Pensacola Bahiagrass Research Articles

The Effect of Split Nitrogen Applications on Nitrogen Uptake by Pensacola Bahiagrass from an Aeric Haplaquod

AbstractAn experiment was initiated with an established ‘Pensacola’ bahiagrass (Paspalum notatum Flugge) sod on Myakka fine sand (sandy, siliceous, hyperthermic Aeric Haplaquod) that had been used in a 10‐year experiment with N fertilizers. Five lime treatments were used in the previous experiment as main plots, with three N rates (0, 112, and 224 kg of N/ha/year) as subplots, and five N sources (calcium nitrate, ammonium nitrate, ammonium sulfate, urea and ureaform) as subsubplots.The current experiment was established to determine the effect of the number of N applications on N uptake efficiency in Pensacola bahiagrass forage with particular emphasis on rainfall amounts and distribution. The original experimental design was used except that treatments which had 1, 2, 4, 8, and 16 N applications/year replaced the N source variable on the sub‐subplots. Nitrogen rates were retained as in the original experiment. The experiment was conducted for 3 years.Nitrogen uptake in forage was relatively efficient ranging from 64 to 79%. There was little difference among treatments involving number of N applications. Generally, 1 or 16 applications were slightly superior to treatments involving two, four, or eight applications. Nitrate‐ and NH4+‐N concentrations in soil solutions higher than those from the control treatment were found only in March and April 1973 when initial N applications were followed by 202 mm of rainfall within a 12‐day period. This coincided with low N recovery in forage, particularly from treatments involving one or two N applications since all or one‐half of the annual N supply for these two treatments had been applied prior to this relatively intense rainfall.

Forage Yield and Percent Cell Wall Constituents of Pensacola Bahiagrass as Related to N Fertilization and Clipping Height

Abstract‘Pensacola’ bahiagrass, Paspalum notatum, Flugge, is widely grown in the Southeast but little is known about the influence that cutting height has on forage yield and forage quality. The effect of height of clipping and N fertilization rate on yield and cell wall constituents was measured over a 2‐year period on an established stand of Pensacola bahiagrass growing on a loamy sand (Psammentic paleudults) which was fertilized annually with 0, 84, 168 and 336 kg/ha of N and clipped monthly at heights of 0, 2.5, 5.0, 7.5, 10.0, and 12.5 cm above the stolons. Highest forage yields were obtained when forage was harvested at ground level and yield was least when harvested at 10.0 or 12.5 cm. Cell wall constituents of the forage ranged between 70 and 72% and were not influenced by N fertilization or clipping height. Forage from the first harvest was lower in cell wall constituents than all later harvests. The data suggest that harvesting close to the soil will increase yields but quality as measured by cell wall constituents will be largely unchanged by N application or clipping height.

Yield, Leaf Growth, and Tillering in Bahiagrass by N Rate and Season1

AbstractIf tiller numbers/area of Pensacola bahiagrass (Paspalum notatum, Flugge) could be correlated with yield and tillers/area is related to N fertility status, fertility and yield research would be simplified. To test the concept that a yield predictive model could be developed, an established Pensacola bahiagrass sod was fertilized with 0, 84, 168, and 336 kg/ha N in 1973 and 1974. Starting in early June and continuing until October plots were clipped monthly at heights of 2.5 and 7.5 cm. Before clipping, 1.0 tillers with mature leaves/plot were collected and numbers of clipped elongated and unclipped leaves were determined. Tillers on duplicate (15 cm)2 areas were counted after clipping.Dry forage was increased over the 0 N check by adding 84 and 168 kg/ha N. The 336 kg/ha N did not increase forage yields over 168 kg/ha N. Clipping at 2.5 cm produced almost three times as much forage as clipping at 7.5 cm. Number of leaves/stolon/season averaged between 20.2 and 22.0 and was influenced by N rate. At each of the five harvest dates, an average of 1.3 leaves/tiller (growing point) was elongating. Nitrogen application increased tiller numbers by up to 300% and the largest number of new tillers occurred in June. Some data as collected were predictive of N and leaf generation rate, but variations in tiller numbers/area and probably leaf weight/N relationships prevented the development of an effective yield prediction model. Further refinement of the data is needed.Statistical models based on tillers/area were not effective in predicting yields. The lack of an effective relationship between tillers/area and yield was believed due to many young tillers dying before contributing to yield and variations in leaf size reflecting N fertilization and tiller age.

Returned Clippings and N Fertilization on Bahiagrass Herbage Production and Nitrogen and Organic Matter Contents of Soil1

AbstractPlot clipping has been the time honored method of evaluating forage fertility investigations. Evidence is available suggesting that clipping data are not predictive of nutrient needs of grazed pasture. The following research was conducted with the objective to observe the effect of returning herbage to pasture at various rates of N fertilization on herbage production, N and organic matter contents of soils.A field experiment in a completely randomized split plot design, employing three replications, was conducted in 1966 and 1967 with Pensacola bahiagrass (Paspalum notatum, Flugge) grown on a Eustis loamy sand at 4 N rates. None to 100% of the harvested and dried forage was returned to the plots. Increases in forage yield due to forage return ranged from non‐significant when no N was applied to considerable increases as indicated by the steeper regressions as N application increased. Over the 2 years, application of 84 kg/N/ha together with returning the forage produced as much forage as 168 kg/N/ha in combination with removing it.Returning the forage had minor influence on soil N and organic matter contents. Evidence obtained suggested that mineralization and availability of recycled nutrients to a sward is probably a long‐term affair when available N is low. N applications appeared to appreciably shorten the length of time required for returned forage to offer advantage to the sward. The evidence presented indicated that both high forage yields and maximum improvement of soil fertility in the Eustis soil could be achieved when 40 to 60% of the bahiagrass herbage were returned to the pasture accompanied by large application of N fertilizers.

Evaluation of Annual Grass Forages in Prepared Seedbeds and Overseeded into Perennial Sods

Four adjoining 8-acre (3.24 ha) plots were each divided into 2-acre (.81 ha) subplots and planted to either Pensacola bahiagrass, Coastal bermudagrass, Coastcross-1 bermudagrass or left fallow to be planted in summer and winter annual grasses. Ryegrass or oats were overseeded into perennial sods and into prepared seedbeds for winter grazing. Gahi millet or a sorghum × sudan hybrid was seeded into the prepared seedbeds and compared with the three perennial grasses for summer grazing. During the winter phase (December to April), steers which grazed either oats or ryegrass in prepared seedbeds gained 2.30 lb (1.05 kg) per day and produced total live weight gains of 453 lb/acre (504 kg/ha) compared with 2.47 lb (1.12 kg) per day and 222 lb/acre (253 kg/ha) for similar steers on sod-seeded pastures. During the summer phase (April to October), steers which grazed Gahi millet gained 2.13 lb (.97 kg) per day and produced total live weight gains of 467 lb/acre (525 kg/ha) compared with 1.95 lb (.89 kg) per day and 334 lb/acre (376 kg/ha) for the sorghum × sudan summer annual. In contrast, average daily gains and total live weight gains per acre (hectare) for the perennial sods were: Pensacola bahiagrass, 1.26 lb (.57 kg) and 441 lb (493 kg); Coastal bermudagrass 1.41 lb (.64 kg) and 494 lb (553 kg); Coastcross-1 bermudagrass 1.58 lb (.72 kg) and 531 lb (598 kg).

Recurrent Restricted Phenotypic Selection Increases Forage Yields of Pensacola Bahiagrass1

Recurrent restricted phenotypic selection (RRPS), modified form of mass selection, was evaluated as a breeding technique for improving the forage yield of Pensacola bahiagrass (Paspalum notatum var. saure ‘Parodi’), a sexual diploid. Selection was based on single green weights of spaced plants at the end of the first season and spring yield the following year. Four cycles of RRPS increased forage yield of this grass 17.7% over that of the commercial check. The rate of progress per 2‐year cycle in a previously selected narrow‐gene population (NGP) was about 2%/cycle. In an unselected wide‐gene population (WGP), rate of progress was 6%/cycle. Variances and coefficients of variability (CV's) for yield spaced plants of the original and fourth‐cycle populations compared in the same test were similar for the NGP but were reduced substantially to the NGP level in the WGP. RRPS increased the frequency and yield of high‐yielding plants. Increasing seeding rates from 3 to 27 kg/ha in methyl bromide treated soil increased firstyear forage yields 76%, but had no effect on the relative yields of the commercial check and the fourth‐cycle populations. The data suggest that rate of progress could be doubled by use of a 1‐year cycle and the saving of 3 to 4 rather than 5 of the best plants in each 25‐plant block.

Response of Pensacola Bahiagrass to Irrigation and Time of N. Fertilization

Response of Pensacola Bahiagrass to Irrigation and Time of N. Fertilization

Comparative Degradation of Coastal Bermudagrass, Coastcross‐1 Bermudagrass, and Pensacola Bahiagrass by Rumen Microorganisms Revealed by Scanning Electron Microscopy1

Leaves of the cultivars Coastal bermudagrass and Coastcross‐1 bermudagrass (Cynodon dactylon (L.) Pets.) and Pensacola bahiagrass (Paspalum notatum var. saurae Parodi) were investigated to delineate the relationship between microanatomy and rumen microbial degradation. Leaf sections of each forage were incubated in vitro with rumen microorganisms for 6, 12, and 72 hours and examined for the ease and extent of tissue degradation using a scanning electron microscope. Tissues of Coastcross‐1 bermudagrass were degraded faster than comparable tissues of Coastal bermudagrass. The extent of degradation after 72 hours appeared to be equal in the bermudagrasses. The rate of total tissue degradation in bahiagrass appeared to be between that of the bermudagrass cultivars. Results indicated that microanatomy effected differences in rumen microbial degradation between the two forage species. However, the rate of degradation between the cultivars of bermudagrass appeared to be due to inherent differences in the cell wall organization or composition of degradable tissues. Improvement in the digestibility of these forages may be possible by plant breeding to reduce microanatomical obstructions to digestibility or by breeding or processing techniques to modify structural limitations to digestibility in the cell walls.

Coastcross-1 Bermudagrass, Coastal Bermudagrass and Pensacola Bahiagrass as Summer Pasture for Steers

Three 2-acre (.81 ha) pastures of Pensacola bahiagrass, Coastal bermudagrass and Coastcross-1 bermudagrass were grazed during a 4-year period by yearling beef steers. During all 4 years, the average daily gains of steers grazing Coastcross-1 bermudagrass were superior (P<.05) to gains made by steers grazing Pensacola bahiagrass or Coastal bermudagrass. The mean average daily gains were 0.95, 1.08 and 1.50 lb. (0.43, 0.49 and 0.68 kg) per day for Pensacola bahiagrass, Coastal bermudagrass and Coastcross-1 bermudagrass and resulted in calculated average beef production per acre (hectare) values of 222, 331 and 469 lb. (249, 372 and 527 kg) per year for the three grasses. The average dry matter yield from Coastal bermudagrass pastures was about 35% greater than dry matter yields from either Pensacola bahiagrass or Coastcross-1 bermudagrass pastures. Periodic average daily gain and in vitro dry matter digestibility time trends were related (P<.05).

Nutritive Value of Pensacola Bahiagrass Stolons1

AbstractForage shortage and low forage quality during the winter season are critical in Florida during some years. Pensacola bahiagrass (Paspalum notatum Flugge) produces massive stolon‐root systems with relatively high crude protein concentrations if adequate nutrients are supplied. Preliminary in vitro digestion studies with these stolons indicated high digestibility. An experiment was initiated to study the feed value of this material and to determine the feasibility of using it during critical winter periods. Stolon evaluation was made by chemical analyses and by feeding trials with sheep to determine voluntary intake and nutrient digestibilities. Chopped stolons were mixed with chopped bahiagrass hay to give variable hay:stolon ratios. Each ration was supplemented with 10% molasses and 10% soybean meal. Dry matter and crude protein contents for all rations were approximately 86 and 12.5%, respectively. No difference was found in intake of organic matter or digestible organic matter among treatments. Cellulose digestibility decreased as the proportion of stolons in the rations was increased, but crude protein digestibility increased. Animals on all treatments averaged gains in excess of 5 kg during the 21‐day period. The chopped stolons were not readily accepted by sheep, but the addition of molasses and soybean meal markedly improved palatability. Cattle withheld from feed for 2 days consumed the stolons satisfactorily.

Role of Pensacola Bahiagrass Stolon‐Root System in Fertilizer Nitrogen Utilization on Leon Fine Sand1

AbstractAn experiment was conducted with Pensacola bahiagrass (Paspalum notatum Flugge) on Leon fine sand near Gainesville, Fla. for 6 years to determine residual effects of applied N on forage N uptake, and changes in stolons, roots, and soil N. Nitrogen was applied at 0, 112, 224, and 448 kg/ha/year. Except for the control, paired plots were used at each N rate. Nitrogen fertilization was dis. continued on one of each treatment pairs in 1969 and 1970 to determine the residual effect of N. These treatments were resumed in I971. The residual effect of N was small for all treatments, amounting to 8, 41, and 95 kg/ha total N in harvested forage above the control for the 2‐year period for the 112, 224, and 448 kg N rates, respectively. Unrecovered N through 1968 was approximately 200, 350, and 770 kg/ha for the three treatments, respectively. Nitrogen lost from the stolon root systems during 1969 and 1970 through decrease in mass and N concentrations was 60, 100, and 190 kg/ha for the three N treatments, respectively. Little of the unrecovered N could be accounted for by analysis of the surface soil. Lack of residual effect on plant growth confirmed that little available N was in the soil profile to rooting depth. Based on previous studies, leaching appears to have limited importance when N is applied to well‐established perennial grass pastures during the growing season. Conditions imposed in this soil by high water table, large amounts of plant residues, and rapid decomposition during the summer season could make denitrification a significant factor.

Interaction of Nematodes and Soil Temperature on Growth of Three Tropical Grasses1

AbstractYields of several pasture grasses in Florida are seriously reduced by nematodes. This study investigated the relation between soil temperature and growth of grasses.Three tropical grasses were planted in soil infested with parasitic nematodes and were grown under greenhouse conditions at eight temperature levels. These temperature levels were established in a water‐bath consisting of an insulated, copper‐lined, wooden tank equipped with electrical heating and cooling controls.Soil temperatures influenced the amount of plant injury from parasitic nematodes, but the degree of such injury was dependent on the type of nematode present and on the susceptibility of the host plant.Sting nematodes (Belonolaimus longicaudatus Rau) were most active at soil temperatures between 20 and 34 C. Pensacola bahiagrass (Paspalum notatum Flugge) and limpograss [Hemarthria altissima (Poir) Stapf et C. E. Hubb P.I. 299994] produced greatest forage yields when soil temperatures were between 34 and 38 C. At the temperatures tested above 38 C, sting nematodes were greatly reduced, but ring nematode (Criconemoides spp. Taylor) populations were maintained. Forage yields of pangola digitgrass (Digitaria decumbens Stent) were highest when grown at temperatures between 38 and 41 C.

Humic‐Fulvic Acid Content in Soils as Related to Ley Clipping Management and Fertilization

AbstractStudies on changes of humic‐fulvic acid content in a Eustis loamy sand due to weekly clipped Pensacola bahiagrass (Paspalum notatum Parodi) and fertilization showed that nitrogen fertilization encouraged formation of humic acid and decreased fulvic acid contents in soils. Longer clipping intervals tended to increase the amount of both humic and fulvic acid when nitrogen fertilization was applied.A significant positive correlation between nitrogen or organic‐P contents of the soil and humic/fulvic acid ratios indicated that humic‐fulvic acid formation was affected by soil nitrogen content (or organic‐P). A correlation also existed between humic‐fulvic acid and pH, in which a decrease of soil pH resulted in an increase of humic/fulvic acid ratio.

Performance of Steers on Pensacola Bahiagrass, Coastal Bermudagrass and Coastcross-1 Bermudagrass Pastures and Pellets

Performance of Steers on Pensacola Bahiagrass, Coastal Bermudagrass and Coastcross-1 Bermudagrass Pastures and Pellets

Organic Matter, N, and Base Accumulation under Pensacola Bahiagrass

A deep and unfertile sandy soil sin the Georgia Coastal Plain from which the top soil had been removed was seeded to Pensacola bahiagrass in 1967 and allowed to grow until 1970. No harvests were made, and no fertilizer was applied. When sampled in 1970, the plots under grass contained 23.1% more N than did fallow plots. The soil organic matter content to 12 inches deep in the soil profile had more than doubled under the sod, and bases had been accumulated in the soil surface under sod but were concentrated lower in the soil profile under fallow.

Forage Characteristics Limiting Animal Performance on Warm‐season Perennial Grasses1

AbstractChemical and in vitro characteristics of six perennial summer grasses {common, ‘Coastal’ and ‘Coastcross‐1’ bermudagrasses [Cynodon dactylon (L.) Pers.]; ‘Pensacola’ bahiagrass [Paspalum notatum Flugge]; common weeping lovegrass [Eragrostis curvula (Schrad.) Nees.]; and ‘Kleingrass 75’ [Panicum coloratum L.]} were determined to identify factors limiting the performance of grazing animals. In vitro dry‐matter digestibility (IVDMD), cell wall content (CWC), acid‐detergent fiber (ADF), acid‐detergent lignin (ADL), silica, and in vitro cell‐wall digestibility (IVCWD) were determined for samples of available forage taken at 14‐day intervals. Animal performance was obtained from yearling heifers grazing established stands of each grass. Available forage was estimated from strips harvested from each pasture at 2‐ to 4‐week intervals. Animal performance was significantly correlated (r = 0.85**) with available forage when dry‐matter digestibility was relatively uniform. As IVDMD of available forage decreased, more available forage was required to reach maximum average daily gain (ADG). Also, as IVDMD decreased, maximum ADG decreased. The CWC of the grasses ranged from 45 to 82% with cell wall digestibility ranging from 82 to 36%, respectively. CWC and IVDMD were significantly correlated with animal performance (r = —0.80**, and 0.78**, respectively). Cell wall digestibility calculated from Van Soest's “summative equation” significantly over‐estimated IVCWD. Lignification was one factor limiting cell wall digestibility (r = —0.76**) and in Coastcross‐1 bermudagrass and Pensacola bahiagrass silica was as important as lignin. CWC and IVCWD could be used to accurately predict IVDMD in Kleingrass 75 (r = —0.96** and 0.95** respectively). High lignin and/or silica content of available forage was associated with poor animal perfortnance on all grasses.

Comparative feeding value of pelleted Pensacola bahiagrass, coastal bermudagrass and coast-cross-1 bermudagrass harvested at four and eight weeks of age.

Comparative feeding value of pelleted Pensacola bahiagrass, coastal bermudagrass and coast-cross-1 bermudagrass harvested at four and eight weeks of age.

Regression of Nitrogen Uptake on Nitrogen Added from Four Sources Applied to Grass1

AbstractResearch was conducted to evaluate efficiencies of N fertilizers by comparing slopes of N uptake on N applied regression equations. Ammonium nitrate (33.5‐0‐0), diammonium phosphate (21‐23‐0), urea (45‐0‐0), and ureaammonium phosphate (33‐9‐0) were surface applied at four rates of N to Coastal bermudagrass on Norfolk sandy loam and to Pensacola bahiagrass on Boswell fine sandy loam. Relative efficiencies for N recovery were determined by comparison of the slopes (b) of the equations. The highest average efficiency (b = 0.80) was obtained with ammonium nitrate on bermudagrass. Values of b were similar for all sources of N on bahiagrass. There was a straight line relationship when dry forage produced (y) was plotted against N uptake (x). The equations were y = 1,500 ‐f 48x and y = 3,000 ‐j‐ 34x for bahiagrass and bermudagrass, respectively. These differences in slopes of the equations reflect the differences both in N contents and yields of the forage.

Soil Organic Matter Content and Composition as Related to Ley Clipping Management and Fertilization

AbstractSoil organic matter content' and composition, with particular attention to C/Porg and C/N relationship, were investigated under clipping and fertility treatments applied to Pensacola bahiagrass (Paspalum notatum, Flugge) grown on a Eustis loamy sand.The results indicated that soil organic matter accumulation was influenced by the interaction of nitrogen fertilization and clipping management. Nitrogen fertilization alone had some effect, whereas clipping only had no influence on the organic C content of the surface soil. The C/N ratio decreased with depth in the profile with weekly clipping, but remained relatively constant from the surface to 30–40 cm depth with monthly clipping intervals.The C/Porg ratio in the surface soil increased with increasing N‐fertilization as well as by monthly and 6‐weeks clippings. The effect of interaction of N‐fertilization and clipping frequency on the C/Porg ratio was greater than the influence of clipping frequency or N‐fertilization alone. The C/Porg ratio of the subsoil was unaffected by either.

Effect of Ploidy on Fertility and Heterosis in Pensacola Bahiagrass1

Diploid and tetraploid sectors isolated from seven mixoploid plants derived from Pensacola bahiagrass, Paspalum notatum var. saurae Parodi, seed treated with colchicine were selected to study the effect of ploidy on seed set and heterosis. Doubling the chromosome number did not improve the self‐fertility of the highly self‐incompatible diploid clones. Diploids set seed equally well in diploid or in diploid‐tetraploid polycrosses but tetraploids that set seed well in tetraploid polycrosses set less than half as much seed in etraploid‐diploid polycrosses. Single‐head diploid ✕ diploid and tetraploid ✕ tetraploid matings set nine and four times more seed, respectively, than diploid ✕ tetraploid or tetraploid ✕ diploid matings. Tetraploid ✕ tetraploid hybrids generally yielded less forage than diploid ✕ diploid hybrids involving the same genotypes. Otherwise, ploidy had little, if any, effect on the expression of heterosis.