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DATE DUE DATE DUE DATE DUE N09 61093m1 IL_ [—71 ll MSU Is An Aflinnetive Action/Equal Opportunity Institution Warns-at ALTERNATIVE METHODS or ALFALFA ESTABLISHMENT By Jay R. Schmidt A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree 0! MASTER OF SCIENCE Department of Crop and Soil Sciences 1991 ABSTRACT ALTERNATIVE METHODS or ALFALFA ESTABLISHMENT By Jay R. Schmidt Research was conducted in 1989 and 1990 to compare establishment methods for alfalfa. Similar forage yields were obtained between conventional tillage and no-tillage. In the first harvest, forage yield was generally higher where no herbicide was applied compared to where a herbicide was applied; however, alfalfa yield was often decreased. The effect of establishment herbicide was greatest in the first and second harvest of the establishment year. No effect of establishment herbicide was observed in the year following establishment. Weed yields in the year following establishment were generally reduced where alfalfa was seeded with a grass compared to alfalfa seeded alone. 'When alfalfa was seeded with oats, alfalfa yield in the first harvest was reduced compared to alfalfa seeded alone. In the year following establishment, alfalfa yield was often reduced where oats were harvested for grain. ACKNOWLEDGEMENTS I would like to express my appreciation to my committee members Dr. 1.]. Kells, Dr. O.B. Hesterman, and Dr. D. Landis, for their invaluable advice and insight in the planning this project. I would especially like to thank my major advisor Jim Kells for his valuable ideas and support during this project, and allowing me the opportunity to continue my education. I would also like to express my appreciation to Barry Brothers for all the time he contributed to this project. Without his input this project would not have been as successful. Thanks to Geoff List, Andy Chomas, and Joe Bruce for hard work and long hours they all put into the weed separations, and also for their support and friendship. A very special thank you goes to Jodie Hiess for her assistance, love, and patience; and to my parents for their support and encouragement. TABLE OF CONTENTS PAGE LIST OF TABLES ................................................................................................................................. v CHAPTER 1: REVIEW OF LITERATURE ALFALFA PRODUCTION ................................................................................................... 1 NO-TILLAGE CROP PRODUCTION .............................................................................. 4 NO-TILLAGE ALFALFA PRODUCTION ...................................................................... 6 WEED CONTROL IN ALFALFA .................................................................... j .................. 7 BIBLIOGRAPHY .................................................................................................................... 10 CHAPTER 2: COMPARSION OF TILLAGE SYSTEMS AND WEED CONTROL PROGRAMS FOR ALFALFA ESTABLISHMENT ABSTRACT .............................................................................................................................. 14 INT RODUCI'ION ................... 16 MATERIALS AND METHODS ......................................................................................... 18 RESULTS AND DISCUSSION ........................................................................................... 22 Comparison of Tillage Systems ............................................................................... 22 Comparison of Herbicide Programs within Conventional Tillage ................... 28 Comparison of Herbicide Programs within No-tillage ....................................... 32 Economic Comparisons of Tillage Systems and Weed Control Programs ..... 33 Economic Comparisons within Conventional Tillage ......................................... 34 Economic Comparisons within No-Tillage--- ................................... 34 Conclusion ........... . _ - - _ ........................................... 38 BIBLIOGRAPHY ............................................................ 39 iv CHAPTER 3: ALTERNATIVE METHODS OF ESTABLISHING ALFALFA WITHOUT TILLAGE ABSTRACT .......................................................................................... 41 INTRODUCTION.....................-- - -- - ....................................... 43 MATERIALS AND METHODS ........... - ................................................ 45 RESULTS AND DISCUSSION ............................................ 49 Effect of Herbicides on Alfalfa Establishment - .................... 49 Effect of Alfalfa-Grass Mixtures on Establishment ............................................ 57 Effect of Companion Crop Alfalfa Establishment .............................................. 64 Conclusion.-- -- - - ..................... 73 BIBLIOGRAPHY ............................... - _ - .......................................... 74 APPENDIX .............................................. - ..................................................... 76 LIST OF TABLES TABLE PAGE CHAPTER 2: 1 Results of soil tests for the 1989 and 1990 19 experimental areas. 2 Influence of tillage systems on alfalfa populations seeded in the spring of 1989 and 1990 at Kellogg Biological Station, Hickory Corners, Michigan. 23 3 Influence of tillage systems and herbicide programs of dominant weed specie densities in 1989 and 1990 seedings of alfalfa at Kellogg Biological Station, Hickory Corners, Michigan. 24 4 Influence of tillage systems and herbicide programs on total forage, alfalfa, and weed yields for the year of establishment of the 1989 alfalfa seeding at Kellogg Biological Station, Hickory Corners, Michigan. 26 5 Influence of tillage systems and herbicide , programs on total forage, alfalfa, and weed yields for the year of establishment of the 1990 alfalfa seeding at Kellogg Biological Station, Hickory Corners, Michigan. 27 6 Influence of tillage systems and herbicide programs on total forage, alfalfa, and weed yields for the year following establishment, of the 1989 alfalfa seeding at Kellogg Biological Station, Hickory Corners, Michigan. 29 7 Establishment cost estimates for alfalfa seeding using conventional tillage and no-tillage. 35 8 Economic comparisons of tillage systems and weed control programs for the 1989 alfalfa seeding at Kellogg Biological Station, Hickory 36 Corners, Michigan. vi CHAPTER 3: TABLE Economic comparisons of tillage systems and weed control programs for the 1990 alfalfa seeding at Kellogg Biological Station, Hickory Corners, Michigan. Results of soil tests for the 1989 and 1990 experimental areas. Summary of treatments. Influence of establishment herbicides on alfalfa density, seeded in the spring of 1989 and 1990 at Kellogg Biological Station, Hickory Corners, Michigan. Influence of establishment herbicides on dominant weed specie densities in 1989 and 1990 seedings at Kellogg Biological Station, Hickory Corners, Michigan. Influence of establishment herbicides on total forage, alfalfa, and weed yields for the year of establishment of the 1989 seeding at Kellogg Biological Station, Hickory Corners, Michigan. Influence of establishment herbicides on total forage, alfalfa, and weed yields for the year of establishment of the 1990 seeding at Kellogg Biological Station, Hickory Corners, Michigan. Influence of establishment herbicides on total forage, alfalfa, and weed yields for the year following establishment, of the 1989 seeding at Kellogg Biological Station, Hickory Corners, Michigan. Influence of alfalfa-grass mixtures on alfalfa density seeded in the spring of 1989 and 1990 at Kellogg Biological Station, Hickory Corners, Michigan. Influence of alfalfa-grass mixtures on dominant weed specie densities in 1989 and 1990 seedings at Kellogg Biological Station, Hickory Corners, Michigan. vii PAGE 37 46 47 50 51 53 54 56 58 59 APPENDIX TABLE 10 11 12 13 14 15 16 17 Influence of alfalfa-grass mixtures on total forage, alfalfa, forage grass, and weed yields for the year of establishment of the 1989 seeding at Kellogg Biological Station, Hickory Corners, Michigan. Influence of alfalfa-grass mixtures on total forage, alfalfa, forage grass, and weed yields for the year of establishment of the 1990 seeding at Kellogg Biological Station, Hickory Corners, Michigan. Influence of alfalfa-grass mixtures on total forage, alfalfa, forage gas, and weed yields for the year following establishment, of the 1989 seeding at Kellogg Biological Station, Hickory Corners, Michigan. Influence of alfalfa-companion crop seedings on alfalfa density seeded in the spring of 1989 and 1990 at Kellogg Biological Station, Hickory Comers, Michigan. Influence of alfalfa-companion crop seeding on dominant weed specie densities in 1989 and 1990 seedings at Kellogg Biological Station, Hickory Corners, Michigan. Influence of alfalfa-companion crop seeding on total forage, alfalfa, forage grass, and weed yields for the year of establishment of the 1989 seeding at Kellogg Biological Station, Hickory Corners, Michigan. Influence of alfalfa-companion crop seeding on total forage, alfalfa, forage grass, and weed yields for the year of the establishment of the 1990 seeding at Kellogg Biological Station, Hickory Corners, Michigan. Influence of alfalfa-companion crop seedng on total forage, alfalfa, forage grass, and weed yields for the year following establishment, of the 1989 seeding at Kellogg Biological Station, Hickory Corners, Michigan. Influence of establishment program on forage, alfalfa, forage grass, and weed yield for the year of establishment of the 1989 seeding at Kellogg Biological Station, Hickory Corners, Michigan. viii PAGE 60 62 63 66 67 68 69 72 76 TABLE 2 PAGE Influence of establishment program on total forage, alfalfa, forage grass, and weed yields for the year of establishment of the 1990 seeding at Kellogg Biological Station, Hickory Corners, Michigan. 77 Influence of establishment program of total forage, alfalfa, forage grass, and weed yields for the year following establishment of the 1989 seeding at Kellogg Biological Station, Hickory Comers, Michigan. 78 CHAPTER 1 REVIEW OF LITERATURE ALF ALFA PRODUCTION In the past decade, seasonal average hay yield throughout the State of Michigan has increased from 6278 kg ha'1 in 1979 to 8071 kg ha'1 in 1989 (Michigan Agricultural Statistics, 1990). This may be a result of better management practices. Michigan State University recommends the following keys for high quality, high yielding forage (Helsel et al., 1980): 1) establish superior stands of high yielding variety; 2) provide adequate annual fertilization; 3) harvest early; 4) control pests (weeds, insects, and disease); 5) harvest and store properly. Selection of variety should be based upon a) yield potential, b) maturity, c) stand persistence and d) pest resistance (Helsel et al., 1980). Seeding rate should be 13.5 to 18 kg ha“1 and for long term stands 18 kg ha" is recommended (Copeland et al., 1988; Tesar, 1984). Results from Faix et a1. (1979) Show a significantly higher alfalfa density the seeding year, where seeding rate was 13.5 kg ha’1 as compared to 7 kg ha“. The year following establishment no difference was observed. Seeds should be inoculated with specific rhizobia bacteria before planting (Tesar, 1984). This insures nodulation on the roots that take free nitrogen from the air and incorporate it into the plant (Tesar, 1984). Studies at Michigan 2 State University have shown no benefit from lime coated seed when planted in soil pH of 6.8 or higher, as recommended for good alfalfa production (Tesar, 1984). To obtain top yields, alfalfa should be established on well drained productive soils (Helsel et al., 1980). In the spring, plowing and one secondary tillage operation is adequate for seedbed preparation (Tesar, 1984). Band seeding or drilling alfalfa versus surface placement resulted in two to four times as many seedlings initially established and up to 2000 kg ha'1 more yield during the first season (Mueller and Chamblee, 1984; Tesar, 1984). A soil test should be taken prior to seeding and recommendations followed. If pH is below 6.8, lime should be applied and incorporated 3 to 6 months before seeding to adjust the pH to 6.8 or higher (Tesar, 1984). Although a soil test annually would be optimal, a method of calculating nutrient removal may be used to calculate annual fertilization needs would be adequate (Helsel et al., 1980). At seeding time, high phosphorus levels are important for rapid root grth and strong seedling development (Tesar, 1984). Potassium increases alfalfa vigor, thus providing for winter hardiness and a productive stand for many years (Helsel et al., 1980; Tesar, 1984). Cutting management is the next key to high producing forage. A 4-cut system (3 cuts by late August and a 4th in mid to late October) in southern Michigan will produce about 10% more forage than a 3-cut system, and a 3-cut system will produce approximately 25% more forage than a 2-cut system (Helsel et al., 1980). Recommended cutting schedules are based on a compromise of yield, quality, and stand persistence. If harvest is early, quality will be higher, but yield and stand vigor may be decreased. As harvest is delayed, forage quality continues to decline, yields may increase or may even decrease if leaves drop and future cuttings may be lost due to insufficient regrth time. Pest control begins with the first 3 keys, a good stand of quality alfalfa, proper fertilization to maintain vigor, and good cutting management. However, there are times 3 when cultural practices need to be supplemented with herbicides, insecticides, and fungicides for pest control (Helsel et al., 1980). An annual grass companion crop seeded with the alfalfa may reduce the effects of weed competition of the seedling stand (Wolf et al., 1985). Proper moisture is probably the most important factor involved in harvesting and storage (Helsel et al., 1980). Harvest losses increase as the forage dries because of leaf shattering from mechanical harvesting. However, storage losses decline as the moisture level of the forage decreases. Alfalfa hay was produced on over 526,000 hectares in Michigan which was about 20 percent of the total land in field crop production in 1989 (Michigan Agricultural Statistics 1990). Approximately 263,000 hectares in Michigan are considered highly erodible‘. Conservation tillage practices that result in stand establishment without disturbing the soil would be beneficial in reducing soil losses (Roth et al., 1985). In Michigan, no-tillage alfalfa establishment was up 116 percent to a total of 11,400 hectares in 1990 over 1989 (Grigar, 1990). lGrigar, J. January 21, 1991. Personal Communication. United States Department of Agriculture, Soil Conservation Service, East Lansing, MI. NO-TILLAGE CROP PRODUCTION Soil tillage has played an important role in crop production. The primary reason for its use has been weed control. Spring tillage will destroy vegetation and create an even-start condition for crop and weed seeds (Staniforth and Wiese, 1985). Tillage has also been important for incorporation of herbicides and fertilizers, control of insects and diseases, for soil aeration, and removal of previous crop residue (Phillips and Phillips, 1984). Crop producers generally believe that a well prepared seedbed is necessary to promote rapid crop germination. According to Sprague and Triplett (1986), conventional tillage systems may have only 2 to 5 percent soil surface coverage by crop residue in the spring following corn or soybeans. In no-tillage, crop residues may cover 60 to 80 percent of the soil surface the following spring. The absence of tillage may also increase soil water content (Thomas, 1986; Phillips and Phillips, 1984; Unger and McCalla, 1980). This is attributed, in part, to increased water infiltration due to improved soil structure and increased soil porosity (Triplett et al., 1986). Thomas (1986) reported that increased plant residue acts as a barrier which prevents diffusion of water vapor from the soil. This residue also reflects more incoming light than bare soil, resulting in decreased soil temperature and reduced water evaporation. No-tillage crop production, often called no-tillage, zero til], or direct drill, is crop production without the use of tillage prior to planting. No-tillage crop production has many advantages and disadvantages compared to conventional tillage systems. Phillips and Phillips (1984) noted these advantages: 1. reduced soil erosion. 2. ability to crop erosive soils. 5 3. decreased labor requirements (up to 50%). 4. decreased fuel consumption. 5. decreased equipment costs. The ability to reduce both soil erosion and crop production inputs has become increasingly important to crop producers. Phillips and Phillips (1984) also noted several disadvantages to no-tillage crop production. No-tillage planting operations are sometimes delayed due to high soil moisture content and lower soil temperatures as compared to conventional tillage systems. Incidence of diseases, insects, and rodent damage are also more prevalent in no- tillage crop production. The large quantity of crop residue remaining on the soil surface in no-tillage production favors the incidence of insects and diseases which overwinter in these residues. The use of tillage will bury residues thus generally reducing the incidence of insects and disease. NO-TILLAGE ALFALFA PRODUCTION No—tillage alfalfa seedings have been successful in a wide range of planting situations (Buhler and Proost, 1987; Faix et al., 1979; Grant et al., 1982; Linscott et al., 1969; Mueller- Warrant and Koch, 1983; Peters et al., 1984; Sprague, 1952; Taylor and Allinson, 1983; Wolf and Edmisten, 1989; Wolf and White, 1984). Successful alfalfa establishment by either conventional tillage or no-tillage depends on adequately controlling competing vegetation (Tesar and Jackobs, 1972; Martin et al., 1983; Wolf and White, 1984). Buhler and Proost have reported in preliminary work that alfalfa can be successfully established into untilled corn stubble, and that first year yields were similar to those attained with conventional seedings (data unreplicated). From this work they concluded that weed control may be one of the biggest problems with no-tillage alfalfa seedings following row crops. Wolf and White (1984) reported that for successful establishment of alfalfa without tillage the following requirements must be met: 1. living competition must be eliminated. 2. heavy thatch and plant growth tall enough to shade the soil surface must be removed. 3. seedings must be protected against a wide spectrum of insects. 4. seeds must be completely covered with soil but no deeper than 2.5 centimeters. 5. soil fertility must be medium to high with pH 6.4 or higher. There have been many successful attempts of establishing alfalfa without tillage into a perennial grass sod (Taylor and Allinson, 1983; Peters and Zaprzalka, 1981; Mueller- Warrant and Koch, 1983; Hagood, 1988; Martin et al., 1983; Roth et al. 1985). Sprague (1952) worked with chemical sod suppression for no-tillage pasture renovation prior to 1952, 7 TCA was used to control the sod, and an adequate stand of ladino clover and orchardgrass was established. WEED CONTROL IN ALF ALFA Control of existing vegetation is an essential part of establishing alfalfa, because alfalfa is generally slow to establish. (Tesar and J ackobs, 1972; Martin et al., 1983; Wolf and White, 1984). There are two general means of controlling existing vegetation prior to planting: a) cultural/ mechanical and b) chemical. Cultural/ mechanical control can include both tillage and mowing (Peters, 1964). Chemical control of existing vegetation, generally involves the use of contact herbicides, such as paraquat or glyphosate (Peters, 1964; Peters and Lowance, 1972; Wilson, 1986; Linscott, 1978; Roth et al., 1985). Peters (1964) reported mowing did not control broadleaf weeds to the same degree as did herbicides, but alfalfa yields from mowing after the first harvest were similar to herbicide treatments. Where perennial weeds are involved, a herbicide application of paraquat or glyphosate followed by double disking 3 days after application may be recommended (Linscott et al., 1969; Linscott et al., 1978). In a no-tillage situation, options are limited to mowing and herbicides to control existing vegetation. A combination of chemicals and mowing may be needed to kill and then remove the residue so shading of young seedlings does not occur. Paraquat and glyphosate have both been reported as giving adequate suppression of existing vegetation to allow for alfalfa establishment (Martin et al., 1983; Roth et al., 1985; Vogel, 1983; Wolf et al., 1989). Sod suppression with paraquat had no initial effect on alfalfa stand density and alfalfa yield, however about 20% less forage was obtained where paraquat was applied (Mueller and Chamblee, 1984). The reduction in forage yield appeared to be from weeds controlled by paraquat. Glyphosate generally only requires one application, but requires 8 adequate coverage of leaf area for absorption and translocation (Wolf et al., 1989). For hard to control perennial weeds, such as quackgrass with paraquat, usually requires at least a split application approximately 6 weeks apart (Wolf et al., 1989), and is not recommended for this use (Kells and Renner, 1991). EPTC and benefin may be used in conventional tillage for control of annual grasses and certain annual broadleaf weeds (Peters, 1964; Wilson, 1986). EPTC and benefin must be mechanically incorporated immediately after application, therefore neither are currently options for no-tillage. EPTC can effectively control weeds without reducing stand density or causing significant injury to the alfalfa (Wilson, 1986; Peters, 1964). Postemergence herbicides are options for both conventional tillage and no-tillage. 2,4-DB and bromoxynil are two postemergence herbicides that selectively control annual broadleaf weeds. Excellent control with 2,4-DB has been reported (Wilson, 1986; Peters, 1964; Peters and Lowance, 1972). Bromoxynil also provides excellent control of annual broadleaf weeds, however if air temperature exceeds 21 C within 3 days after application unacceptable injury may occur (Kells and Renner, 1991; Cosgrove, 1990). Sethoxydim is a selective postemergence herbicide which controls most annual grasses in alfalfa (Cosgrove, 1990; Kells and Renner, 1991). Grasses must be actively growing for best results. With the use of herbicides, a weed control program may be designed to control most weed problems, but in alfalfa is herbicidal weed control necessary? Forage yield in the first cutting are sometimes reduced where a herbicide is applied (Dutt et al., 1983; Wilson, 1986; Fawcett and Harvey, 1978). The yield reductions probably reflected reductions in weed populations due to herbicide treatments (Wilson, 1986; Fawcett and Harvey, 1978). Wilson (1986) also reported that second cutting forage yields were higher where EPTC and 2,4-DB was applied compared to the untreated plots. Annual weeds did not affect stand density. 9 Wilson (1986) also reported herbicide treatments did not affect crude protein content of first or second cutting forage. Annual weeds were found by Martin and Anderson (1975) to differ in crude protein content. Redroot pigweed (24%), common lambsquarters (26%), and common cocklebur (24%) had similar crude protein content similar to alfalfa (26%), while crude protein content of yellow foxtail (22%) and barnyardgrass (22%) was significantly lower than that of alfalfa. Peters et al. (1984) reported alfalfa yield to be similar where herbicides were applied compared to the untreated plots. Controlling broadleaf weeds with herbicides such as 2,4-DB generally increased yield of grassy weeds (Peters, 1964). The year following establishment, alfalfa yield and alfalfa stand density were not significantly different due to treatments of EPTC or 2,4-DB (Peters, 1964). Are weeds a problem in established stands? In some studies, weed control has resulted in increased alfalfa yields (Harvey et al., 1976; Kapusta and Stricker, 1976) and in others, yields were similar or reduced from the control (Robins et al., 1978; Swan, 1978). Cosgrove and Barrett (1987) reported that alfalfa yield may be increased by weed control in established stands of alfalfa, but these increases are dependent on stand density and the degree of weed infestation. In a case of severe weed infestation, removal of the weed component of the total forage by a herbicide application may cause a decrease in first harvest forage yield. However, this will increase the percentage of alfalfa. If the weed infestation is light, very little benefit is realized from herbicide application, since alfalfa percentage is already high and weed infestation is not limiting production. Wilson (1981) has reported controlling weeds in established alfalfa may increase yield and quality. BIBLIOGRAPHY Buhler, DD, and RT. Proost. 1987. Alfalfa establishment using reduced tillage methods. Forage Producers Handbook, 11th Forage Production and Use Symposium, Wisconsin Forage Council, January 27, 28, 1987. Copeland, L.O., O.B. Hesterman, F.J. Pierce, and MB. Tesar. 1988. Seeding practices for Michigan. Cooperative Extension Bulletin E-2107, Michigan State University, E Lansing, MI. Cosgrove, DR. 1990. Experience with no-till forage establishment in Wisconsin. Proceedings: Wisconsin Forage Council’s 14th Forage Production and Use Symposium, Wisconsin Dells, WI. 14:49-55. Cosgrove, DR, and M. Barrett. 1987. Effects of weed control in established alfalfa (Medicago sativa) on forage yield and quality. Weed Sci. 35:564-567. Dutt, T.E., R.G. Harvey, and RS. Fawcett. 1983. Influence of herbicides on yield and botanical composition of alfalfa hay. Agron. J. 75:229-233. Faix, J.J., D.W. Graffis, and OJ. Kaiser. 1979. Conventional and zero-till planted alfalfa with various pesticides. Ill. Agr. Exp. Sta. DSAC 7:117-123. F awcett, RS. and R.G. Harvey. 1978. Field comparison of seven dinitroaniline herbicides for alfalfa (Medicago sativa) seedling establishment. Weed Sci. 26:123-127. Grigar, J. 1990. 1990- Michigan conservation tillage survey. United States Department of Agriculture, Soil Conservation Service, East Lansing, MI. Hagood, E.S., Jr. 1988. Herbicide treatments for no-till alfalfa, Medicago sativa L., establishment in sod. Weed Tech. 2:327-332. Harvey, R.G., D.A. Rohweder, and RS. Fawcett. 1976. Susceptibility of alfalfa cultivars to triazine herbicides. Agron. J. 68:632-634. Helsel, Z.R., M.B. Tesar, R. Leep, and J .W. Thomas. 1980. Alfalfa, Quality means profits. Cooperative Extension Bulletin E-1413, Michigan State University, East Lansing, MI. Kapusta, G., and CF. Stricker. 1976. Selective control of downey brome in alfalfa. Weed Sci. 23:202-206. Kells, J.J., and KA Renner. 1991. Weed control guide for field crops. Cooperative Extension Bulletin E-434, Michigan State University, East Lansing, MI. Linscott, D.L., A.A. Akhavein, and RD. Hagin. 1969. Paraquat for weed control prior to establishing legumes. Weed Sci. 17:428-431. 10 11 Linscott, D.L., R.D. Hagin, and T. Tharawanich. 1978. Control of yellow nutsedge (Cyperus esculentus) and other weeds before summer planting of alfalfa (Medicago sativa). Weed Sci. 26:399-402. Martin, G.C., and RN. Anderson. 1975. Forage nutritive value and palatability of 12 common annual weeds. Crop Sci. 15:823-827. Martin, N.P., C.C. Sheaffer, D.L. Wyse, and DA. Schriever.‘ 1983. Herbicide and planting data influence establishment of sod-seeded alfalfa. Agron. J. 75:951-955. Michigan Agricultural Statistics Service. 1990. Michigan agricultural statistics. Michigan Agricultural Statistics Service, Lansing, MI. Moshier, L., and D. Penner. 1978. Use of glyphosate in sodseeding alfalfa (Medicago sativa) establishment. Weed Sci. 26:163-166. Mueller, JP, and D.S. Chamblee. 1984. Sod-seeding of ladino clover and alfalfa as influenced by seed placement, seeding date, and grass suppression. Agron. J. 76:284- 289. Muelller-Warrant, G.W., and D.W. Koch. 1983. Fall and spring herbicide treatment for minimum-tillage seeding of alfalfa (Medicago sativa) Weed Sci. 31:391-395. Peters, El, and SA. Lowance. 1972. Bromoxynil, chloroxynil, and 2,4-DB for establishing alfalfa and medium red clover. Weed Sci. 20:140-142. Peters, EJ. 1964. Pre-emergence, preplanting, and postemergence herbicides for alfalfa and birdsfoot trefoil. Agron. J. 56:415-419. Peters, El, R.A. McKelvey, and R. Mattas. 1984. Controlling weeds in dormant and nondormant alfalfa (Medicago sativa). Weed Sci. 32:154-157. Peters, RA, and J. Zaprzalka. 1981. Impact of carbofuan treatment on no-tillage alfalfa establishment. Proc. NE. Weed Sci. Soc. 35:76. Phillips, RE, and SH. Phillips. 1984. o-t' a e a iculture rinci les and ractices. Van Nostrand and Reinhold Co., New York. p. 3-9. Robinson, L.R., C.F. Williams and W.D. Laws. 1978. Weed control in established alfalfa. Weed Sci. 26:37-40. Roth, G.W., D.D. Wolf, and ES. Hagood Jr. 1985. Alfalfa establishment without tillage as influenced by insecticide and vegetation suppression. Grass and Forge Sci. 40:473- 478. Sprague, MA. and GB. Triplett, ed. -tilla e ace- ° a e iculture. John Wiley and Sons, Inc. 1986. p. 12-15. 12 Sprague, MA. 1952. The substitution of chemicals for tillage in pasture renovation. Agron. J. 44:405-409. Staniforth, D.W., and AF. Wiese. 1985. Weed biology and its relationship to weed control in limited-tillage systems. p. 16-22. In Weed Control in Limited Tillage Systems. A.F. Wiese, ed. Weed Science Soc. Am., Champaign, IL. Swan, D.G. 1978. Effects of repeated herbicide application on alfalfa (Medicago sativa). Weed Sci. 26:151-153. Taylor, R.W., and D.W. Allinson. 1983. Legume establishment in grass sods using minimum-tillage seeding techniques without herbicide application: forage yield and quality. Agron. J. 75:167-172. Tesar, MB and LA. Jackobs. 1972. Establishing the stand. p. 415-435. In C.H. Hanson, ed., Alfalfa Science and Technology. Am. Soc. Agron., Madison, WI. Tesar, M.B., 1984. Good stands for top alfalfa production in Michigan, Cooperative Extension Bulletin E-1017, Michigan State University, East Lansing, MI. Thomas, G.W. 1986. Mineral nutrition and fertilizer placement. p. 94-99. In No-tillage afnd Surface-Tillage Agriculture. MA. Sprague and GB. Triplett, eds. John Wiley and Sons, Inc. Triplett, G.B., Jr., D.M. VanDoren, Jr., and BL. Schmidt. 1968. Effect of corn stover mulch on no-tillage corn yield and water infiltration. Agron. J. 60:236-239. Unger, D.W., and TM. McCalla. 1980. Conservation tillage systems. Adv. Agron. 33:1-58. Vogel, KR, W.R. Kehr, and BE. Anderson. 1983. Sod-seeding alfalfa into cool season grasses and grass-alfalfa mixtures using glyphosate or paraquat. J. Range Manage. 36:700-702. Wilson, R.G. 1986. Weed control in irrigated seedling alfalfa (Medicago sativa). Weed Sci. 34:423-426. Wilson, R.G., Jr. 1981. Weed control in established dryland alfalfa (Medicago sativa). Weed Sci. 29:615-618. Wolf, DD. and HE. White. 1984. No-till alfalfa establishment. Forage Systems: leading US. agriculture into the future. Pub: American Forage and Grassland Council, Lexington, KY. Wolf, D.D., E.S. Hagood, Jr., and M. Lentner. 1985. No-till alfalfa establishment as influenced by previous cover crops. Can. J. Plant Sci. 65:609-613. Wolf, D.D., K.L. Edmisten, and HE. White. 1989. No-till alfalfa planting in late winter following fall vegetation suppression with herbicides. Crop Sci. 29:396-399. 13 Wolf, DD, and KL. Edmisten. 1989. Late season alfalfa plantings: Conventional vs. no-till methods. Crop Sci. 29:170-175. CHAPTER 2 COMPARISON OF TILLAGE SYSTEMS AND WEED CONTROL PROGRAMS FOR ALFALFA ESTABLISHMENT ABSTRACT Research was conducted in 1989 and 1990 to compare establishment systems for alfalfa. Treatments included a comparison of conventional tillage and no-tillage for establishment of alfalfa in the spring following corn harvested for silage. Within each tillage system a series of four weed control programs varying in herbicide intensity were compared. Alfalfa plant densities 45 days after planting were higher for conventional tillage than no-tillage in 1989; however in 1990 alfalfa plant densities were not significantly different between tillage systems. By the fall of both years, there were no differences in alfalfa plant density. Total forage yield was not significantly different between tillage systems in the establishment year for both years, or the year following establishment for the 1989 seeding. In the first harvest with conventional tillage in 1989, there was a higher total forage yield when no herbicide was used than where a herbicide was used; however, there was no difference in pure alfalfa yield between weed control programs. In no-tillage, there was no significant difference in total forage yield; however, there was a higher pure alfalfa yield where the intense herbicide program was used than the no herbicide program. By the third harvest of the 1989 seeding and the second harvest of the 1990 seeding of the establishment year, there were no differences in forage yield or alfalfa yield between herbicide programs. In the first harvest 14 15 with no-tillage, there was a significantly higher total forage yield when no herbicide was used than the intense herbicide program; however the intense herbicide program had a higher alfalfa yield than the no herbicide program in both years. In 1989 in the third harvest, there was no difference in total forage yield between weed control programs, but the intense herbicide program still had a higher alfalfa yield than the no herbicide program. In 1990 by the second harvest, there were no differences in forage yield or alfalfa yield between weed control programs. No significant differences were observed between herbicide programs in either tillage system the year following establishment of the 1989 seeding. Nomenclature: alfalfa, Medicago sativa L.; corn, Zea mays L. INTRODUCTION Alfalfa establishment has been accomplished by seeding into a conventionally tilled seedbed, usually prepared by both primary and secondary tillage operations. Preplant incorporated herbicides or an annual grass companion crop have been used to reduce the effect of weed competition with the alfalfa seedlings (Wolf et al., 1985). Seed is usually broadcast or drilled, followed by packing to create adequate seed to soil contact. This type of establishment would leave the soil vulnerable to erosion. With nearly 10 percent of Michigan’s land in crop production classified as highly erodible, it would be very desirable to establish alfalfa without tillage‘. No-tillage seedings have been successful in a wide range of planting situations (Mueller- Warrent and Koch, 1980; Wolf et. al., 1985). Research has shown that yields of alfalfa established without tillage using either glyphosate [N -(phosphonomethyl) glycine] or pa raquat (1,1’-dimethyl-4-4’-bibyridinium ion) were equivalent or better than yields obtained from conventional seeding (Roth et. a1. 1985). Most research has involved seeding alfalfa into a grass sod or permanent pasture, while comparatively little research has been reported for alfalfa seedings following corn. Buhler and Proost (1987) reported first year forage yields were similar to those attained with conventional seeding following corn (data unreplicated). lGrigar, J. January 21, 1991. Personal Communication. United States Department of Agriculture, Soil Conservation Service, East Lansing, MI. 16 From this preliminary work, they concluded that weed control may be one of the biggest problems with no-tillage alfalfa seedings. Non-selective herbicides are appropriate to control existing vegetation prior to planting. Paraquat has been shown to provide control of existing vegetation before planting (Taylor et. al., 1969; Martin et.al., 1983). The use of selective herbicides is limited to post emergence herbicides. EPTC (S-ethyl dipropylcarbamothioate) is a common preplant incorporated herbicide that is very effective in controlling annual grasses. However since EPTC must be mechanically incorporated it is not an option in a no-tillage system. Sethoxydim[2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one] and 2,4-DB [(2,4-dichlorophenoxy)acetic acid] are two common selective herbicides used in alfalfa. Sethoxydim is used to control most annual grasses, and 2,4-DB is used to control broadleaf weeds. Research has shown that 2,4-DB does not increase alfalfa plant density, however alfalfa yield was significantly higher where 2,4-DB had been applied (Sand and McCarthy, 1959; Peters and Lowance, 1971). Wilson (1986) reported annual weeds did not reduce alfalfa stand density compared to where herbicides were used to control the weeds. Where weeds were controlled by herbicides in seedling alfalfa, total forage yield was reduced compared to the untreated in the first harvest (Dutt et al., 1983; Fawcett and Harvey, 1978; Wilson, 1986). Wilson (1986) also reported that second cutting forage yields were higher where herbicides were applied than where no herbicide was applied. However, Peters et al. (1984) reported similar alfalfa yield where herbicides were applied compared to the untreated plots. The objectives of this study were: 1) to determine the effects of establishment methods (no-tillage verses conventional tillage) for alfalfa on plant density, and forage yield, and 2) to study the effect of weed control systems on alfalfa density, weed density, forage yield and its components in both conventional tillage and no-tillage. 17 MATERIALS AND METHODS Research was conducted in adjacent experimental areas in 1989 and 1990 at the Kellogg Biological Station, Hickory Corners, Michigan. The soil type was a Kalamazoo sandy loam (coarse-loamy, mixed, mesic Typic Hapludalf). Results from two soil tests taken in the fall of 1988 and spring of 1990, for both experimental areas, are summarized in Table 1. Lime was applied on November 3, 1988 at 2240 kg ha“, to both experimental areas, to adjust soil pH. Proper potassium level was obtained through the addition of 448 kg ha'1 of K20 in the form of 0-0-60 on April 24, 1990 to the 1990 experimental area. Potassium was not required for the 1989 experimental area. Glyphosate was applied to both experimental areas at 2.2 kg ha'1 on September 27, 1988 and to the 1990 experimental area on September 29, 1989 to control quackgrass. The study was conducted in a split plot design with four replications. Main plots consisted of two tillage systems, conventional tillage and no-tillage. Sub-plots consisted of four weed control programs varying in herbicide intensity. Plots were 2.4 meters wide and 9.1 meters in length. ‘Big Ten’ alfalfa was seeded on May 5 and May 2 for the 1989 and 1990 seedings, respectfully. In 1989, a seeder2 equipped with power coulters spaced 12.3 cm apart was 2John Deere Power-Till Drill, John Deere Co. Inc., Moline, Illinois. 18 19 was can 8m in 3:9: season we. . E“ 3m 8m EEC ”3298.3 an... 84 new man 335 828%“: S: :2 E: 2.3 3:9: 8325 fin fin Wm MN AQSV c832 £5ch 3 ma 8 3 ma so... =8 3.8... mom son. mom so... mom 8% £2 82 £2 8:. 38555 82 82355135 one .303 Rucogconxo 32 new $3 05 how 8mm: :8 mo $38M .~ Seek 20 used, and in 1990 a seeder3 utilizing a fluted coulter and double disk openers spaced 12.3 cm apart was used. Both seeders were calibrated to deliver 16.8 kg ha", and place seed 0.5 cm deep. The conventional tillage seedbed was prepared by moldboard plowing in the spring followed immediately with one pass with a tandem disk about one week before planting. Two passes with a shovel cultivator at a depth of 7.5 cm was used to prepared the final seedbed and also provide incorporation for preplant incorporated herbicide treatments. The no-tillage seedbed consisted of corn residue that was harvested for silage in the fall prior to seeding. Herbicides were applied with a tractor mounted compressed air sprayer. All applications utilized 8003 flat fan4 nozzles which delivered 206 L ha‘l at a spray pressure of 248 kPa. Herbicide programs included: 1) no herbicide; 2) paraquat (.5 kg ha"); 3) paraquat (.5 kg ha") + 2,4-DB (1.1 kg ha"); 4) EPT C (3.3 kg ha '1) + paraquat (.5 kg ha“) + 2,4-DB (1.1 kg ha"). EPTC treatments were applied preplant incorporated in conventional tillage plots and surface applied in no-tillage plots, on May 3 and May 1 for the 1989 and 1990 seedings, respectfully. Non ionic surfactant was added to all paraquat treatments at 0.25% v/v. Paraquat treatments were surface applied immediately prior to seeding 2,4-DB was applied postemergence to alfalfa at the 1 to 2 trifoliolate leaf stage on June 6 and June 7 for the 1989 and 1990 seedings, respectfully. The herbicide treatments were chosen so that the study would provide data on both herbicide programs and tillage systems. One herbicide treatment within each tillage system is considered impractical, however they were included to complete the factorial design and to allow for direct comparisons between tillage systems. 3Tye No-Tillage Drill, The Tye Co., Lockney, Texas. ‘Spraying Systems Co., North Ave. and Schmale Road, Wheaton, IL 60188. 21 Populations of alfalfa and the three dominant weed species were determined on June 19 and June 18, for the 1989 and 1990 seedings, respectfully. Dominant weed species were redroot pigweed (Amaranthus retroflexus L.), common lambsquarters (Chenopodium album L.), and velvetleaf (Abutilon theophrasti Medicus) in 1989, and common chickweed (Stellaria media (L.) Vill.), common lambsquarters, and velvetleaf in 1990. Plant populations are reported as the mean of three 1 In2 quadrats per plot selected at random. Alfalfa populations were also determined in the fall of the establishment year on November 20, 1989 and November 9, 1990. For the 1989 seeding, alfalfa plant density was evaluated in the spring of the year following establishment on April 24, 1990. Three forage harvests were made in the year of establishment for both the 1989 and 1990 seedings, and four harvests were made in the year following establishment for the 1989 seeding. Harvest dates for the 1989 seeding were July 14, August 23, and October 10, 1989, and May 30, July 5, August, 14 and October 23, 1990. Harvest dates for the 1990 seeding July 25, September 4, and October 23, 1990. An area 1.2 meters wide and 9.1 meters in length was harvested from the center of each plot with a mechanical flail harvester5. The total forage fresh weight from this area was measured. A random sub-sample was collected from the harvested forage and the fresh weight of the sub-sample was measured. Sub- samples were oven dried and dry weights were measured. Total forage dry weight yield was calculated. A sample was also collected at each harvest to determine forage composition. Samples were collected by cutting a strip along the edge of the harvested area 20 cm wide and 9.1 meters in length, then randomly collecting a 300 to 400 gram sample. Samples were separated into fractions of alfalfa, dominant weed species, other broadleaf weeds and other ’Carter Manufacturing Co. Inc., Brookston, IN. 22 grassy weeds. Dominant weeds were redroot pigweed, common lambsquarters, and velvetleaf in 1989, and common lambsquarters, velvetleaf, and common chickweed in 1990. Samples were oven dried and weights measured. Weights were used to calculate percent forage composition. Analyses of variance were performed on the data and means were separated by least significant difference at the 5% level of significance. RESULTS AND DISCUSSION Comparison of Tillage Systems. At the spring evaluation for the 1989 seeding, conventional tillage treatments had on average 77 plants In'2 more alfalfa plants than no- tillage treatments (Table 2). This difference may be due to the seeder used in 1989. This seederdid not adequately close the slot to produce good seed to soil contact in the no- tillage area. At the fall evaluation and the spring following the year of establishment, no significant difference in alfalfa density was observed. No significant difference was observed at either the spring or fall evaluation in the year of establishment for the 1990 seeding, however in the spring there was a trend towards a higher plant density in no-tillage. Wolf and White (1984) reported significantly higher alfalfa plant densities in no-tillage than conventional tillage in the spring following establishment. At the fall evaluation, the alfalfa density between the two years was nearly identical. In the 1989 seeding, redroot pigweed and common lambsquarters density was higher in conventional tillage than no-tillage where no herbicide, and paraquat + 2,4-DB had been applied (Table 3). Common lambsquarters also had a higher plant density in conventional 23 Table 2. Influence of tillage systems and herbicide programs on alfalfa densities seeded in the spring of 1989 and 1990 at the Kellogg Biological Station, Hickory Corners, Michigan. Year following Year of Establishment Establishment Establishment Program Spring Fall Spring (plants In") 1989 Seeding Conventional Tillage No Herbicide 233 136 91 Paraquat 192 151 95 Paraquat + 2,4-DB 185 132 86 EPTC + Paraquat + 2.4-DB 208 147 109 bio-Tillage No Herbicide 101 101 84 Paraquat 151 108 89 Paraquat + 2,4-DB 137 109 81 EPTC + Paraquat + 2.4-DB 121 116 87 LSDW,‘ 70.9 NS. NS. LSDW,” NS. NS. NS. 1990 Seeding Conventional tillage No Herbicide 193 102 -- Paraquat 194 101 - Paraquat + 2.4-DB 195 97 - EPTC + Paraquat + 2.4-DB 165 110 - No-Tillage N0 Herbicide 204 109 - Paraquat 269 111 - Paraquat + 2.4-DB 290 114 - EPTC + Paraquat + 2.4-DB 270 106 - LSDwf NS. NS. - LSDW,” NS. NS. - ‘Comparisons valid between tillage systems within herbicide programs and years. ”Comparisons valid between herbicide programs within tillage systems and years. 24 @889? own—E :12? $52on 02635: 50.53 33> Eaten—Ea? .mEEmoE 02328: 5:23 mEonzm own—E 59503 213 2813600.. 6826—020 .8888 um—zmhm u~2$>8>uEDm< nmcotazvaEB :oEE8nA\> oemmd an afloat...“ 2:3 no: noun—oi 358303 3:08am. 9.8 .aaacmcmm 58w c8 peanuts: vn + 2 «80 + £82 3.8 .3383“ own—G c8 @8322 en + m— «80 + «an: 2.8 33058 + 38 32.35 0205.2 as, 8%. x + 2 ago + «as? 88 .33..ch -- N + as $3539 + e3? 38 L235 -- m + QB 332280 + £32 acumen—ohm 68 L235 -- e + we 58% + £32 3.: mafia + 38 .3388 -- as £32 38 .332£ -- M3: 332. -- -- mg: was“? ........... 9.2 wxv----------- 92 use 8am van «.0502 8am 02033: 3583— SO mfiooom powwow no.5 25:58: no Exp—85m .N fines 48 Paraquat was applied on May 4 and May 1 for the 1989 and 1990 seedings, respectfully. 2,4-DB was applied postemergence to alfalfa at the 1 to 2 trifiolate leaf stage on June 6 and June 7 for the 1989 and 1990 seedings, respectfully. Sethoxydim [2-[1- (ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen- l-one] was applied to 7.5 to 9.6 cm tall cats on June 6 and June 7 for the 1989 and 1990 seedings, respectfully. Populations of alfalfa and two dominant weed species were determined on June 19 and June 18, for the 1989 and 1990 seedings, respectfully. Dominant weed species were redroot pigweed (Amamnthus retroflaus L.) and common lambsquarters (Chenopodium album L.) in 1989, and velvetleaf (Abutilon theophrasti Medicus) and common lambsquarters in 1990. Plant populations are reported as the mean of three 1 m2 quadrats per plot selected at random. Alfalfa populations were also determined in the fall of the establishment year on November 20 and November 9 for the 1989 and 1990 seedings, respectfully. For the 1989 seeding, alfalfa plant density was evaluated in the spring of the year following establishment on April 24, 1990. Three forage harvests were made in the year of establishment for both the 1989 and 1990 seedings, and four harvests were made in the year following establishment for the 1989 seeding. Harvest dates for the 1989 seeding were July 14, August 23,and October 10, 1989, and May 30, July 5, August 14, and October 23, 1990. Harvest dates for the 1990 seeding were July 25, September 4, and October 23, 1990. An area 1.2 meters wide and 9.1 meters in length was harvested from the center of each plot with a mechanical flail harvester’. The total forage fresh weight from this area was measured. A random sub-sample was collected from the harvested forage, and the fresh weight of the sub-sample measured. Sub-samples were oven dried, and dry weights measured. Total forage dry weight yield was calculated. 3Carter Manufacturing Co. Inc., Brookston, Indiana. 49 A sample was also collected at each harvest to determine forage composition. Samples were collected by cutting a strip along the edge of the harvested area 20 cm wide and 9.1 meters in length, then randomly collecting a 300 to 400 gram sample. Samples were separated into fractions of alfalfa, forage grass, dominant weed species, other broadleaf weeds, and other grassy weeds. Samples were oven dried and weights measured. Weights were used to calculate percent forage composition. Analyses of variance were preformed on the data, and means were separated by least significant difference at the 5% level of significance. RESULTS AND DISCUSSION Effect of herbicides on alfalfa establishment. The discussion in this section will include the three herbicide treatments. There was no significant difference in alfalfa plant density where no herbicide was applied compared to where paraquat + 2,4 DB was applied (Table 3). Alfalfa plant densities, evaluated in the spring of the establishment year, were significantly higher where paraquat was applied than where no herbicide or paraquat + 2,4- DB was applied in both years (Table 3). Weed pressure where no herbicide was applied may have reduced alfalfa plant density, and the 2,4-DB where paraquat + 2,4-DB was applied, may have reduced alfalfa plant density. However, this is in contrast to Wilson (1986), who reported that in conventional tillage, herbicides, in particular, 2,4-DB, did not reduce alfalfa plant density. By the fall of the establishment year, no significant differences were observed in alfalfa plant density among herbicide treatments in both years (Table 3). No differences in alfalfa plant density were observed the year following establishment for the 1989 seeding (Table 3). 50 Table 3. Influence of establishment herbicides on alfalfa density, seeded in the spring of 1989 and 1990 at Kellogg Biological Station, Hickory Corners, Michigan. Year following Alfalfa Year of Establishment Establishment Establishment , , Program Spring Fall Spring (plants n1") 1989 Seeding No Herbicide 100 104 79 Paraquat 161 120 85 Paraquat + 2,4oDB 108 96 82 mD('m). 44 N.S. N-So 1990 Seeding No Herbicide 220 113 -- Paraquat 318 126 -- Paraquat + 2,4-DB 260 122 -- LSDW,‘ 51 NS. -- 'Comparisons valid within columns and years. 51 Redroot pigweed yield was not significantly different among herbicide programs; however, there was a trend of higher redroot pigweed yield where a herbicide was applied compared to where no herbicide was applied in 1989 (Table 4). In contrast, common lambsquarters density was sigiificantly higher where no herbicide was applied compared to where a herbicide was applied (Table 4). Common lambsquarters may have been emerged and therefore controlled by the paraquat application. Control of common lambsquarters may have allowed the redroot pigweed to become established. In 1990, common lambsquarters density appeared higher where paraquat was applied than where no herbicide or paraquat + 2,4-DB was applied; however, this difference was not significant (Table 4). This would suggest that another weed species may have been eliminated by the paraquat application which then provided an opportunity for common lambsquarters to become established. Postemergence application of 2,4-DB controlled the common lambsquarters. Velvetleaf was not sigtificantly different between herbicide progams in 1990 (Table 4). Total forage yield was significantly higher where no herbicide was applied than where a herbicide was applied in the first harvest of the 1989 seeding (Table 5). Alfalfa yield was significantly lower where no herbicide was applied compared to where a herbicide was applied in 1989. Total broadleaf weeds attributed to the reduction in alfalfa yield and the higher total forage yield. Common lambsquarters yield, total broadleaf weed yield and total weed yield were sigiificantly higher where no herbicide was applied than where a herbicide was applied. Total forage yield was significantly reduced where paraquat + 2,4- DB was applied compared to where paraquat was applied; however, alfalfa yields were Similar. This suggests that weeds made up the difference in total forage yield. Total forage yield was significantly higher where paraquat was applied than where "0 herbicide was applied in the first harvest of the 1990 seeding (Table 6). This is in contrast to what was observed in 1989. Alfalfa yields were not significantly different 52 Table 4. Influence of establishment herbicides on dominant weed specie densities in 1989 and 1990 seedings at Kellogg Biological Station, Hickory Corners, Michigan. Alfalfa 1989 Seeding 1990 Seeding Establishment Progam AMARE' CHEAL‘ CHEAL‘ ABUTHa (plants In") N o Herbicide 1 5 1 2 Paraquat 28 0 16 2 Paraquat + 2,4-DB 12 0 0 1 LSDms,b NS. 3 NS. NS. 'AMARE = redroot pigweed; CHEAL = common lambsquarters; ABU'I'H = velvetleaf. bComparisons valid within columns. 53 Table 5. Influence of establishment herbicides on total forage, alfalfa. and weed yields for the year establishment of the 1989 seeding at Kellogg Biological Station. Hickory Corners. Michigan. Yield Alfalfa Total Total Establishment Broadleaf Grassy Total Program Forage Alfalfa AMARE' CHEAL' Weeds Weeds Weeds (10 kg ha") Harvest l .\'o Herbicide 427 38 28 78 336 3 339 Paraquat 268 212 24 12 33 3 56 Paraquat + 2.4-DB 202 197 2 0 3 2 5 LSme" 61 85 NS. 65 94 NS. 98 Harvest 2 No Herbicide 159 138 1 0 20 1 21 Paraquat 230 191 2 0 10 29 39 Paraquat + 2.4-DB 249 219 3 0 17 13 30 LS 0‘0“," 5 1 77 NS. N .S. N .S. N.S. N3. ‘ Harvest 3 No Herbicide 141 135 0 0 3 3 6 Paraquat 172 164 0 0 1 7 8 Paraquat + 2.4-DB 186 183 0 0 0 3 3 LSDmm,‘ 39 41 NS. NS. NS. NS. NS. ‘AMA RE . redroot pigweed; CHEAL - common lambsquarters. ”Comparisons valid within columns and harvests. 54 Table 6. Influence of establishment herbicides on total forage. alfalfa. and weed yields for the year of establishment of the 1990 seeding at Kellogg Biological Station, Hickory Corners, Michigan. Yield Alfalfa Total Total Establishment Broadleaf Grassy Total Program Forage Alfalfa CHEAL‘ ABUTH‘ Weeds _ Weeds Weeds (10 kg ha") Harvest 1 No Herbicide 285 223 3 34 57 5 62 Paraquat 374 310 5 50 64 0 64 Paraquat + 2,4-DB 301 301 0 0 0 0 0 LSDwm)” 85 N.S. N.S. N.S. N.S. N.S. N.S. Harvest 2 No Herbicide 232 219 0 2 4 9 13 Paraquat 284 279 0 0 1 4 5 Paraquat + 2,4-DB , 261 252 0 0 0 9 9 1.80m”," N.S. N.S. N.S. N.S. N.S. N .S. N.S. Harvest 3 No Herbicide 146 142 0 0 3 1 4 Paraquat 199 199 0 0 0 0 0 Paraquat + 2,4-DB 190 190 0 0 0 0 0 LSDmm,b N.S. N.S. N.S. N.S. N.S. N.S. N.S. aCHEAL . common lambsquarters; ABUTH :- velvetleaf. bComparisons valid within columns and harvests. 55 between herbicide progams, however there is a trend toward a higher alfalfa yield where herbicide was applied than where no herbicide was applied. Weed yields were not significantly different between herbicide treatments, but a trend toward lower total broadleaf yields and total weed yield was observed where paraquat. + 2,4-DB was applied compared to where no herbicide or paraquat was applied. In the second harvest of the 1989 seeding, a lower total forage yield was obtained where no herbicide was applied than where a herbicide was applied (Table 5). Alfalfa yield was significantly lower where no herbicide was applied than where paraquat + 2,4-DB was applied. No significant differences were observed in total forage yield or alfalfa yield between the paraquat and paraquat + 2,4-DB treatments. Weed yields were not significantly different between herbicide progams. In 1990, herbicide progams had no significant effect on total forage yield, alfalfa yield, or weed yields in the second harvest (Table 6). In the third harvest of the 1989 seeding, a lower total forage yield and alfalfa yield was observed where no herbicide was applied than where paraquat + 2,4-DB was applied. No significant differences were observed in weed yields (Table 5). In the third harvest of the 1990 seeding, no significant differences were observed in total forage yield, alfalfa yield, or weed yields (Table 6). No significant differences were observed in total forage yield, or alfalfa yield in any harvest, the year following establishment of the 1989 seeding (Table 7). In the first harvest, total broadleaf weeds were significantly lower where paraquat + 2,4-DB was applied compared to where paraquat was applied. In the second, third and fourth harvest, weeds were not significantly different, and were not a major problem. Grassy weed yield was significantly higher in the second harvest where paraquat was applied than where no herbicide was applied, and in the third and fourth harvest significantly higher than where 56 Table 7. Influence of establishment herbicides on total forage, alfalfa, and weed yields for the year following establishment, of the 1989 seeding at Kellogg Biological Station, Hickory Corners, Michigan. Yield Alfalfa Total Total Establishment Broadleaf Grassy Total Program Forage Alfalfa Weeds Weeds Weeds (10 kg ha") Harvest 1 No Herbicide 569 549 16 4 20 Paraquat 579 542 37 O 37 Paraquat + 2,4-DB 579 570 3 6 9 LSDwm)“ N.S. N.S. 26 N.S. N.S. Harvest 2 No Herbicide 327 319 5 3 8 Paraquat 358 341 1 16 17 Paraquat + 2,4-DB 342 333 0 9 9 LSD(0_05,' N.S. N.S. N. . 12 N.S. Harvest 3 No Herbicide 302 298 1 3 4 Paraquat 280 257 1 22 23 Paraquat + 2,4-DB 304 300 0 4 4 LSDWM' N.S. N.S. N. . 14 N.S. Harvest 4 No Herbicide 253 249 2 2 4 Paraquat 262 233 1 28 29 Paraquat + 2,4-DB 263 252 0 10 11 LSDwm,‘ N.S. N.S. 2 18 18 'Comparisons valid within columns and harvests. 57 no herbicide or paraquat + 2,4-DB was applied. Broadleaf weeds were not significantly different in the first, second, and third harvests; however, in the fourth harvest gass weed yield contributed enough where paraquat was applied to make total weed yield higher where paraquat was applied compared to where no herbicide or paraquat + 2,4-DB was applied. Effect of Alfalfa-Grass Mixtures on Establishment. The discussion in this section will include the three alfalfa mixtures and alfalfa seeded alone where paraquat was applied. Alfalfa plant density was not significantly different among alfalfa-gass mixtures at the spring or fall evaluation for the 1989 and 1990 seedings or the spring of the year following establishment for the 1989 seeding (Table 8). Alfalfa plant density was reduced where alfalfa was seeded with smooth bromegass or orchardgass compared to alfalfa seeded alone in the spring evaluation for the 1989 seeding. In 1990, alfalfa plant density was reduced where alfalfa was seeded with a gas compared to alfalfa seeded alone. No significant difference was observed in alfalfa plant density at the fall evaluation for the 1989 or 1990 seedings or the spring evaluation of the year following establishment for the 1989 seeding. No significant differences were observed in weed densities between alfalfa gass mixtures and alfalfa seeded alone in the spring following establishment for either the 1989 or the 1990 seeding (Table 9). In 1989, the alfalfa gass mixtures appeared to have no effect on redroot pigweed density or common lambsquarters density; however, in 1990 a trend toward a lower common lambsquarters density was observed where alfalfa-gass mixtures were seeded compared to alfalfa seeded alone. Total forage yield was not significantly different between alfalfa gass mixtures and alfalfa seed alone at any harvest in the 1989 seeding (Table 10). Alfalfa yield in the first harvest was reduced where alfalfa was seeded with smooth bromegass compared to alfalfa 58 Table 8 Influence of alfalfa-gass mixtures on alfalfa density seeded in the spring of 1989 and 1990 at Kellogg Biological Station, Hickory Corners, Michigan. Year following Alfalfa Year of Establishment Establishment Establishment , . Progam Spring Fall Spring (plants m") 1989 Seeding Alone 161 120 85 + Smooth Bromegass 102 106 83 + Orchardgass 108 89 83 + Timothygass 145 93 83 LSDW,‘ 44 N.S. N.S. 1990 Seeding Alone 318 126 ' -- + Smooth Bromegass 223 127 -- + Orchardgass 202 102 ~- + Timothygass 248 111 -- ISD(05). 51 N.S. " 'Comparisons valid within columns and years. 59 Table 9. Influence of alfalfa-gass mixtures on dominant weed specie densities in 1989 and 1990 seedings at Kellogg Biological Station, Hickory Corners, Michigan. Alfalfa 1989 Seeding 1990 Seeding Establishment Progam AMARE‘ CHEAL‘ CHEAL‘ ABUTHa (plants m") Alone 28 0 16 2 4» Smooth Bromegass 34 1 1 3 + Orchardgass 25 1 1 0 + Timothygass 36 1 0 3 LSDms,h N.S. N.S. N.S. N.S. 'AMARE = redroot pigweed; CHEAL = common lambsquarters; ABUTH = velvetleaf. l’Comparisons valid within columns. 60 Table 10. Influence of alfalfa-grass mixtures on total forage. alfalfa. forage grass, and weed yields for the year of establishment of the 1989 seeding at Kellogg Biological Station. Hickory Corners. Michigan. Yield Alfalfa Total Toral Esrablishment Forage Broadleaf Grassy Total Program Forage Alfalfa AMARE' CHEAL' Grass Weeds Weeds Weeds (10 kg ha") Harvest 1 Alone 268 213 24 12 53 2 55 + Smooth bromegass 226 96 58 3 10 117 3 120 + Orchardgass 280 185 39 8 7 85 3 88 e Timothygass 262 165 51 1 5 85 7 92 1.50.035," N.S. 85 N.S. N.S. N.S. N.S. N.S. Harvest 2 - Alone 230 191 2 0 10 29 39 v Smooth bromegass 233 193 4 13 7 21 12 33 + Orchardgass 245 167 2 13 3 21 54 75 + Timonhygrass 229 186 5 6 6 18 19 37 LSDmm,’ N.S. N.S. N.S. N.S. ' NS. N.S. N.S. Harvest 3 Alone 172 164 0 0 1 7 8 + Smooth bromegass 190 164 0 0 20 2 4 6 + Orchardgass 184 148 0 0 34 2 0 2 + Timothygass 196 184 0 0 3 1 8 9 LSD,M,," N.S. N.S. N.S. N.S. N.S. N.S. N.S. ‘AMARE - redroot pigweed; CHEAL - common lambsquarters. “Comparisons valid within columns and harvests. 61 seeded with orchardgass, timothygass or alone. Weed yields were not significantly different between alfalfa-gass mixtures and alfalfa seeded alone. A significantly higher total forage yield was obtained where alfalfa was seeded with smooth bromegass compared to where alfalfa was seeded with orchardgass or timothygrass in the first harvest of the 1990 seeding (Table 11). No significant differences were observed where alfalfa was seed alone compared to alfalfa seeded with a gass. Alfalfa yield or weed yields were not significantly different among alfalfa-gass mixtures and alfalfa seeded alone. A trend appeared in the first harvest of the 1989 and 1990 seeding that total broadleaf weed yield was suppressed where alfalfa was seeded with orchardgass or timothygass compared to alfalfa seeded with smooth bromegass (Tables 10, 11). This trend may have influenced the significantly lower alfalfa yield in the 1989 seeding, and the higher total forage yield in the 1990 seeding with the alfalfa-smooth bromegass mixture. In the second harvest of the 1989 and 1990 seedings, and the third harvest of the 1989 seeding, no significant differences were observed in total forage yield, alfalfa yield, or weed yields between alfalfa-gass mixtures and alfalfa seeded alone (Tables 10, 11). Total forage yield, alfalfa yield, and total broadleaf weed yield was not different among alfalfa gass mixtures and alfalfa seeded alone in the third harvest of the 1990 seeding (Table 11). Grassy weed yield was significantly higher where alfalfa was seeded with timothygass compared to alfalfa seeded alone, or with smooth bromegass or orchardgass. A trend similar to this appeared in the 1989 seeding. Timothygass appeared to not gow as vigorously in the fall of the establishment year, which may have allowed room for gassy weeds to appear. Total forage yield, alfalfa yield, total gassy weed yield and total weed yield was not significantly different in the first harvest the year following establishment for the 1989 seeding (Table 12). Broadleaf yield was significantly reduced where alfalfa was seeded with 62 Table 11. Influence of alfalfa-grass mixtures on total forage, alfalfa. forage grass. and weed yields for the year of establishment of the 1990 seeding at Kellogg Biological Station, Hickory Corners. Michigan. Yield Alfalfa Total Total Establishment Forage Broadleaf Grassy Total Program Forage Alfalfa CHEAL‘ ABUTH' Grass Weeds Weeds Weeds (10 kg ha") Harvest 1 Alone 374 310 5 50 64 O 64 + Smooth bromegass 454 365 3 24 17 68 4 72 - Orchardgrass ' 328 263 7 0 29 28 8 36 + Timothygass 338 296 2 4 8 24 9 34 LSDmm" 85 N.S. N.S. N.S. N.S. N.S. N.S. Harvest 2 Alone 284 279 0 0 1 4 5 4» Smooth bromegass 301 288 0 0 0 2 11 13 + Orchardgass 274 201 0 0 56 1 16 17 - Timothygass 278 260 0 0 13 0 5 5 LSDmm,” N.S. N.S. N.S. N.S. NS N.S. N.S. Harvest 3 Alone 199 199 0 0 0 0 0 v Smooth bromegass 204 197 0 0 6 1 0 l + Orchardgass 186 139 0 0 47 O 0 0 + Timothygass 184 169 0 0 0 1 14 15 LSDWW" NS. N.S. N.S. N.S. N.S. 5 10 ‘CHEAL - common lambsquarters; ABUTH - velvetleaf. ”Comparisons valid within columns and harvests. 63 Table 12. Influence of alfalfa-gass mixtures on total forage, alfalfa, forage gass, and weed yields for the year following establishment, of the 1989 seeding at Kellogg Biological Station Hickory Corners, Michigan. Yield Alfalfa Total Total Establishment Forage Broadleaf Grassy Total Program Forage Alfalfa Grass Weeds Weeds Weeds (10 kg ha“) Harvest 1 Alone 579 542 36 1 37 + Smooth bromegass 622 540 82 0 0 0 + Orchardgass 620 509 109 2 0 2 + Timothygass 599 S46 51 2 O 2 LSDMS,‘ N.S. N.S. 26 N.S. 29 Harvest 2 Alone 358 341 1 16 17 + Smooth bromegass 325 308 5 2 10 12 + Orchardgass 340 294 46 0 0 O + Timothygass 327 322 3 1 1 2 LSDwm; N.S. 32 N.S. 12 14 Harvest 3 Alone 280 257 1 22 23 + Smooth bromegass 324 313 6 3 2 5 + Orchardgass 308 245 63 0 0 0 + Timothygass 331 323 1 1 6 7 LSDwm,‘ 50 52 N.S. 14 N.S. Harvest 4 Alone 262 233 1 28 29 + Smooth bromegass 259 253 1 2 3 5 + Orchardgass 262 201 48 0 13 13 + Timothygass 269 266 0 0 3 3 LSDwm,‘ N.S. 38 2 18 18 ‘Comparisons valid within columns and harvests. 64 a gass compared to alfalfa seeded alone. The competition from the gass may have suppressed germination of the weeds. Total forage yield was not different among alfalfa-gass mixtures and alfalfa seeded alone in the second harvest (Table 12). Alfalfa yield was lower where alfalfa was seeded with smooth bromegass or orchardgass compared to alfalfa seeded alone. Grassy weed yield and total weed yield was significantly higher where alfalfa was seeded alone than alfalfa seeded with orchardgass or timothygass. Alfalfa seeded with timothygass had higher total forage yield than alfalfa seeded alone in the third harvest (Table 12). Alfalfa yield was significantly higher where alfalfa was seeded with smooth bromegass, or timothygass compared to alfalfa seeded alone, or with orchardgass. Grassy weed yield was significantly higher where alfalfa was seeded alone compared to alfalfa seeded with a gas. This may explain the lower alfalfa yield where alfalfa was seeded alone. The alfalfa yield reduction may be lower where alfalfa was seeded with orchardgass due to the high yield of orchardgass. Total forage yield in the fourth harvest was not significantly different between alfalfa-gass mixtures and alfalfa seeded alone (Table 12). Alfalfa yield was reduced where alfalfa was seeded with orchardgass compared to alfalfa seeded with smooth bromegass or timothygass. The combination of orchardgass and gassy weeds may be the cause of the alfalfa reduction. Total gassy weeds were significantly higher where alfalfa was seeded alone compared to alfalfa seeded with smooth bromegass or timothygass. Effects of Companion Crop Alfalfa Establishment. The discussion in this section will include the three alfalfa companion crop seeding and alfalfa seeded alone where paraquat was applied. Alfalfa plant density was not significantly different among oat companion crop removal methods; however alfalfa plant density was significantly lower where alfalfa was seeded with a companion crop compared to alfalfa seeded alone in the spring evaluation of 65 the establishment year for both the 1989 and 1990 seedings (Table 13). No significant difference was observed in alfalfa plant density between oat removal methods or alfalfa seeded alone in the fall evaluation for the 1989 and 1990 seedings or the spring of the year following establishment for the 1989 seeding. No significant differences in weed densities were observed among oat removal methods or with alfalfa seeded alone in the spring following establishment for both the 1989 and the 1990 seedings (Table 14). In 1989, the alfalfa-oat companion crop appeared to have no effect on common lambsquarters density; however, redroot pigweed density appears to be higher where alfalfa was seeded alone or oats were killed with herbicide compared to where oats were harvested as silage or gain. In 1990, a trend toward a lower common lambsquarters density was observed where alfalfa was seeded with an oat companion crop compared to alfalfa seeded alone. Data suggests the oats may have suppressed common lambsquarters germination. Forage was not harvested where oats were harvested for gain at the first harvest after establishment. Where oats were harvested as silage, a higher total forage yield and a lower alfalfa yield was observed compared to where alfalfa was seeded alone and where oats were killed with herbicide in the first harvest in the 1989 seeding (Table 15). Redroot pigweed yield was significantly lower where oats were harvested for silage than where oats were killed with herbicide. No other significant differences were observed in weed yield among oat removal methods and alfalfa seeded alone. However where cats were harvested for silage, there was a trend toward a lower broadleaf weed yield than where oats were killed with herbicide. Total forage yield was significantly lower where oats were killed with herbicide compared to oats harvested as silage or alfalfa seeded alone in the first harvest of the 1990 66 Table 13. Influence of alfalfa-companion crop seedings on alfalfa density seeded in the spring of 1989 and 1990 at Kellogg Biological Station, Hickory Corners, Michigan. Year following Alfalfa Year of Establishment Establishment Establishment . . Progam Sprnng Fall Sprnng (plants m'z) 1989 Seeding Alone 161 120 85 + Oats (killed with herb) 74 85 87 + Oats (silage) 113 100 88 + Oats (gain) 72 73 63 LSDWS,‘ 44 N.S. N.S. 1990 Seeding Alone 318 126 -- + Oats (killed with herb) 195 129 -- + Oats (silage) 166 103 -- + Oats (gain) 189 111 -- LSD(05). 51 N.S. " 1'Comparisons valid within columns and years. 67 Table 14. Influence of alfalfa-companion crop seeding on dominant weed specie densities in 1989 and 1990 seedings at Kellogg Biological Station, Hickory Corners, Michigan. Alfalfa 1989 Seeding 1990 Seeding Establishment . . . . . Progam AMARE CHEAL CHEAL ABUTH (plants m‘z) Alone 28 0 16 2 + Oats (killed with herb) 33 0 0 1 + Oats (silage) 11 1 0 0 + Oats (gain) 15 2 1 0 Lspm,b N.S. N.S. N.S. N.S. 'AMARE = redroot pigweed; CHEAL = common lambsquarters; ABUTH = velvetleaf. bComparisons valid within columns. 68 Table 15. Influence of alfalfa-companion crop seeding on total forage, alfalfa. forage pass. and weed yields for the year of establishment of the 1989 seeding at Kellogg Biological Station. Hickory Corners, Michigan. Yield Alfalfa Total Total Establishment Forage Broadleaf 'Grassy Total Program Forage Alfalfa AMARE' CHEAL‘ Grass Weeds Weeds Weeds (10 kg ha“) Harvest 1 Alone 2 212 24 12 53 3 56 + Oats (killed with herb.) 243 145 74 3 98 0 98 # Oats (silage) 406 31 2 0 343 29 3 32 + Oats (grain) LSDmm,’ 61 85 63 N.S. NS. N.S. N.S. Harvest 2 Alone 230 191 2 0 10 29 39 + Oats (killed with herb.) 196 177 1 2 19 0 19 4 Oats (silage) 168 147 1 0 16 5 21 + Oats (grain) 175 119 11 o 18 38 56 LSDmm" 51 N.S. 8 N.S. N .5. NS. N .8. Harvest 3 Alone 172 164 0 0 1 7 8 + Oats (killed with herb.) 159 158 0 0 1 0 1 + Oats (silage) 166 155 0 0 9 2 11 + Oats (grain) 103 85 0 0 2 16 18 LSDWW" 39 41 N.S. N.S. 6 8 11 'AMARE - redroor pigweed; CHEAL - common lambsquarters. “’Comparisons valid within columns and harvests. 69 seeding (Table 16). Alfalfa yield followed the same pattern as the 1989 seeding where alfalfa yield was reduced where oats were harvested as silage compared to oats killed with herbicide or alfalfa seeded alone. No significant differences were observed in weed yield among oat removal methods and alfalfa seeded alone. .It appears that velvetleaf yield was reduced where alfalfa was seeded with an oat companion crop compared to alfalfa seeded alone; however, no significant differences were observed due to the high degee of variability in weed yield. In the second harvest of the 1989 seeding, total forage yield was not significantly different among oat removal methods; however, where oats were harvested for silage or gain total forage yield was significantly lower than where alfalfa was seeded alone (Table 15). Alfalfa yield was not significantly different among oat removal methods and alfalfa seeded alone; however, a trend in the data suggest that alfalfa yield was lower where cats were harvested for silage or gain compared to alfalfa seeded alone. Redroot pigweed yield was significantly higher where oats were harvested for gain compared to oats killed with herbicide or harvested for silage or alfalfa seeded alone. No significant differences were observed in total broadleaf weed yield, total gassy weed yield, or total weed yield among oat removal methods and alfalfa seeded alone. In 1990, no significant differences were observed in total forage yield, alfalfa yield, or weed yield in the second harvest (Table 16). The same trend appeared in the 1990 seeding that appeared in the 1989 seeding that alfalfa yield appeared to be lower where oats were harvested for silage or gain than alfalfa seeded alone. Total forage yield and alfalfa yield in the third harvest of the 1989 seeding was significantly lower where oats were harvested for gain compared to where alfalfa was seeded alone or oats were killed with herbicide or harvested for silage (Table 15). Total broadleaf weed yield was higher where oats were harvested for silage than alfalfa seeded 70 Table 16 Influence of alfalfa-companion crop seeding on total forage, alfalfa. forage grass. and weed yields for the year of establishment of the 1990 seeding at Kellogg Biologial Station. Hickory Corners. Michigan. Yield Alfalfa Total Total Establishment Forage Broadleaf Grassy Total Program Forage Alfalfa CHEAL‘ ABUTH‘ Grass Weeds Weeds Weeds (10 ks ht") Harvest 1 Alone 374 310 5 50 64 0 64 + Oats (killed with herb.) 214 209 0 2 5 0 5 + Oats (silage) 327 24 0 0 293 10 0 10 v Oats (grain) LSDtm,” 85 103 N.S. N.S. N.S. N.S. N.S. Harvest 2 Alone 284 279 0 0 1 4 5 + Oats (killed with herb.) 273 271 0 0 2 2 + Oats (silage) 210 169 0 0 26 2 13 15 + Oats (grain) 311 198 0 0 102 0 11 11 LSDW”,b N.S. N.S. N.S. N.S. N.S. N.S. N.S. Harvest 3 Alone 199 199 0 0 0 0 0 + Oats (killed with herb.) 193 192 0 0 1 0 1 + Oats (silage) 151 148 0 0 1 2 3 + Oats (gain) 192 177 0 0 1 14 15 LSDmm" N.S. N.S. N.S. N.S. N.S. 5 10 ‘CHEAL I common lambsquarters; ABUTH - velvetleaf. t’Comptnrisons valid within columns and harvests. 71 alone, or where oats were killed with herbicide or harvested for grain. Total grassy weed yield was significantly higher where oats were harvested for grain compared to alfalfa seeded alone, or where oats were killed with herbicide or harvested for silage. No significant differences were observed in total forage yield, alfalfa yield, or total broadleaf weed yield in the third harvest of the 1990 seeding (Table 16). Grassy weeds followed a similar pattern in the 1990 seeding compared to the 1989 seeding, where total grassy weed yield was significantly higher where oats were harvested for grain compared to alfalfa seeded alone, or where oats were killed with herbicide or harvested for silage. Total forage yield and alfalfa yield in the first harvest of the year following establishment for the 1989 seeding was significantly lower where oats were harvested for grain than where alfalfa was seeded alone or where oats were killed with herbicide or harvested for silage (Table 17). Total broadleaf weed yield was higher where alfalfa was seeded alone or where oats were harvested for grain compared to where oats were killed with herbicide. Total grassy weed yield and total weed yield was significantly higher where oats were harvested for grain compared to alfalfa seeded alone or where oats were killed with herbicide or harvested as silage. Total forage yield and alfalfa yield in the second harvest of the year following establishment for the 1989 seeding was significantly lower where oats were harvested for grain compared to alfalfa seeded alone or where oats were killed with herbicide (Table 17). Total broadleaf weeds were lower where alfalfa was seeded alone compared to where oats were harvested as silage or grain. Where alfalfa was seeded alone, a higher total grassy weed yield was observed compared to alfalfa seeded with oats. In the third harvest, no significant differences in total forge yield were observed among oat removal methods and alfalfa seeded alone (Table 17). Alfalfa yield was 72 Table 17. Influence of alfalfa-companion crap seeding on total forage, alfalfa, forage grass, and weed yields for the year following establishment, of the 1989 seeding at Kellogg Biological Station, Hickory Corners, Michigan ‘ Yield Alfalfa Total Total Establishment Forage Broadleaf Grassy Total Program Forage Alfalfa Grass Weeds Weeds Weeds (10 kg ha") Harvest 1 Alone 579 542 37 0 37 + Oats (killed with herb.) 609 600 9 0 9 + Oats (silage) 567 547 I3 7 20 + Oats (grain) 486 418 36 32 68 LSDMS,‘ 59 68 26 15 29 Harvest 2 Alone . 358 341 l 16 17 + Oats (killed with herb.) 355 348 7 0 7 + Oats (silage) 337 323 10 4 14 + Oats (grain) 309 294 12 3 15 LSDmm,‘ 34 32 7 9 12 N.S. Harvest 3 Alone 280 257 I 22 23 + Oats (killed with herb.) 298 298 0 0 0 + Oats (silage) 328 324 2 2 4 + Oats (grain) 305 296 1 8 9 LSDWM' N.S. 52 N.S. 14 N.S. Harvest 4 Alone 261 232 1 28 29 + Oats (killed with herb.) 240 240 0 0 0 + Oats (silage) 257 253 2 . 2 4 + Oats (grain) 258 250 3 5 8 LSDmm‘ N.S. N.S. 2 18 18 aComparisons valid within columns and harvests. 73 significantly higher where oats were harvested as silage compared to alfalfa seeded alone. Total grassy weed yield was higher where alfalfa was seeded alone compared to alfalfa seeded with oats. In the fourth harvest, total forage yield and alfalfa yield was not significantly different among oat removal methods and alfalfa seeded alone (Table 17). Total grassy weed yield and total broadleaf weed yield was higher where alfalfa was seeded alone compared to oat removal methods. A complete set of data is included in the appendix. Conclusion. By the fall of the establishment year, alfalfa plant densities were similar among herbicide programs. Generally in the first harvest where herbicides were applied, there was a higher percentage of alfalfa than where no herbicide was applied. Forage yield and alfalfa yield may be reduced in the second and third harvest of the establishment year where no herbicide is applied compared to where herbicides are applied. Alfalfa-grass mixtures may be seeded successfully without tillage and similar or better forage yields maintained compared to alfalfa seeded alone. By the fall of the establishment year, alfalfa plant densities were similar among alfalfa-grass mixtures and! alfalfa seeded alone. - Companion crop alfalfa seeding was also successful without tillage. Similar alfalfa plant densities were observed in the fall of the establishment year. In the first harvest where oats were seeded, alfalfa yield was reduced compared to alfalfa seeded alone. Generally where oats were harvested for grain, there was a greater amount of weeds in the forage than where cats were removed earlier in the second and third harvest of the establishment year. BIBLIOGRAPHY Casler, MD. and RN. Drolsom. 1984. Yield testing cool-season forage grasses in pure stands vs. binary mixtures with alfalfa. Crop Sci. 24:453-456. Drolsom, RN. and D. Smith. 1976. Adapting species for forage mixtures. p. 223-232. In R.I. Papendick et al.(ed.) Multiple cropping ASA, Madison, WI. Dutt, R.G. Harvey, R.S. Fawcett, NA. Jorgensen, H.J. Larsen, and DA. Schlough. 1979. Forage quality and animal performance as influenced by quackgrass (Agropyron repens) control in alfalfa (Medicago sativa) with pronamide. Weed Sci. 27:127-132. Fawcett, R.S., R.G. Harvey, D.A. Schlough and LR. Block. 1978. Quackgrass (Agropyron repens) control in established alfalfa (Medicago sativa) with pronamide. Weed Sci. 26:193-198. Grigar, J. 1990. 1990-Michigan conservation tillage survey. United States Department of Agriculture, Soil Conservation Service, East Lansing, Mi. Johnson, J.R. and IT Nichols. 1965. Production, crude protein, and use of irrigated grasses and alfalfa-grass combinations on clay soils in western South Dakota. South Dakota Ag. Exp. Stn. Bull. 555. Klebesadel, LJ. and D.Smith. 1960. Effects of harvesting an oat companion crop at four stages of maturity on the yield of cats, on the light near the soil surface, on soil moisture, and on the establishment of alfalfa. Agron. J. 52:627-630. Mueller-Warrant, G.W. and D.W. Koch. 1980. Establishment of alfalfa by conventional and minimum tillage seeding techniques in a quackgrass-dominant sward. Agron. J. 72:884-889. Peters, EJ., R.A. McKelvey, and R. Mattas. 1984. Controlling weeds in dormant and nondormant alfalfa (Medicago sativa). Weed Sci. 32:154-157. Peters, RA. 1961. Legume establishment as related to the presence or absence of an oat companion crop. Agron. J. 53: 195-198. Roth, G.W., D.D. Wolf, adn E.S. Hagood Jr. 1985. Alfalfa establishment without tillage as influenced by insecticide and vegetation suppression. Grass and Forage Sci. 40:473- 478. Smith, D. 1960. Yield and chemical composition of oats for forage with advance in maturity. Agron. J. 52:637-639. Tesar, MB. 1984. Good stands for top alfalfa production in Michigan. Coop. Ext. Bull. E- 1017. Michigan State University, East LansingMI. 74 75 Tesar MB. and V.L. Marble. 1988. Alfalfa establishment. A.A. Hanson, D.K. Barnes and RR. Hill, Jr. (ed.) Alfalfa and Alfalfa Improvement. Agron. 29:303-332. Wilson, R.G. 1986. Weed control in irrigated seedling alfalfa (Medicago sativa). Weed Sci. 34:423-426. Wolf, D.D., E.S. Hagood, Jr., and M. Lentner. 1985. No-till alfalfa establishment as influenced by previous cover crop. Can. J. Plant Sci. 65:609-613. APPENDIX 76 Appcmlit Table 1. Influence of establishment program on total forage. alfalfa. forage grass, and weed yields for the year of establishment of the 1989 seeding at Kellogg Biological Station. Hickory Corners. Michigan. Yield _ Total Total Establishment Forage Broadleaf Grassy Total Program Forage Alfalfa AMARE' CHEAL' Grass Weeds Weeds Weeds (10 kg ha") Harvest 1 No Herbicide 427 88 28 78 336 3 339 Paraquat 268 212 24 12 53 3 55 Paraquat + 2.4-DB 203 197 2 0 3 2 5 Alfalfa + Smooth Brome 226 95 58 3 11 117 3 120 Alfalfa + Orchardgrass 280 I85 39 8 8 85 3 88 Alfalfa + Timothygrass 262 165 51 1 5 85 7 92 Oats (killed with herb.) 242 144 74 3 98 0 98 Oats (harv. for silage) 406 31 2 0 343 29 3 32 Oats (harv. for grain) LSD‘W,‘ 61 85 63 65 94 N.S. 98 Harvest 2 No Herbicide 160 I38 1 1 20 1 21 Paraquat 230 191 2 0 10 29 39 Paraquat + 2,4-DB 249 219 3 0 I7 13 30 Alfalfa + Smooth Brome 233 193 4 l3 7 21 12 33 Alfalfa + Orchardgrass 245 167 2 13 4 22 54 75 Alfalfa + Timothygrass 229 I86 5 6 6 18 20 37 Oats (killed with herb.) I95 177 I 2 I9 0 19 Oats (harv. for silage) I68 147 I 0 17 5 21 Oats (ban. for grain) 175 119 II 0 18 39 56 LSD“, a,” 51 77 8 N.S. N S 49 N.S. Harvest 3 No Herbicide I41 135 0 0 3 3 6 Paraquat 172 164 0 0 1 7 8 Paraquat + 2.4-DB 187 183 0 0 0 3 3 Alfalfa 4» Smooth Brome I90 I64 0 0 21 2 4 6 Alfalfa + Orchardgrass 184 148 0 0 34 2 0 2 Alfalfa + 'I‘imothygrass 196 184 0 0 3 1 8 9 Oats (killed with herb.) 159 158 0 0 I 0 I Oats (harv. for silage) 166 155 0 0 9 2 11 Oats (harv. for grain) 103 85 0 0 2 16 18 LSD“; 39 41 N5 N.S. 6 9 11 ‘AMARE - redroot pigweed; CHEAL - common lambsquarters. ”Comparisons valid within columns and harvests. 77 Ali/mull: Table 2. Influence of establishment program on total forage. alfalfa. forage grass. and weed yields for the year of establishment of the 1990 seeding at Kellogg Biological Station. Hickory Corners. Michigan. Yield Total Total Establishment Forage Broadleaf Grassy Total Program Forage Alfalfa CHEAL' ABUTH“ Grass Weeds Weeds Weeds (10 ks ha") Harvest 1 No Herbicide 285 223 3 34 58 5 ' 62 Pa raquat 374 310 5 50 64 0 64 Paraquat + 2.4-DB 301 301 0 0 0 0 0 Alfalfa + Smooth Brome 454 365 3 24 18 68 4 72 Alfalfa + Orchardgrass 329 263 7 0 29 28 8 36 Alfalfa + Timothy Grass 338 296 2 4 8 24 9 34 Oats (killed with herb.) 214 209 0 2 5 0 5 Oats (harv. for silage) 327 24 0 0 294 10 0 IO Oats (harv. for grain) 1.50.0.5,” 85 103 N.S. N S. N.S. N S N S Harvest 2 No Herbicide 232 219 0 2 4 10 13 Paraquat 284 279 0 0 l 4 5 Paraquat + 2,4-DB 261 252 0 0 0 9 9 Alfalfa 4» Smooth Brome 301 288 0 0 0 2 ll 13 Alfalfa + Orchardgrass 274 201 0 0 56 1 16 17 Alfalfa + Timothy Grass 278 260 0 0 13 0 5 5 Oats (killed with herb.) 273 271 0 0 2 0 2 Oats (harv. for silage) 210 I69 0 0 27 2 13 15 Oats (harv. for grain) 310 198 0 0 102 0 11 11 LSDum,‘ N.S. N.S. N.S. N3 N.S. NS NS Harvest 3 No Herbicide 146 142 0 0 3 l 4 Paraquat 199 I99 0 0 0 0 0 Paraquat + 2.4-DB 190 190 0 0 0 0 0 Alfalfa + Smooth Brome 204 197 0 0 6 I 0 1 Alfalfa + Orchardgass 186 139 0 0 47 0 0 0 Alfalfa 4- Timothy Grass 184 169 0 0 0 1 14 16 Oats (killed with herb.) I93 192 0 0 1 0 1 Oats (harv. for silage) 151 148 0 0 1 2 2 Oats (harv. for grain) 192 I77 0 0 1 15 15 L505”: N.S. N.S. NS N.S. N.S. 5 10 ‘CHEAL - common lambsquarters; ABUTH - velvetleaf. ”Comparisons valid Within columns and harvests. 78 .‘lppcmliz Table 3. Influence of establishment program of total forage, alfalfa. forage grass. and weed yields for the year following establishment, of the 1989 seeding at Kellogg Biological Station. Hickory Corners. Michigan. Yield Total Total Establishment Forage Broadleaf Grassy Total Program Forage Alfalfa Grass Weeds Weeds Weeds (10 kg ha") Harvest I No Herbicide 569 549 16 4 20 Paraquat 579 542 37 1 37 Paraquat + 2,4-DB 579 570 3 6 9 Alfalfa 4» Smooth Brome 622 540 82 0 0 0 Alfalfa + Orchardgrass 620 509 109 2 0 2 Alfalfa + Timothy Grass 599 545 51 2 0 2 Oats (killed with herb.) 608 600 9 0 9 Oats (harv. for silage) 567 547 I3 7 20 Oats (harv. for grain) 486 418 36 32 68 LSDmm' 59 68 26 15 29 Harvest 2 No Herbicide 328 319 5 3 8 Paraquat 358 341 1 I6 17 Paraquat + 2.4-DB 342 333 0 9 9 Alfalfa + Smooth Brome 325 308 6 2 10 12 Alfalfa + Orchardgrass 340 294 46 0 0 0 Alfalfa + Timothy Grass 327 322 3 I 2 I Oats (killed with herb.) 355 348 7 0 7 Oats (harv. for silage) 337 323 10 4 l4 Oats (harv. for pain) 310 294 12 3 15 LSD‘m' 334 32 9 12 14 Harvest 3 No Herbicide 302 298 1 3 4 Paraquat 281 257 1 22 23 Paraquat + 2,4-DB 304 300 0 4 4 Alfalfa 4» Smooth Brome 324 313 6 3 2 5 Alfalfa + Orchardgass 308 245 63 0 I I Alfalfa + Timothy Grass 331 323 1 1 6 7 Oats (killed with herb.) 298 298 0 0 0 Oats (harv. for silage) 328 324 2 2 4 Oats (harv. for grain) 306 296 1 8 9 LSD(w,' 50 52 N.S. I4 N.S. Harvest 4 A No Herbicide 253 249 2 2 4 Paraquat 262 232 1 28 29 Paraquat + 2,4-DB 263 253 0 10 11 Alfalfa + Smooth Brome 259 253 1 2 3 5 Alfalfa + Orchardgrass 262 201 49 0 13 I3 Alfalfa 4» Timothy Grass 269 265 0 0 3 ‘1 Oats (killed with herb.) 240 240 0 0 0 Oats (harv. for silage) 258 253 2 2 4 Oats (harv. for grain) 258 250 3 6 8 LSDnm' N.S. 38 2 18 18 'Comparisonsvalidwithiooolutmandharvests. "‘1r»aaaaaaaES