Cool Season Perennial Grass and Grass-Clover Management CIRCULAR 175 APRIL 1970 ~ii Agricultural Experiment Station Auburn, Alabama AUBURN E. V. Smith, Director UN IVERSITY CONTENTS Page GENERAL PROCEDURES_ IRRIGATION OF CRASS-CLOVER MIXTURES AT TENNESSEE VALLEY SUBSTATION-------4 7 R esu lts -- - - - - - - - - - - - - - - - -- - - - - - - - - Conclusions-----------------------IRRIGATION, STUBBLE HEIGHT, AND CUTTING FREQUENCY ON CRASS-CLOVER MIXTURES AT DAIRY RESEARCH U NIT, AUBURN -- --- - - - - - - - - - - - - - - - - - - Res ults - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - 10o C onclu sion s - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - -.12 NITROGEN FERTILIZATION OF GRASS-LEGUME THE PIEDMONT SUBSTATION--MIXTURES AT --- .12 Res u lts - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 12 C on clu sio n s - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - -_14 EFFECT OF CUTTING FREQUENCY ON PRODUCTIVITY AND~ PERSISTENCE OF CLOVER IN GRASS AT ALEXANDRIA EXPERIM ENT FIELD--------------------------------- _14 Res u lts - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - -15 Co n clusio n s - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - - - - - _16 SUMMER MANAGEMENT STUDIES ON TALL FESCUE, HARDING, AND KOLEAGRASS AT PLANT BREEDING UNIT------------- 17 Res u lts - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -17 Co n clu sion s - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - -_20 S UM M A R Y - - - - - - - - - - - - - - - - - - -- - - - - - - - - - - - - - - - - - - - - - - - 20 ACKNOWLEDGMENT- _21 FIRST PRINTING 3M, APRIL 1970 Cool Season Perennial Grass and Grass-Clover Management C. S. HOVELAND, Prof. of Agronomy ond Soils E. M. EVANS, Assoc. Prof. of Agronomy and Soils COOL SEASON PERENNIAL grasses are commonly used in Ala- bama to furnish grazing for beef brood cow herds in winter and spring. Tall fescue, the most widely planted cool season perennial grass, is adapted to certain soils over the entire State.' Orchardgrass is best adapted to well-drained northern Alabama soils having good moisture relations and fertility. Legumes, mainly ladino or intermediate white clovers, are often planted with these grasses to improve forage quality and supply some of the nitrogen requirement of the grass. The summer climate in Alabama differs considerably from that of the major cool season perennial grass areas farther north. The high summer temperature, combined with alternating periods of drought or excessively high rainfall, place considerable stress on these grasses and associated legumes. In central and southern Alabama, tall fescue often becomes semi-dormant and makes little growth in summer. Several parasitic disease organisms, primarily fungi, may also be a problem. Forage yields of these cool season perennial grass species are often low during the October to March period. On many farms grass stands thin after a few years and clover stands commonly persist only 1 to 2 years in grass-clover mixtures. This publication summarizes research in Alabama on some factors that affect yield and stand persistence of cool season perennial grasses and legumes. In these experiments at five locations in the State, irrigation, nitrogen fertilization, frequency of cutting, stubble height, and seasonal resting were studied. Hoveland, C. S., E. M. Evans, and D. A. Mays. 1969. Cool season perennial grass species for forage in Alabama. Auburn Univ. (Ala.) Agr. Exp. Sta. Bull. 397. GENERAL PROCEDURES In each experiment 5 x 20-foot plots, replicated four times, were clipped at 4 to 8-week intervals unless otherwise specified. Harvesting was by means of a sicklebar mower or a flail harvester at a height of 3 inches. Forage yields are expressed on the basis of oven dry forage per acre. All yield data were analyzed and only differences significant at P<.05 were considered real differences. Lime, phosphorus, and potassium were applied according to soil test. Nitrogen rates are noted for each experiment. Botanical composition estimates were made prior to each harvest. Several samples were separated by hand to check the accuracy of the estimates. IRRIGATION OF GRASS-CLOVER MIXTURES AT TENNESSEE VALLEY SUBSTATION Experiments were conducted for 3 years on Dewey clay loam, a red soil with good water holding capacity, and Humphries silt loam, a gray soil generally considered to be more droughty because it is underlain by cherty gravel. Grasses and legumes were planted the fall of 1955, the grass in 12-inch rows and the legume broadcast. Two inches of water was applied by sprinkler irrigation whenever a 2-inch net loss of water occurred by evaporation from an open pan. Results Irrigation did not significantly increase total forage yield on either soil when all species were considered. Tall fescue, smooth brome, and orchardgrass showed little or no total yield response to irrigation on either soil, Tables 1 and 2. In contrast, Kentucky bluegrass yields were increased about 50 per cent on both soils by irrigation. Reed canarygrass yields were increased 80 per cent on Dewey clay loam by additional water. However, both of these grasses were considerably less productive than tall fescue on Humphries silt loam. Orchardgrass-ladino clover yield response to irrigation was 44 per cent on Dewey clay loam and 24 per cent on Humphries silt loam. Even so, the total yield was well below that of orchardgrass fertilized with nitrogen. Tall fescue-ladino clover response to irrigation was less than orchard-ladino on Dewey clay loam. On the Humphries soil, irrigation had no effect on yield of tall fescue-ladino. [4] TABLE 1. EFFECT OF IRRIGATION ON LATE WINTER-EARLY SPRING AND TOTAL FORAGE YIELD OF COOL SEASON PERENNIAL GRASSES AND GRASS-LEGUME MIXTURES ON DEWEY CLAY LOAM, TENNESSEE VALLEY SUBSTATION, 1956-581 Species March-mid-April production Effect of N/A/yr.Oven dry forage per acre irrig. on Not irrig. UI: Irrig. V yield Y Total annual production Oven dry forage per acre Irrig. Effect of irrig. on Not irrig. ~IVI~ yield Ilrr Lb. ---.-------Ky. 31 tall fescue Commer. orchardgr.--------Auh. reed canarygr. _-----,-Ky. hluegrass-------- ---- -Southland sm. hromegr.----- Lb. 2,100 2,090 2,370 1,590 1,950 1,440 1,230 1,500 1,060 550 1,120 710 Lb.. 3,190 2,440 2,600 1,100 Pct. -34 -14 - 9 44 -14 -15 2 -15 - 4 -610 -22 -41 Lb. 8, 000 7,220 8,340 6,340 6,160 4,900 5,400 4,660 2,980 2,780, 4, 500 2,400 Lb. 7,320 6,480 6,400 4,020 6,420 4,060 3,760 4,480 3,040 3,840 4,320 3,060 Pct. 9 11 30; 58 - 4 21 44 4 - 2 -28 4 -22 160 160 160 160 160 0 0 0 0 0 0 0 2,270 1,690 1,210 1,770 1,100 1,370 1,430 1,200 Ky. 31 tall fescue & ladino clov er - - - - -- - -- - - - - - - - -Orchardgrass & ladino cloverReed canary & ladino Ky. hluegrass 1 clover-- & ladino clover- Orchardgrass & alfalfa-_---. Reed canary & alfalfa------- Smooth hrome & alfalfa----- April through August rainfall for 1956, 1957, and 1958 was 19.5, 13.9, and 24.2 inches, respectively. Irrigation water applied for the 3 years was 10, 10, and 16 inches, respectively. TABLE 2. EFFECT OF IRRIGATION ON LATE WINTER-EARLY SPRING AND TOTAL FORAGE YIELD OF COOL SEASON PERENNIAL GRASSES AND GRASS-LEGUME MIXTURES ON HUMPHRIES SILT LOAM, TENNESSEE VALLEY SUBSTATION, 1956-58' March-mid-April production Species N/A/yr. Oven dry forage per acre Not irrig. Lb. 3,460-18 2,380 1,490 1,340 2,140 2,050 Total annual production Oven dry forage per acre Irrig. Lb. 7,840 5,060 5,600 Irrig. Lb. Lb. Ky. 31 tall fescue_________________________ 160 2,840 Commer. orchardgr.___------------------160 1,680 Aub. reed canarygr,---------------------160 1,600 Ky. bluegrass____ 160 1,420 Southland sm. bromegr.-------160 0 Effect of irrig. on yield Pct. -29 7 Not irrig. Lb. 8,040-3 5,400 4,780 Effect of irrig. on yield Pct. - 6 17 6 -49 4,700 4,120 4,600 3,260 4,880 4,760 44 -16 3 1,100 1,340 Ky. 31 tall fescue & ladino Orchardgrass & ladino clover---. Reed canary & ladino clover----Ky. bluegrass & ladino clover---Orchardgrass & alfalfa_________ Reed canary & clover---------------------- -35 - 0 0 0 0 0 910 990 920 730 720 1,190 1,290 1,160 1,290 1,060 -24 -23 -21 -43 -32 4,000 3,740 .3,700 3,740 3,520 3,220 3,380 2,960 3,880 4,000 - 24 11 25 4 -12 Smooth brome & alfalfa _______ 0 810 1,170 -31 2,480 3,540 -30 1 April through August rainfall for 1956, 1957, and 1958 was 19.5, 13.9, and 24.2 inches, respectively. Irrigation water applied for the 3 years was 10, 10, and 14 inches, respectively. alfalfa ---------- Tall fescue, reed canary, orchard, and brome were the highest yielding grasses. Ladino clover-grass mixtures were generally more productive than those containing alfalfa. The most productive mixture on Humphries silt loam was Kentucky 31 tall fescue and ladino clover. Irrigation generally reduced early season forage production of most grasses and grass-legume mixtures, Tables 1 and 2. Kentucky bluegrass was an exception in showing a 44 per cent increase in early season growth on irrigated Dewey clay loam; however, production was quite low. Crabgrass competition was stimulated by irrigation, reducing stands and vigor of most cool season forage species. Ladino clover stands persisted much better with all grasses on Dewey clay loam than on the more droughty Humphries silt loam, Figures 1 and 2. By the third year, ladino clover made up only 10 to 17 per cent of the total forage in mixtures with tall fescue or orchardgrass on Humphries silt loam. Ladino clover stands persisted well in orchardgrass on Dewey clay loam the fourth year, Figure 3. Irrigation reduced ladino clover persistence in all grasses on Humphries silt loam, Figures 1 and 2. On Dewey clay loam, ladino clover was reduced by irrigation in all grasses except Kentucky bluegrass. Alfalfa stands were good the first year on both soils. However, by the end of the second harvest year stands had disappeared on Humphries silt loam. On Dewey clay loam, alfalfa stands were severely depleted by the third year. On both soils, alfalfa contributed little forage in any mixture the third year, Figures 1 and 2. Irrigation accelerated this trend. Conclusions Spring and summer irrigation did not increase total forage production appreciably in the Tennessee Valley area on either soil during any of the 3 years. Instead, winter and early spring forage yields were generally depressed. Severe summer weed competition under irrigation sharply decreased clover stands and virtually eliminated alfalfa. The most productive grasses were Kentucky 31 tall fescue, Auburn reed canary, orchard, and Southland brome. The most productive mixtures on Dewey clay loam were those including ladino clover. On Humphries silt loam the most productive mixture was Kentucky 31 tall fescue and ladino clover. Grasses [7] Legume oo 1956 100 - I L 1957 S 1958 80 60 40 20 0----------- o O100 Bluegrass- Orchardladino Legume ladino Reed canary- Tall fescueladino ladino Bromegrassalfalfa Orchardalfalfa Reed canaryalfalfa Irrigated 3rcha7-7 ladi// Bluegrassladino Orchardladino Reed canary- Tall fescueladino laodino Bromegrassalfalfa Orchardalfalfa 1I Reed canaryalfalfa FIG. 1. Legume percentage in cool season perennial grass forage during May on Dewey clay loam at Tennessee Valley Substation. fertilized with 160 pounds of nitrogen per acre generally made more late winter and annual production than grass-legume mixtures. [8] Legume 80% 80oFr 1956 Not irrigated 1957 1958 60- 4.0 20 n Bluegrass- Legume ladino OrchardaIodino Reed canary- Tall fescueladino ladino Bromegrassalfalfa Orchardalfalfa Reed canaryalfalfa 80- Irrigated 60 - 40- 120i /0 /z i iKLA Ir_.,. -- Bluegrassladino Orchardlodino Reed canaryladino Tall fescueladino Bromegrassalfalfoa Orchardalfalfa Reed canaryalfalfa FIG. 2. Legume percentage in cool season perennial grass forage during May on Humphries silt loam at Tennessee Valley Substation. IRRIGATION, STUBBLE HEIGHT, AND CUTTING FREQUENCY ON GRASS-CLOVER MIXTURES AT DAIRY RESEARCH UNIT, AUBURN Three grasses and six grass-legume mixtures were studied for 3 years under four systems of cutting and two levels of moisture on Appling sandy loam at the Dairy Research Unit, Auburn, Alabama. Grasses and legumes were band seeded the fall of 1955 and the following harvesting treatments were started in [9] FIG. 3 Ladmno clover in non-irrigated orch~ardgrass on Dewey nessee Volley Substation, 4th year. cloy loom at Ten- 1956: ( a ) ci t at '3-inches ex ('i 6 wee(ks 1from1 Septembiler to iun e; (1)) cut at 1'i _ ii ches ev erx 6 we eks from September to Junle: (c ) cut at P. .' ii ches cx ery 14 da\ s from SepteilIcr to Jiunc; and (1d) cuti at 1 P inches ce erx 14 (laxys all xcar. N atuiral rainfall andl irrigatioi I l) pcrforated pipe prox idcd~ the two lex (,Is of soil Iri*igatedi plots we re wx ateredl to field capacit wben( mnoisturei(. soil imoistiureP declii ed to less than 50) per ccint of the ax ailable wxater holdliig capacity as determnied bx soil saimpliiig. Results 'tields of glasses fertil ized xwi th n~itrogen wx(re higher thai grass-lcguii c ixituIres, Tale ). Aliso, grass-I eglui c mixtures made less xWiiinter andl earlx springI groxvth thai grass fertilized xxvith initroigei. Forage vfieldls xxere collsidleral)lx loxxer at this location thIai at the leni itsse Val lex Siub station , Tahbles 1, , and r3. Cl.iimatic coinditions wer dc ohoahlx- less lax oralhle for. ccol season pereni al sp~ecies in cen]trad thai in northiern Alabama. Tall fescue ai d( reedl canarx grass xx'ce geierall \ more pro(luctix c thai orchardgrass. Tall fescue xas especiallx resistanit to xx ed eincroachmnit andl orchardgrass ,xvas the poorest in this [ 10) 1 TABLE 3. OF IRRIGATION, STUBBLE HEIGHT, AND FREQUENCY OF CLIPPING ON FORAGE YIELD OF COOL SEASON PERENNIAL GRASSES AND GRASS-LEGUME MIXTURES AT DAIRY RESEARCH UNIT, AUBURN, ALABAMA, 1956-58 EFFECT Species Irrigation' Dry forage per acre Clipped Clipped Clipped Clipped at 3 in. at1/in.at12in.at1in every every every 6 wks. 6 wks. 2 wks. 2 wks. Sept.Sept.Sept.- all year june June June every Lb. Lb. Ky. 31 tall fescue 2 Lb. 4,930 5,790 3,320 3,500 4,710 4,660 4,320 4,650 2,640 3,900 2,420 2,820 3,240 4,200 2,770 3,640 2,080 2,260 1,700 1,885 2,120 2,600 Lb. 2,60 4,080 2,770 2,640 2,550 2,590 2,660 3,100 1,660 2,910 2,120 3,340 1,880 2,460 1,890 2,900 860 1,810 1,440 1,500 1,350 1,440 Ky. 31 tall fescue 2 Commercial orchardgrass' Commercial orchardgrass' Auburn reed canarygrass' Auburn reed canarygrassAverage -- -- -- - -- -- Tall fescue-ladino Tall fescue-ladino 3 None __ Irrig. None __ Irrig. None Irrig. None -- - - Irrig. None Irrig. None Irrig. None Irrig. None Irrig. None Irrig. 3,440 4,340 3,000 2,380 4,160 3,710 3,530 3,480 1,920 2,500 1,580 1,610 1,910 2,340 1,800 2,150 1,320 1,230 1,190 1,290 1,620 1,560 3,490 4,700 2,800 3,530 3,660 4,590 3,320 4,270 2,130 3,950 2,030 3,270 1,870 4,050 2,010 2,760 1,190 2,140 1,440 1,720 1,550 2,260 Orchard-ladino clover'---------Orchard-ladino clover'---------Reed canary-ladino clover'-----Reed canary-ladino clover'-----Average ------------------- - --Tall clover clover'-------- fescue-alfalfa'-------------fescue-alfalfa'-------------canary-alfalfa'------------- Tall Orchard-alfalfa'---------------Orchard-alf alf a'----------,----Reed None Irrig. None Irrig. Reed canary-alfalfa'-----------Average--------------- ---- 1,220 1,970 1,390 1,380 1,580 2,250 2,040 1,360 1'Irrigation water applied May to September, 1956, 1957, and 1958 was 7.5, 12.0, and 12.0 inches, respectively. 2Received 200 lb. N/A annually. --*None Irrig. 'No N applied. respect. Orchardgrass produced substantial yields during spring while tall fescue was productive over much of the year. Reed canarygrass made little growth in early spring but was quite productive in summer if adequate moisture was provided. Clipping at 11/2 inches every 2 weeks all year, to simulate continuous hard grazing, generally resulted in the lowest forage yields, poorest legume stands, and most weeds. This treatment resulted in significantly lower yields of grass alone than when harvested every 2 weeks from September to June. Highest yields of tall fescue and reed canary were usually obtained when clipped at 112 inches every 6 weeks from September to June. Orchard[ ii ] grass responded similarly the first year but in succeeding years production on all treatments was similar and low. There was no advantage for any species in leaving a 3-inch as compared to a 11/2-inch stubble as yields were highest on the latter treatment. Irrigation increased forage yields of tall fescue fertilized with nitrogen 17 per cent and tall fescue-ladino clover 47 per cent when both were clipped at 11/ inches every 6 weeks from September to June. Grass-clover mixtures were generally more responsive to irrigation than grass alone. However, it is unlikely that the value of increased forage would pay for the cost of irrigation. Reed canary and orchardgrass gave little or no response to irrigation. Weeds, mainly crabgrass (Digitaria sanguinalis) and annual fleabane (Erigeron annuus) increased with irrigation, particularly under frequent cutting. Alfalfa stands persisted only 2 years, regardless of clipping treatment or irrigation. Ladino clover persisted better than alfalfa and maintained better stands in combination with orchardgrass and reed canarygrass than with tall fescue. However, in a pasture it is likely that the low palatability of reed canarygrass would result in selective grazing of ladino clover and eventual loss of clover stands. Conclusions Irrigation of cool season perennial grasses in central Alabama during summer resulted in only a modest increase in forage yield but caused heavy growth of summer weeds, particularly under frequent clipping. Results of this experiment indicate the importance of "resting" or not grazing cool season perennial grasses during summer. Grasses fertilized with nitrogen made higher winter-early spring and total production than grass-legume mixtures. NITROGEN FERTILIZATION OF GRASS-LEGUME MIXTURES AT THE PIEDMONT SUBSTATION Nine cool season grasses and grass-legume mixtures were band seeded the fall of 1955 on Lloyd clay at the Piedmont Substation. Each species was fertilized with 0 or 150 pounds nitrogen per acre applied in four applications. Plots were clipped monthly throughout the year. Results Tall fescue was more productive than orchard, reed canary, or Kentucky bluegrass, Table 4. Nitrogen application generally [12] tripled forage yields over that of grass with no nitrogen fertilizer. The sharp declines in yields the third year were probably a result of monthly clipping throughout the summer, suggesting the need for a summer rest period. Alfalfa in combination with tall fescue, reed canary, or orchardgrass with no nitrogen fertilizer was quite productive the first 2 years and yields generally equalled or exceeded the grasses alone with 150 pounds of nitrogen per acre. Nitrogen did not affect stands of alfalfa. However, the third year alfalfa stands virtually disappeared, probably a result of the severe monthly cutting treatment. Ladino clover-grass mixtures were less productive but persisted longer than alfalfa-grass mixtures. Nitrogen fertilizer decreased stands of ladino clover, particularly in tall fescue. Although yields were low the third year, ladino clover-grass mixtures were more productive than the grasses with 150 pounds of nitrogen per acre. Late winter-early spring (February to mid-April) production of grass-clover mixtures was low without nitrogen fertilizer, Figure 4. Grasses alone made virtually no growth during this period without nitrogen. When fertilized with nitrogen, tall fescue, tall TABLE 4. EFFECT OF NITROGEN FERTILIZER ON FORAGE YIELD OF COOL SEASON PERENNIAL GRASSES AND GRASS-LEGUME MIXTURES AT PIEDMONT SUBSTATION, 1956-58 Nitrogen per acre Lb. Ky. 31 tall fescue_............. Commercial orchardgrass........ Auburn reed canarygrass........ Kentucky bluegrass Tall fescue-ladino clover......... Orchardgrass-ladino clover....... Tall fescue-alfalfa Orchardgrass-alfalfa Reed canary-alfalfa 0 150 0 150 0 150 0 150 0 150 0 150 0 150 0 150 0 150 Oven dry forage per acre 1956 1957 1958 3-yr. av. Lb. 1,690 5,850 1,840 4,400 1,790 3,420 910 1,040 2,400 5,140 1,570 3,570 4,420 7,330 4,350 5,330 3,990 5,120 Lb. 480 5,410 490 4,210 1,030 4,490 260 4,150 3,980 5,650 2,840 4,910 4,730 5,760 4,910 5,840 5,090 6,490 Lb. 540 2,100 230 1,150 140 1,920 510 2,050 3,290 3,330 3,260 3,490 2,540 2,620 2,640 3,250 2,930 2,690 Lb. 900 4,450 850 3,250 990 3,280 560 2,410 3,220 4,710 2,560 3,990 3,900 5,240 3,970 4,810 4,000 4,770 [13] Dry forage lb/acre 2000 - b 150 lb N/acre S No nitrogen Ky.31 toall fescue Orchardgrass Auburn reed canary Ky. bluegross Tall fescue ladino clover Orchardgross ladino clover FIG. 4. February to mid-April forage production of cool season perennial species at Piedmont Substation, 1957-58 average. fescue-ladino clover, and orchardgrass-ladino clover were the most productive species from February to mid-April. Conclusions When fertilized with nitrogen, cool season perennial grasses such as tall fescue alone or in combination with ladino clover furnished grazing over a considerable period of the year in the Piedmont area. Late winter-early spring production was low unless nitrogen was applied. Persistence and productivity declined the third year, probably caused by continued cutting throughout the summer. Other results reported in this circular show that sustained production over a number of years would be more successful if the grasses were not grazed during the summer. EFFECT OF CUTTING FREQUENCY ON PRODUCTIVITY AND PERSISTENCE OF CLOVER IN GRASS AT ALEXANDRIA EXPERIMENT FIELD Goar tall fescue and Boone orchardgrass were each planted alone and in combination with Orbit red or Regal ladino clover [14] on Taft silt loam in September 1967, at Alexandria Experiment Field (located near Anniston in north Alabama but now closed). Each grass or grass-clover combination was harvested under two systems: simulated pasture (cut every 3 to 4 weeks), and hay (cut every 6 to 8 weeks). Grasses were not cut during the MayJune heading period. Nitrogen was applied annually at the rate of 150 pounds per acre on grass alone and 50 pounds per acre on grass-clover mixtures. Results Total annual forage yields over the 2-year period were highest for tall fescue alone or in combination with red clover cut at the hay stage, Table 5. Yields of tall fescue-red clover were sharply reduced and tall fescue alone to a lesser extent by cutting more frequently. Tall fescue-ladino clover cut at the hay stage yielded about the same as orchardgrass or orchardgrass-clover cut at hay stage. Only a small yield reduction occurred with orchardgrass under the pasture system as compared with hay cutting. TABLE 5. FORAGE YIELD OF COOL SEASON PERENNIAL GRASSES AND GRASS-CLOVER MIXTURES AS AFFECTED BY FREQUENCY OF CLIPPING AT ALEXANDRIA EXPERIMENT FIELD, 1968-69 Dry forage per acre Nitrogen Species applied per acre annually Clipped frequently simulated pasture Jan.-early April Total Clipped at hay stage Total Lb. Goar tall fescue................ Goar tall fescue & red clover..... Lb. 1,360 850 1,150 990 590 870 Lb. 5,760 4,770 5,810 4,780 4,380 4,910 Lb. 6,720 Goar tall fescue & ladino clover--Boone orchardgrass Boone orchardgrass & red clover.. Boone orchardgrass & ladino clover 150 50 50 150 50 50 6,470 5,710 5,510 5,520 5,470 Late winter-early spring forage yield was highest with tall fescue alone, Table 5. Yields would normally be higher but the 2-year average includes the establishment year. Orchardgrass alone or with clover was less productive than tall fescue in late winter-spring. Ladino clover was more productive than red clover during this season. The grass species and system of management had a marked effect on persistence and amount of clover present in the forage, Figure 5. Both clovers generally persisted better with orchard[15] Clover in Hay forage,% 40 D Pasture 30 20 10 0 Fescue Orchard Fescue Regal Orchard ladino clover Orbit red clover FIG. 5. Effect of pasture (frequent) clipping and hay cutting on per cent clover in forage at Alexandria Experiment Field. Data collected April 29 of second season. grass than with tall fescue. Under pasture management, red clover stands declined sharply in orchardgrass and were virtually eliminated in tall fescue. Ladino clover, in contrast, was favored by frequent cutting. The different response of the two clovers to cutting management is illustrated in Figure 6. Ladino clover, having leaves close to the ground and many stolons for reserve food storage, tolerates frequent close cutting as in grazing while red clover, an erect-growing plant, can be more easily overgrazed. Differences in persistence between the two clovers would likely have been even more striking by the third year had it not been necessary to terminate the experiment because of closing Alexandria Experiment Field. Conclusions The type of cutting or grazing system had a marked effect on clover persistence and growth. Under simulated grazing, ladino clover was productive in both Goar tall fescue and Boone orchardgrass on Taft silt loam. Red clover, in contrast, was productive when cut in the hay stage but did not persist under simulated grazing. Tall fescue, alone or with clover, furnished more winterearly spring production than orchardgrass. [16] m9cut LADIMD DRDRARD RED ,y d 'Y F y 'c +t 5 1 To;, ~. y i 61, FIG. 6. Effect of pasture (frequent) clipping and hay cutting an persistence of clover in orchardgrass and tall fescue at Alexandria Experiment Field, 2nd year. SUMMER MANAGEMENT STUDIES ON TALL FESCUE, HARDING, AND KOLEAGRASS AT PLANT BREEDING UNIT ltstal lished stan is oit (CXar and hcontu ck :3 tall fcuiei, bardii ggrass, and koleagrass os ('a]aba finic sand, loan i at the Plant Brcediio Visit, located at lallassee iniceiitral A1labanma, wXere clippinig ion aiituinii XXiter ulsedl to stlcd thle eff('t of suinlic I orage p)roductiioni. The (nire experimental area wXas cu t Bin aiitiiin, \Xiniter, and~ sprig, wXith the last har\ cst in late April. summer clippiig? treatmienits XXere comipared ini the \ ears lii of testilig: (a) niot clipped froin eark \lai\ to S(jptembil)r (1 clipped in earl\ Juli; ( c) clipped in iiiid JuL ; and (d) clippedl iil1 Jlie and JuIX \1l plots -were cu t to IcaX e a :3-inch stublei. ( ld grass residue earl Sepotember each \ ear. Nitrogen w~as cut and1 discardled ini wXas adldedl inifoly applicat ioiis at 40) poll] (s per acre, iiiaking a total of 160 poiiiids of niitrog'n per acre. Results forage \icldcs timn-XXinter (O(ctobeor through Felbiiarx) il lie cicasedl :32 per cent XXc Kiiti cl\ .31 tall we (re signiificaiitX in fescue XXas not clipped ill Jilk, Table 6. IeIiio milig forage iii [ 171 TABLE 6. FORAGE YIELD DISTRIBUTION OF KENTUCKY 31 AND GOAR TALL FESCUE AS AFFECTED BY SUMMER CLIPPING, TALLASSEE, ALABAMA Oven dry forage per acre Treatment Kentucky 31 1 Goar Oct.-Feb. Lb. No clipping from early May to Oct.-April Lb. 6,450 6,930 6,150 6,630 Oct.-Feb. Lb. 2,990 2,400 2,620 2,350 Oct.-April Lb. 6,990 6,590 6,760 6,590 September Clipped in early June Clipped in mid-July Clipped in June and July 1 Two-year averages. 2,620 2,580 1,980 2,340 June did not reduce yields. However, when clipped in both June and July, there was a significant loss in yield the following autumn-winter. In this experiment, Kentucky 31 produced an average of 6,500 pounds of dry forage per acre during the cool season, which was similar to Goar production. Analyses for available carbohydrates showed that food reserves are stored in the stem bases of tall fescue plants after maturity (May-June). Because of the nature of this grass, food reserves will be low if forage is removed during late spring or early summer. Such removal results in slower fall growth. In addition, quality of fescue forage is usually low in mid-summer. Autumn and winter yields of Kentucky 31 were not reduced when forage was removed in mid-June. This indicates that grazing can be continued until seed have matured without reducing fall forage production in central Alabama. The data in Table 6 show that removing forage of Goar tall fescue during summer significantly decreased yields in autumn and winter. Clipping in June reduced yields 24 per cent below production of that getting summer rest. Yields were decreased 14 per cent when cutting was delayed until July. Yield reducTABLE 7. SEASONAL FORAGE DISTRIBUTION OF GOAR TALL FESCUE AS AFFECTED BY SUMMER CLIPPING, SECOND SEASON, TALLASSEE, ALABAMA Oven dry forage per acre Treatment Treatment Oct. Lb. Dec. Lb. 690 490 630 370 Feb. Lb. 710 380 630 410 March Lb. 1,050 1,180 1,240 1,150 April Lb. 4,370 4,670 4,420 4,550 Total Oct.-April Lb. 7,870 7,360 7,900 7,160 No clipping early May to September-...... 1,050 640 Clipped in early June.... 980 Clipped in mid-July-.... 680 Clipped in June and July__ [18] clipping we-re cx-en greater tbe second season, indcicating a cuinilatix e effect when tall fescue jpastilres xxcrc g'razedi in sumnmer x ar after xear, Tahle 7. Summer groxxth of Goar is much slower than that of Ken tuckx:31. As a result, it appears that Goar cut in Pune dloes not build ip sufficient food reserx es for rapid fall growvth-. (;oar requircs a longer rest period for inaxiirnlln autumn andl xxinter xicldls than does the Kentuckx :31 xarictx . Fall and winter x icluls of Goar are redulcedl if ax fore is reimx ed from h~ooting util late sutmmner in central Alabamna. iial H-Iardling andtu kolcagrass are pal atale cool season perenn grasses which umake more xwin ter growxth than tall fescuei in central and south Alab~ama. Both grasses hax c beet p flantedi experiii entallv in Alabam a. Sul mner surxixval has b~ein a prob~lem, particiilarlx xxith hardin ggr ass. Inlthus exp~erimntt clipping in sumt cr dlrastical lxredu ced forage \ iclds in at ttunui atndu x xinter. carl 'Table 8. Si tmmemr clipping reduced xields ec cm ore the second season. Crabg~(rass (mroxx thm xxas heax x in kolca, hardingg arass, and tall fescue xvbeti thei grasses xx'cre clipped in suititr, Figure 7. C onmtinuled sutmmer cl ippin g or grazing of these grasses can h~e ex\pectedl to xx aket i stat (s andl redumce prouli ctix it, . Sumtiner clippn deolctcl fonod rcscrx es in grass storagec organ s. Ti s in ax explain the usuial loss of stadl and poor groxxth of hiardiniggrass pasture plantings ini Alabmna. Nexw groxxtih in auitumin is depenidenmt oni stot id food ill the planlt 2 T- si i se are tioiis from summer FIG. 7. Goar toil fescue and hardinggrass rernoan.d fall growth when not clipped during summer. x.,d free and made good xxin tt i producI t ioni ofi 1'Iiarisx spe ci a d tall fescue Icxarictic x x n I. (51:-49:3-197. [ 19 1 TABLE 8. FORAGE YIELD DISTRIBUTION OF HIARDINGGRASS AND KOLEAGRASS AFFECTED BY SUMMER DEFOLIATION, TALLASSEE, ALABAMA AS Oven dry forage per acre Treatment Hardinggrass 1 Koleagrass Oct.-Feb. Lb. No clipping early May to September 2,640 1,280 Clipped in early June________ 1,450 Clipped in mid-July .......... 1,190 Clipped in June and July_ 'Two-year averages. Oct.-April Lb. 7,080 5,900 6,020 5,520 Oct.-Feb. Lb. 3,140 1,890 2,080 1,660 Oct.-April Lb. 6,430 5,390 5,460 4,900 to be successfully grown in Alabama, they must be rested during and after heading in late spring and early summer when food storage occurs in underground plant parts. Conclusions Cool season perennial grasses, particularly in central and south Alabama, require a period of "resting" or minimal grazing from time of seedstalk emergence throughout the summer months if they are to persist and be productive during autumn and early winter. The beneficial effect of summer resting may be attributed to accumulation of food reserves in stem bases or underground storage organs, maintaining buds in a dormant state by shading of seedstalk and leaves, and less weed competition in the sod. SUMMARY Experiments were conducted at five locations in Alabama to study the effects of irrigation, nitrogen, frequency of cutting, stubble height, and summer resting on persistence and productivity of several cool season perennial grasses and grass-legume mixtures. 1. Irrigation did not increase total annual forage yields of most grasses. Kentucky bluegrass and reed canarygrass responded well to irrigation but yields were below that of tall fescue. Orchardgrass-ladino clover was the only grass-legume mixture to give a good response to irrigation but yields were below that of tall fescue fertilized with 160 pounds of nitrogen per acre. 2. Irrigation decreased early spring forage yields, increased weed competition, sharply decreased clover stands, and together with frequent clipping virtually eliminated alfalfa within 2 years. [20] 3. Ladino clover stands persisted longer than alfalfa in association with cool season perennial grasses. 4. When grown with tall fescue and orchardgrass, ladino clover was tolerant of frequent clipping (simulated grazing) but red clover persisted only when cut at hay stage. 5. None of the grass-legume mixtures were as productive as tall fescue fertilized with 150 pounds of nitrogen per acre. 6. Cool season perennial grasses in central and south Alabama required a period of rest or minimal grazing from time of seedstalk emergence throughout the summer months for persistence and maximum productivity during autumn and early winter. ACKNOWLEDGMENT Some of the data reported in this publication were collected by Dr. W. R. Langford, W. A. Ansley, R. A. Burdette, R. D. Hicks, H. W. Grimes, and R. F. Berry, formerly of the Agronomy and Soils Department. Valuable assistance was furnished by E. L. Carden, Agronomy and Soils Department; Dr. G. H. Rollins, Dairy Science Department; E. L. Mayton, Piedmont Substation; J. W. Langford, Plant Breeding Unit; J. K. Boseck, Tennessee Valley Substation; and F. T. Glaze, Prattville Field (formerly at Alexandria Field). [211 AGRICULTURAL EXPERIMENT STATION SYSTEM OF ALABAMA'S LAND-GRANT UNIVERSITY With an agricultural research unit in evern major soil area, Auburn University serves the needs of field crop, live- stock, forestry, and horticultural producers in each region in Alabama. Every citizen of the State has a stake in1 r Q this research program, since any advantage o -I is9 i ° C from new and more economical ways of producing and handling farm products directly benefits the consuming public. Research Unit Identification 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. Tennessee Valley Substation, Belle Mina. Sand Mountain Substation, Crossville. North Alabama Horticulture Substation, Cuilmon. Upper Coastal Plain Substation, Winfield. Forestry Unit, Fayette County. Thorsby Foundation Seed Stocks Farm, Thorsby. Chilton Area Horticulture Substation, Clanton. Forestry Unit, Coosa County. Piedmont Substation, Camp Hill. Plant Breeding Unit, Tallassee. Forestry Unit, Autauga Cnunty. Prattville Experiment Field, Prattville. Black Belt Substation, Marion Junction Tuskegee Experiment Field, Tuskegee. Lower Coastal Plain Substation, Camden. Forestry Unit, Barbour County. Monroeville Experiment Field, Monroeville. Wiregrass Substation, Headland. Brewton Experiment Field, Brewton. Ornamental Horticulture Field Station, Spring Hill. Gulf Coast Substation, Fairhope.