied. Low-input methods of sowing that will improve the efficacy and predictability of establishment of forage grasses and legumes and that allow improved early-season production from cool-season forages will be evaluated. Indicators of the onset and termination of forage growth will be determined to facilitate management and to minimize or eliminate interference between cool- and warm-season forages. Results from the project will identify forage management systems adapted to low-input farms and forage mixtures that enhance and extend the productive grazing period of pastures.
In the aftermath of the exceptionally hot and dry weather experienced during 2011 perennial forage trials were terminated because of significant sown crop loss. Summer dormant tall fescues partially regenerated in early CY2012, and plant population and yield estimates were made on these cultivars, but summer active tall fescue cultivars did not recover from the heat and drought stresses of 2011. Field-scale validation and demonstration of overseeding Italian ryegrass that was unsuccessful in 2011 was repeated on two small farms in FY2012. Study of Nitrogen use efficiency in annual ryegrass was continued in FY2012.
Summer-dormant tall fescue for the southern Great Plains. The lifetime productivity of cool-season perennial grass pastures is compromised by limited persistence under the heat and moisture stresses characteristic of the summer months in the southern Great Plains. Recently introduced summer dormant cultivars of tall fescue may provide increased tolerance of climatic stresses and improved productivity. Field experiments showed, however, that over 3 or 4 years' life of pasture, summer dormant tall fescue cultivars were less productive than conventional summer active tall fescues. Increased survival of summer dormant cultivars following extreme drought conditions was not sufficient to offset their lower productivity. Earlier results showing that year-round forage production (warm- and cool-season production) was greater when cool-season grasses were no-till overseeded into existing warm-season pasture than when sown into a cultivated seedbed were confirmed.
Bartholomew, P.W., Williams, R.D. 2012. Leaf damage in cool-season grasses subjected to simulated hoof pressures. Forage and Grazinglands. Available: http://www.plantmanagementnetwork.org/fg/.
Bartholomew, P.W., Schneider, J.M., Williams, R.D. 2011. Pasture residue amount and sowing method effects on establishment of overseeded cool-season grasses and on total annual production of herbage. Grass and Forage Science. 66(4):560–568.