Brief Summary of Minutes of Annual Meeting

Accomplishments:

Renewal of the NC1182 Project.  Within Forage-Based Livestock Production Systems, the new project is exploring innovative and ecologically based methods to further understand the impact of a changing climate on N cycling,  management practices including different forages which will more efficiently  manage N, and have also added a focus on quantitative similarities and differences of managements’ impact on N cycling in difference ecological regions. 

Three different nitrogen balance studies were completed with sheep.  Feces and slurry from sheep digestion and nitrogen balance studies were applied to forage plots and subsequent ammonia and greenhouse gasses were measured.

Identified practices that optimize legume establishment and persistence was addressed with an experiment that evaluated "Establishment of Perennial Legumes with an Annual Warm-Season Grass as a Companion Crop".  

Quantified effects of pasture management strategies on N use efficiency by ruminant animals and N cycling in herbage and soils of grassland agro-ecosystems was addressed with a 3-year pasture experiment that evaluated feasibility of interseeding sorghum-sudangrass into established smooth bromegrass pastures using only grazing to prepare the pastures for seeding and whether there were any differences between fertilized pastures and pastures interseeded with legumes.

Evaluated the effect of different EE N formulations (ESN, methylene urea, SuperU, and a 75% ESN: 25% urea blend) and untreated urea on yield, nutritive value, and legume persistence in a ‘Wrangler’ bermudagrass (Cynodon dactylon) and ‘Durana’ white clover (Trifolium repens) mixture. Nitrogen was applied at four rates (0, 112, 224, and 448 kg N ha^-1) in two equal applications at the University of Kentucky Spindletop Research Farm in Lexington, KY using a randomized complete block design. During the establishment year, the encroachment of volunteer white clover plants resulted in only a small decline in the clover population of the highest N rate but became larger among all treatments in the second and third years. Averaged over the three years of the study, all EE N sources maintained white clover populations similar to the unfertilized grass/clover control, but only ESN kept clover composition greater than standard urea. Total forage yields linearly increased along N rates in all years, ESN’s ability to maintain clover resulted in higher nutritive value.  

Evaluated the effect of different enhanced efficiency (EE) N formulations [ESN, Agrotain treated urea (ATU), and a 75% ESN: 25% urea blend] and untreated urea on yield, nutritive value, and legume persistence in a ‘KY 31’ tall fescue (Festuca arundinacea) and ‘Kenland’ red clover (Trifolium pratense) mixture. Nitrogen was applied at four rates (0, 112, 224, and 336 kg N ha^-1) in two equal applications at the University of Kentucky Spindletop Research Farm in Lexington, KY using a randomized complete block design. During the first year, total seasonal yield increased with increasing N rates. There was no difference in forage yield among N rate or N source in the second growing season. Clover content declined with increasing N rates, ESN and the ESN+Urea blend maintained more clover than ATU and urea.        

Short-term Outcomes

Outputs:  

• We quantified grazing managements impact on spatial and vertical distribution of N, P, C and blk density in southeastern grazing systems.

• We found that establishment of sorghum-sudangrass interseeded into smooth bromegrass pastures was poor, whether pastures were managed as N-fertilized monocultures or grass-legume mixtures. Thus, we recommend that if producers were to adopt this strategy to improving productivity of pastures that they focus on getting best establishment of the summer annual.  At this time, however, we have not established proven strategies for doing so.  To improve beef cattle production, pasture managers should focus on maintaining a good mix of perennial cool-season grasses to legumes (70:30 ratio) as principle components of vegetation.

• We found that the use of locally sourced bioinoculant, LEM significantly increased N mineralization 1 week after application of LEM in Lolium multiflorum haying system.

• Alfalfa and tall fescue were harvested after a killing frost and ensiled in different proportions, and subsequent silages were offered to sheep. Addition of tall fescue improved ensiling characteristics of the forages, but nitrogen use measurements all decreased with increasing proportions of tall fescue in the silages.

• Sericea lespedeza hay was either not offered, or offered at 9, 18, or 27% of the diet dry matter to sheep offered a basal diet of alfalfa silage. Dry matter and organic matter digestibility decreased with increasing sericea lespedeza.  Urinary nitrogen excretion decreased, and fecal nitrogen excretion increased with increasing sericea lespedeza in the diet.

Educational Aids or Curricula: we developed curricula to increase undergraduate student understanding of principles basic to the establishment, management, and utilization of forage crops and pastures. Topics include plant identification, cultivar selection, seeding, fertilization, irrigation, forage quality and utilization, hay and silage preservation, and grazing management.

Activities:

Began collecting electrical conductivity, soil N and C, forage quality and water quality data of variable rate study.  We have found a somewhat strong relationship with permanaganate carbon to nitrate in soil.  We will further explore this relationship to high nitrate concentrations in hay.

Evaluating the effect of different enhanced efficiency N formulations [ESN, Agrotain treated urea (ATU), and SuperU] and untreated urea on yield and nutritive value in a ‘KY 31’ tall fescue (Festuca arundinacea) stockpiled pasture. Nitrogen was applied at four rates (0, 45, 90, and 135 kg N ha^-1) in one fall application.

Milestones:

Identified and acquired graduate student to begin research on variable rate N application mixed forages harvest for hay.  Undergraduate student mentee was awarded undergraduate research funding to determine relationship of Veris collected spatially explicit electrical conductivity, permanganate carbon, soil organic carbon, and bulk density to plant available N. 

Payne, K.M., B.M. Goff, S.R. Smith, J.H. Grove, M.S. Coyne, J.W. Lehmkuhler. 2018. Enhanced efficiency nitrogen fertilizer effect on pasture productivity. KFGC Eastern Field Day, Morehead, KY. 6 Sept.

Payne, K.M., B.M. Goff, S.R. Smith, J.H. Grove, M.S. Coyne, J.W. Lehmkuhler. 2018. Enhanced efficiency nitrogen fertilizer effect on pasture productivity. Donald Sparks IPSS Graduate Research Symposium, Lexington, KY. 23 March.

Forage News Articles (distributed electronically and available online):

• 31 Aug 2018, Featured Publication: Forage Establishment
• 31 Aug 2018, Forage Timely Tips: September
• 31 Aug 2018, New Crimson Clover Available: Kentucky Pride
• 30 Jul 2018, Forage Timely Tips: August
• 29 March 2018, Featured Publication: Alfalfa Management Guide
• 31 Jan 2018, Frost Seeding Red and Ladino White Clover Soon
• 19 Dec 2017, Maximizing Success with Frost Seedings of Clover
• 1 Dec 2017, Don’t Trip on Triple-19

Impacts:

Uneven distribution of C, N, and P in grazing systems can be linked to management practices such as location of feeding areas and shade Dahal et al., 2018, Hendricks 2019 which identified the need to more efficiently utilize grazing lands and the need to feed cattle uphill and away from riparian areas to reduce the loss of nutrients  

Use of a bio-innoculate can increase N availability one week after application of swine effluent fertilizer and the bio-inoculate “locally effective microorganisms which can improve N use efficiency when animal waste is used as an N fertilizer.

Long- term Outcomes:

Activities :

From the works in past years and 2019 and the last two years of discussions we formulated the objectives of the 10/01/2019 to 09/30/2024 NC1182 project cycle.

Milestones: Developed new cycle NC1182 objectives to better understand n cycling variations with ecosystem, landscape and management.

Indicators:

We have completed several studies that have resulted in peer reviewed publications, presentations, Field Days, and Extension Bulletins.

Publications

1. George, B., H. Hillhouse, B.E. Anderson, and A. Guretzky. 2018. Establishment of interseeded annual warm-season grasses in smooth bromegrass pastures. In 2018 ASA and CSSA Meeting Abstracts [Online]. Available at https://scisoc.confex.com/scisoc/2018am/meetingapp.cgi/Paper/113271 (verified 14 Feb. 2020).

2. George, B., H. Hillhouse, B. Anderson, and Guretzky. 2019. Variables affecting establishment of sorghum-sudangrass in smooth bromegrass pastures. Cropwatch [Online]. UNL Institute of Agriculture and Natural Resources. IANR Media. Available at https://cropwatch.unl.edu/2019/variables-affecting-establishment-sorghum-sudangrass-smooth-bromegrass-pastures (verified 14 Feb. 2020).

3. La Vallie, M. 2019. Establishment of perennial legumes with an annual warm-season grass as a companion crop. M.S. Thesis. Univ. of Nebraska-Lincoln (Advisors A. Guretzky/W.H. Schacht).

4. Niyigena, V., P. Coffey, W. K. Coblentz, D. Philipp, R. T. Rhein, A. N. Young, J. D. Caldwell, and B. C. Shanks. 2019. Intake and digestibility by gestating sheep offered alfalfa silage wrapped with plastic with or without an oxygen-limiting barrier after extended time delays. An. Feed Sci. Technol. 254:114193.
5. Hendricks, Taylor*, H. Franklin, S. Dahal, D. Hancock, L. Stewart, M. Cabrera, and G. Hawkins. 2019. Distribution of Soil Carbon and Bulk Density in Ten Southern Piedmont Grazing Systems as influence by management and landscape. Journal of Soil & Water Conservation 74 (4):199-209.

6. Ney, Laura*, Dorcas Franklin, Kishan Mahmud, Miguel Cabrera, Dennis Hancock, Mussie Hateselassie, and Quint Newcomer.   Examining trophic-level nematode community structure and nitrogen availability of swine effluent to forage crops.  Applied Soil Ecology 130:209-218.

7. Schick, B.D., A. Guretzky, W.H. Schacht, and M. Mamo. 2019. Dietary nutritive value, dung quality, decomposition, and nutrient movement into soil in smooth bromegrass pastures. Crop Science 59: 1294-1308.

8. Dahal, Subash*, Dorcas H. Franklin, Miguel L. Cabrera, Dennis W. Hancock, Lawton Stewart, Anish Subedi, Kishan Mahmud, Laura Ney. Spatial distribution of inorganic nitrogen in pastures as affected by management, landscape, and cattle locus.  47(6):1468-1477.

Abstracts:

• Althaber, C., K. P. Coffey, D. P. Compart, S. Shelby, M. Hays, V. Niyigena, J. Bignar.   Determining the optimal dose of microbial enzyme to enhance fiber digestion.  ASAS, Annual Meeting, Austin, TX.
• Althaber, C., K. P. Coffey, D. P. Compart, S. Selby, M. Hays, V., Niyigena, J. Bignar.   Determination of microbial enzyme efficacy on fiber digestion of bermudagrass hay supplemented with either ddgs or corn. ASAS, Annual Meeting, Austin, TX.
• Diaz, J. M., D. Philipp, K. Coffey, P. A. Beck, V. Niyigena, R. Rhein.   Effects of two sward heights on forage nutritive value, rumen digestion, and grazing behavior of steers grazing non-endophyte infected tall fescue pastures.  J. Anim. Sci. 97, Suppl. S1:36.  http://doi.org/10.1093/jas/skz053.080.
• Diaz, J., K. P. Coffey, W. K. Coblentz, D. Philipp, V. Niyigena, M. C. Pruden, D. Myers.   Digestibility of sheep offered tall fescue, meadow fescue and orchardgrass grasses ensiled with slurry or commercial urea fertilization.  ASAS, Annual Meeting, Austin, TX.
• Niyigena, V., K. P. Coffey, W. K. Coblentz, D. Philipp, C. Althaber, R. T. Rhein, and M. C. Pruden. 2019. Intake, digestibility, and rumen fermentation in sheep offered alfalfa silage alone or alfalfa and tall fescue mixtures harvested after a killing frost. Annual Meeting of ASAS. July 8-11, 2019. Austin, TX.
• Niyigena, V., K. P. Coffey, W. K. Coblentz, D. Philipp, M. C. Savin, J. Zhao, J. Diaz, S. P. Park, and S. l. Shelby. 2019. Effect of supplementing different proportions of sericea lespedeza with alfalfa silage on intake, digestibility, and nitrogen balance in sheep. Annual Meeting of ASAS. July 8-11, 2019. Austin, TX.
• Niyigena, V., K. P. Coffey, W. K. Coblentz, D. Philipp, M. C. Savin, J. Zhao, J. Diaz, S. P. Park, R. T. Rhein, and M. C. Pruden. 2019. Effect of supplementing different proportions of Lablab purpureus with alfalfa silage on intake and digestibility in gestating sheep. Proc. Southern For. Past. Crop Improv. Conf. pp. 21.
• Park, S., M. C. Savin, D. Philipp, K. Coffey, V. Niyigena, J. Zhao. 2019. Greenhouse gas emissions from tall fescue plots following soil surface application of excreta from ruminants fed alternative foraged-based diets. ASA-CSSA-SSSA Annual Meeting, San Antonio, TX.
• Park, S., M. C. Savin, D. Philipp, K. Coffey, V. Niyigena, J. Zhao, 2019. Alternative forage-based diets result in large, rapid soil surface ammonia emissions from tall fescue plots after receiving ruminant urine and manure ASA-CSSA-SSSA Annual Meeting, San Antonio, TX.
• Tang, Y. K., M. C. Savin, D. Philipp, K. Coffey, J. Zhao. 2019. Decomposition in pasture soil receiving excreta from ruminants fed forage diets supplemented with polyphenolic compound containing legumes. ASA-CSSA-SSSA Annual Meeting, San Antonio, TX.

Extension and Outreach

• Payne, K.M., B.M. Goff, S.R. Smith, J.H. Grove, M.S. Coyne, J.W. Lehmkuhler. 2018. Enhanced efficiency nitrogen fertilizer effect on pasture productivity. KFGC Eastern Field Day, Morehead, KY. 6 Sept.
• Payne, K.M., B.M. Goff, S.R. Smith, J.H. Grove, M.S. Coyne, J.W. Lehmkuhler. 2018. Enhanced efficiency nitrogen fertilizer effect on pasture productivity. Donald Sparks IPSS Graduate Research Symposium, Lexington, KY. 23 March.

Forage News Articles (distributed electronically and available online):

• 31 Aug 2018, Featured Publication: Forage Establishment
• 31 Aug 2018, Forage Timely Tips: September
• 31 Aug 2018, New Crimson Clover Available: Kentucky Pride
• 30 Jul 2018, Forage Timely Tips: August
• 29 March 2018, Featured Publication: Alfalfa Management Guide
• 31 Jan 2018, Frost Seeding Red and Ladino White Clover Soon
• 19 Dec 2017, Maximizing Success with Frost Seedings of Clover
• 1 Dec 2017, Don’t Trip on Triple-19