scholarly journals Seeding Rate Effects on Forage Mass and Vegetation Dynamics of Cool-Season Grass Sod Interseeded with Sorghum-Sudangrass

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2449
Author(s):  
John A. Guretzky ◽  
Daren D. Redfearn

Interseeding annual warm-season grasses into perennial cool-season grasses has the potential to increase summer forage mass and nutritive value. Knowledge of how seeding rate affects annual warm-season grass establishment, forage mass, and vegetation dynamics remains limited. From 2016–2017, we conducted a field experiment evaluating the effects of seeding rates on sorghum-sudangrass (Sorghum bicolor × S. bicolor var. sudanense) density and forage mass and on the frequency of occurrence of plant species in cool-season grass sod in Lincoln, NE. The experiment had a completely randomized design consisting of six replicates of four seeding rates [0, 14, 28, and 35 kg pure live seed (PLS) ha−1] in sod mowed at a 2.5-cm height and one unseeded, non-mowed control treatment. Sorghum-sudangrass establishment increased with seeding rate from an average of 20 to 45 plants m−2 as the seeding rate increased from 14 to 35 kg PLS ha−1. Forage mass depended on a seeding rate × harvest interaction, showing positive linear and cubic responses to seeding rate in consecutive harvests at 45 and 90 d after interseeding. To increase forage mass in perennial cool-season grass sod, producers should interseed sorghum-sudangrass with at least 28 kg PLS ha−1. One-time seedings into cool-season, perennial grass sod have no residual effects on subsequent forage mass and vegetation dynamics.

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 28-29
Author(s):  
Kelly Mercier ◽  
Chris Teutsch ◽  
Ray Smith ◽  
Eric Vanzant ◽  
Kenny Burdine ◽  
...  

Abstract The objective of this study was to determine if increasing forage botanical diversity improved stocker gains on warm-season annual (WSA) pastures. An opportunity exists to add extra gain on fall-born calves by grazing summer pastures after spring weaning and selling at a more favorable late summer market. However, cool-season perennial pastures in the Mid-South often have insufficient quality and yield to support desired summer gains. Therefore, the improved production and nutritive value of WSA forages shows promise in this system. A study was conducted near Princeton, KY, where calves (329, 366, and 297 kg in 2017, 2018, and 2019, respectively) grazed one of three WSA forage treatments without supplementation in a randomized complete block design with three replications. Treatments included 1) sorghum-sudangrass monoculture (MONO), 2) simple mixture (SIMPLE = sorghum-sudangrass, pearl millet, soybean), and 3) complex mixture (COMPLEX = SIMPLE + sudangrass, corn, crabgrass, cowpea, sunflower, sunn hemp, daikon radish, forage rape, Korean lespedeza). In 2017, MONO and SIMPLE calves had higher average daily gain (ADG) than COMPLEX calves (0.79 kg/day vs. 0.66 kg/day, P < 0.03). In 2018, no differences in ADG were detected among treatments (P > 0.3); however, calves only gained 0.01 kg/day. In 2019, MONO and SIMPLE calves again had higher ADG than COMPLEX calves (0.59 kg/day vs. 0.43 kg/day, P < 0.03). The exceptionally low 2018 ADG was likely due to the higher nutritional demand of heavier calves and the lower nutritive value of mature forages compared to other years. In conclusion, complex WSA forage mixtures did not offer any improvement in animal performance, and proper management of all WSA forages (maintaining a vegetative state) is paramount to achieving adequate gains on stockers without supplementation; however, supplementation may be necessary to improve WSA forage utilization in the rumen, potentially leading to more favorable gains.


2020 ◽  
Vol 98 (11) ◽  
Author(s):  
Prem Woli ◽  
Francis M Rouquette ◽  
Charles R Long ◽  
Luis O Tedeschi ◽  
Guillermo Scaglia

Abstract In forage-animal nutrition modeling, diet energy is estimated mainly from the forage total digestible nutrients (TDN). As digestibility trials are expensive, TDN is usually estimated using summative equations. Early summative equations assumed a fixed coefficient to compute digestible fiber using the lignin-to-neutral detergent fiber (NDF) ratio. Subsequently, a structural coefficient (φ) was added to the summative equations to reflect an association between lignin and cell wall components. Additional modifications to the summative equations assumed a constant φ value, and they have been used as a standard method by many commercial laboratories and scientists. For feeds with nutritive values that do not change much over time, a constant φ value may suffice. However, for forages with nutritive values that keep changing during the grazing season owing to changes in weather and plant maturity, a constant φ value may add a systematic bias to prediction because it is associated with the variable lignin-to-NDF ratio. In this study, we developed a model to estimate φ as a function of the day of the year by using the daily TDN values of bermudagrass [Cynodon dactylon (L.) Pers.], a popular warm-season perennial grass in the southern United States. The variable φ model was evaluated by using it in the TDN equation and comparing the estimated values with the observed ones obtained from several locations. Values of the various measures of fit used—the Willmott index (WI), the modeling efficiency (ME), R2, root mean square error (RMSE), and percent error (PE)—showed that using the variable φ vis-à-vis the constant φ improved the TDN equation significantly. The WI, ME, R2, RMSE, and PE values of 0.94, 0.80, 0.80, 2.5, and 4.7, respectively, indicated that the TDN equation with the variable φ model was able to mimic the observed values of TDN satisfactorily. Unlike the constant φ, the variable φ predicted more closely the forage nutritive value throughout the grazing season. The variable φ model may be useful to forage-beef modeling in accurately reflecting the impacts of plant maturity and weather on daily forage nutritive value and animal performance.


2011 ◽  
Vol 29 (2) ◽  
pp. 75-80
Author(s):  
Thomas Serensits ◽  
Matthew Cutulle ◽  
Jeffrey F. Derr

Abstract Cool-season grass species are often overseeded into bermudagrass turf for both aesthetics and functionality during the winter months. When the overseeded grass persists beyond the spring, however, it becomes a weed. Experiments were conducted to evaluate overseeded grass species and seeding rate on turf cover during the fall, spring, and summer. The ability of perennial ryegrass, Italian ryegrass, and hybrid bluegrass to then persist in bermudagrass one year after seeding was determined. Both perennial ryegrass and Italian ryegrass produced acceptable ground cover in the spring after fall seeding. Hybrid bluegrass did not establish well, resulting in unacceptable cover. Perennial ryegrass generally had the most persistence one year after seeding, either because of the survival of plants through the summer or because of new germination the following fall. The highest cover seen one year after seeding was 24% with perennial ryegrass in the 2005 trial. Maximum cover seen with Italian ryegrass and hybrid bluegrass 12 months after seeding was 19 and 8%, respectively. Seeding perennial or Italian ryegrass in February achieved acceptable cover in spring in the first trial but not the second. Persistence the following fall, however, was greater in the second trial, suggesting new germination. Percent cover 12 months after seeding tended to increase as the seeding rate increased, also suggesting new germination the following fall. Although quality is lower with Italian ryegrass compared to perennial ryegrass, it transitions out easier than perennial ryegrass, resulting in fewer surviving plants one year after fall seeding.


Crop Science ◽  
2009 ◽  
Vol 49 (6) ◽  
pp. 2416-2416
Author(s):  
Matt A. Sanderson ◽  
R. Howard Skinner ◽  
Martin van der Grinten ◽  
Jennifer Kujawski

2019 ◽  
Vol 3 (2) ◽  
pp. 911-926 ◽  
Author(s):  
Deidre D Harmon ◽  
Dennis W Hancock ◽  
Robert L Stewart ◽  
Jenna L Lacey ◽  
Robert W Mckee ◽  
...  

Abstract The demand for a year-round supply of fresh, locally grown, forage-finished beef products has created a need for forage-finishing strategies during the summer months in the southeast. A 3-yr study was conducted to evaluate four warm-season annual forages in a southeastern forage-finishing beef production system. Treatments were four forage species and included brown-midrib sorghum × sudangrass (Sorghum bicolor var. bicolor*bicolor var. sudanense; BMR), sorghum × sudangrass (SS), pearl millet [Pennisetum glaucum (L.) R. Br.; PM], or pearl millet planted with crabgrass [Digitaria sanguinalis (L.) Scop.; PMCG]. Treatments were distributed in a randomized complete block design with four replicates. Pastures (0.81 ha, experimental unit) were assigned to one of four forage treatments, subdivided, and rotationally stocked with a variable stocking density. British-cross beef steers (n = 32; 3-yr average: 429 ± 22 kg) grazed for 70, 63, and 56 d in 2014, 2015, and 2016, respectively. Put-and-take animals were used to maintain a forage allowance of 116 kg forage dry matter /100 kg body weight. Forage mass was measured by clipping a 4.3-m2 area in triplicate on d 0 and on 14-d intervals. Hand grab samples for forage nutritive value determination and quadrat clippings for species compositions were measured on d 0 and on 34-d intervals until termination of the trial. Forage mass was lowest (P < 0.01) for PMCG at the initiation of the grazing trial, whereas BMR was greater (P < 0.01) than SS at wk 6. Total digestible nutrients in 2014 were greater for SS compared to BMR and PM at the middle harvest (P < 0.01) and BMR, PM, and PMCG at the final harvest (P < 0.01). At the middle and final harvests in both 2015 and 2016, PM and PMCG contained greater (P < 0.01) concentrations of crude protein than SS. These results suggest that BMR, SS, PM, and PMCG may all be used in southeastern forage-finishing beef production systems, as long as the producer strategically accounts for the slight growth and nutritive value differences throughout the season.


Crop Science ◽  
2013 ◽  
Vol 53 (1) ◽  
pp. 341-348 ◽  
Author(s):  
Renata La Guardia Nave ◽  
R. Mark Sulc ◽  
David J. Barker

2014 ◽  
Vol 39 (1) ◽  
pp. 49-55
Author(s):  
Ryan L. Klimstra ◽  
Christopher E. Moorman ◽  
Sarah J. Converse ◽  
J. Andrew Royle ◽  
Craig A. Harper

2020 ◽  
Vol 36 (3) ◽  
Author(s):  
Henrique Coutinho Junqueira Franco ◽  
Bernardo Melo Montes Nogueira Borges ◽  
Sergio Gustavo Quassi de Castro ◽  
Michele Xavier Vieira Megda ◽  
Marcio Mahmoud Megda ◽  
...  

Acid reactions and low available phosphorus in tropical soils limit forage yield. The aim was to evaluate soil chemical characteristics pH, P and Mg, forage nutritive values, critical soil and plant P levels and the residual effect of each source. The experiment was in a greenhouse with a Rhodic Haplustox, loam texture. Experimental design was a 5 x 4 factorial with five replicates which phosphate fertilizers were triple superphosphate, reactive rock phosphates Gafsa and Arad, and fused magnesium phosphate powder and coarse, applied at rates of 30, 60, 90 and 120 mg kg-1 P and a control treatment without P. The effectiveness of rock phosphates increased due to their residual effect. The coarse fused magnesium phosphate resulted in the lowest efficiency. The P critical level in soil and plant were 18 mg kg-1 and 2.4 g kg-1, respectively. The increase of phosphorus rates provided an increase in crude protein content.


Weed Science ◽  
1968 ◽  
Vol 16 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Israel Feldman ◽  
M. K. McCarty ◽  
C. J. Scifres

Herbicides applied April 30, May 10, or October 14 gave best control of musk thistle (Carduus nutansL.). The most effective herbicide at all dates and rates was 4-amino-3,5,6-trichloropicolinic acid (picloram). Two lb/A of 2-methoxy-3,6-dichlorobenzoic acid (dicamba) also was effective at all spring dates. Two lb/A of 2,4-dichlorophenoxyacetic acid (2,4-D) resulted in excellent control of musk thistle when applied May 10 or October 14.More musk thistle seedlings became established in nongrazed, cool season grass pastures than in nongrazed, mixed warm season grass pastures. Greater germination was attributed to the reserve moisture and accumulation of litter which served as an excellent germination medium. However, only one musk thistle plant remained in the nongrazed pastures 1 year after seeding. The remainder of the seedlings and young rosettes found in the protected areas in 1965 had succumbed to the heavy competition by 1966.


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