2011 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.
Accomplishment of field experimental work during FY2011 was significantly compromised by abnormally dry weather throughout the normal growing period for cool-season grass (October to May). Measures that have been possible will contribute to a better understanding of forage production potential under adverse conditions. Field-scale validation and demonstration of overseeding Italian ryegrass, based on results from previous work under this project, were undertaken with a cooperating small producer, but were ultimately unsuccessful because of the adverse weather conditions. This effort will be repeated in FY 2012. Field studies of the long-term viability of surface or near-surface sown ryegrass seed, undertaken as part of a larger investigation of factors affecting the success of self-seeding in annual ryegrass, were completed. Italian ryegrass did not display any primary or secondary dormancy when placed in the field at the end of July and sampled monthly thereafter. The greatest germination occurred in August and September. Seed germination, as well as the number of seedlings observed, declined from August through to March of the following year. The results support earlier field observations that Italian ryegrass does not form an extensive seedbank, and yearly reseeding will probably be necessary for sustained production of forage. Seed-predator preference studies of warm- and cool-season forage grasses have been completed, and analysis of these data is in progress.
Reduced-input overseeding for cool-season grasses. The potential for cost savings, reduction in risk of soil erosion or problems associated with pasture establishment by conventional tillage has created significant interest in use of no-till methods for sowing forage grasses. However, use of no-till methods by small and resource-limited producers may be limited by access to the specialized seeding equipment normally employed for no-till sowing. Scientists of the Grazinglands Research Laboratory, based at Langston, OK, demonstrated that satisfactory no-till establishment of cool-season grasses could be achieved by broadcast seeding into warm-season grass stubble, a method that is well adapted to the limited resources of small producers. The work also showed that broadcast seeding of cool-season grass was less damaging to yield of warm-season grass in the following season than was sowing of cool-season grass with a no-till seeder.
Williams, R.D., Bartholomew, P.W. 2011. Hairy vetch (Vicia villosa) seed size affects germination response to coumarin. Allelopathy Journal. 27(2):237-244.