of alfalfa Fertilizer applications at establishment should be based on a soil test.In the absence of a soil test,assuming a Birdsfoot trefoil n the row rage daily gain(Ib/day) ng this amount,the fertilizer should be incorporated into the Mean seedbed prior to planting. Heifer production (lb/A) ng is the 30 ent ofa mixed trefoil and grass stand.no nitrogen (N)fertilizer should be needed. Source:Marten et al..:138-145. However.if trefoil makes up less than 30 percent of the mixture.up tN per acre will be needed meet the sheep.Unlike alfalfa,grazed trefoil does not cause animals ftre stand with ferNormure to bloat. first killin frost is known as stockpiling Trefoil is well o比 will reduce the N fixing ability of trefoil and increase the suited for stockpiling since it holds its leaves at maturity and after fro thus mai aining a relatively high level of BirdsoteolyelsSmmRYlaonel-daned ertile soils but is growth. and alfalfa production is not optimal refoil may be a ag Athoughteiolsoedng5ETolaieandf低nitrogenin dvantage make trefoil ideal for pasture.While p seedling establishment has been a major complaint,careful at pH 6.0 me prouce better than poor soils,but its fertility requirements for high yields are similar to those MarnHyPenn aeand Jy H Chemey.oronomy.Comll otAednfirthera facil ,and employment without RSM293Table 4. Performance of heifers when grazing alfalfa and birdsfoot trefoil. Year Alfalfa Birdsfoot trefoil Average daily gain (lb/day) 1 1.39 1.90 2 1.57 1.68 Mean 1.48 1.79 Heifer production (lb/A) 1 309 396 2 392 380 Mean 351 388 Source: Marten et al., Crop Sci. 27:138-145. sheep. Unlike alfalfa, grazed trefoil does not cause animals to bloat. The practice of not harvesting birdsfoot trefoil during the second half of the summer and grazing it in the fall after the first killing frost is known as stockpiling. Trefoil is well suited for stockpiling since it holds its leaves at maturity and after frosts, thus maintaining a relatively high level of quality. Stockpiling also allows root reserves to accumulate during the fall, which improves plant survival and spring growth. FERTILITY Although trefoil seedings will nodulate and fix nitrogen in soils with a pH as low as 4.5, maximum nodulation occurs at pH 6.0-6.5. Lime should be applied to low-pH soils as recommended by a soil test. Trefoil will produce better than alfalfa on poor soils, but its fertility requirements for high yields are similar to those Prepared by Marvin H. Hall, assistant professor of agronomy, Penn State, and Jerry H. Cherney, associate professor of agronomy, Cornell University Issued in furtherance of Cooperative Extension Work, Acts of Congress May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture and the Pennsylvania Legislature. L. F. Hood, Director of Cooperative Extension, The Pennsylvania State University. The Pennsylvania State University is committed to the policy that all persons shall have equal access to programs, facilities, admission, and employment without regard to personal characteristics not related to ability, performance, or qualifications as determined by University policy or by state or federal authorities. The Pennsylvania State University does not discriminate against any person because of age, ancestry, color, disability or handicap, national origin, race, religious creed, sex, sexual orientation, or veteran status. Direct all affirmative action inquiries to the Affirmative Action Office, The Pennsylvania State University, 201 Willard Building, University Park, PA 16802-2801. R5M293 of alfalfa. Fertilizer applications at establishment should be based on a soil test. In the absence of a soil test, assuming a medium-fertility soil, plow down 0-45-135 lb per acre and apply 20-60-20 lb per acre in the row at seeding (banded if possible). When fertilizer recommendations exceed this amount, the fertilizer should be incorporated into the seedbed prior to planting. Soil testing is the best guide for determining fertilizer requirements of established stands of trefoil. When the trefoil makes up more than 30 percent of a mixed trefoil and grass stand, no nitrogen (N) fertilizer should be needed. However, if trefoil makes up less than 30 percent of the mixture, up to 50 lb N per acre will be needed to meet the grass demand for N and to maximize production. Nitrogen fertilization of a trefoil stand with fertilizer N or manure will reduce the N fixing ability of trefoil and increase the competitiveness of grass or weeds that also may be in the stand. SUMMARY Birdsfoot trefoil yields less than alfalfa on well-drained, fertile soils but is superior to alfalfa on soils of marginal fertility and production capabilities. In areas of New York and Pennsylvania where alfalfa production is not optimal, trefoil may be a viable alternative in forage production systems. Its excellent grazing potential and bloat-free advantages make trefoil ideal for pasture. While poor seedling establishment has been a major complaint, careful management at seeding can reduce this problem considerably. Careful harvest or grazing management is necessary, but when properly managed, birdsfoot trefoil will persist and will remain productive for several years